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Sample records for acid decarboxylase inhibitor

  1. Genetics Home Reference: aromatic l-amino acid decarboxylase deficiency

    MedlinePlus

    ... aromatic l-amino acid decarboxylase deficiency aromatic l-amino acid decarboxylase deficiency Enable Javascript to view the expand/ ... PDF Open All Close All Description Aromatic l-amino acid decarboxylase (AADC) deficiency is an inherited disorder that ...

  2. Peripheral Aromatic L-Amino Acids Decarboxylase Inhibitor in Parkinsonism. I. EFFECT ON O-METHYLATED METABOLITES OF L-DOPA-2-14C

    PubMed Central

    Messiha, F. S.; Hsu, T. H.; Bianchine, J. R.

    1972-01-01

    The effects of MK-486, an inhibitor of peripheral aromatic L-amino acids decarboxylase, on the urinary metabolites derived from orally administered L-Dopa-2-14C were studied in three Parkinsonian patients. Treatment with MK-486 before L-Dopa-2-14C markedly reduced radioactivity found in catecholamines fraction by 70-80% during 48 hr, but increased 3-O-methyldopa fraction by threefold, as compared with a nonpretreated base line value. Pretreatment with MK-486 for a period of 1 wk resulted in less inhibition of O-methylated amine and acid metabolite fractions than that measured after a single dose of the inhibitor. PMID:5009125

  3. A porphomethene inhibitor of uroporphyrinogen decarboxylase causes porphyria cutanea tarda

    PubMed Central

    Phillips, John D.; Bergonia, Hector A.; Reilly, Christopher A.; Franklin, Michael R.; Kushner, James P.

    2007-01-01

    Porphyria cutanea tarda (PCT), the most common form of porphyria in humans, is due to reduced activity of uroporphyrinogen decarboxylase (URO-D) in the liver. Previous studies have demonstrated that protein levels of URO-D do not change when catalytic activity is reduced, suggesting that an inhibitor of URO-D is generated in hepatocytes. Here, we describe the identification and characterization of an inhibitor of URO-D in liver cytosolic extracts from two murine models of PCT: wild-type mice treated with iron, δ-aminolevulinic acid, and polychlorinated biphenyls; and mice with one null allele of Uro-d and two null alleles of the hemochromatosis gene (Uro-d+/−, Hfe−/−) that develop PCT with no treatments. In both models, we identified an inhibitor of recombinant human URO-D (rhURO-D). The inhibitor was characterized by solid-phase extraction, chromatography, UV-visible spectroscopy, and mass spectroscopy and proved to be uroporphomethene, a compound in which one bridge carbon in the uroporphyrinogen macrocycle is oxidized. We synthesized uroporphomethene by photooxidation of enzymatically generated uroporphyrinogen I or III. Both uroporphomethenes inhibited rhURO-D, but the III isomer porphomethene was a more potent inhibitor. Finally, we detected an inhibitor of rhURO-D in cytosolic extracts of liver biopsy samples of patients with PCT. These studies define the mechanism underlying clinical expression of the PCT phenotype, namely oxidation of uroporphyrinogen to uroporphomethene, a competitive inhibitor of URO-D. The oxidation reaction is iron-dependent. PMID:17360334

  4. Microdialysis with radiometric monitoring of L-[β-11C]DOPA to assess dopaminergic metabolism: effect of inhibitors of L-amino acid decarboxylase, monoamine oxidase, and catechol-O-methyltransferase on rat striatal dialysate.

    PubMed

    Okada, Maki; Nakao, Ryuji; Hosoi, Rie; Zhang, Ming-Rong; Fukumura, Toshimitsu; Suzuki, Kazutoshi; Inoue, Osamu

    2011-01-01

    The catecholamine, dopamine (DA), is synthesized from 3,4-dihydroxy-L-phenylalanine (L-DOPA) by aromatic L-amino acid decarboxylase (AADC). Dopamine metabolism is regulated by monoamine oxidase (MAO) and catechol-O-methyltransferase (COMT). To measure dopaminergic metabolism, we used microdialysis with radiometric detection to monitor L-[β-(11)C]DOPA metabolites in the extracellular space of the rat striatum. We also evaluated the effects of AADC, MAO, and COMT inhibitors on metabolite profiles. The major early species measured after administration of L-[β-(11)C]DOPA were [(11)C]3,4-dihydroxyphenylacetic acid ([(11)C]DOPAC) and [(11)C]homovanillic acid ([(11)C]HVA) in a 1:1 ratio, which shifted toward [(11)C]HVA with time. An AADC inhibitor increased the uptake of L-[β-(11)C]DOPA and L-3-O-methyl-[(11)C]DOPA and delayed the accumulation of [(11)C]DOPAC and [(11)C]HVA. The MAO and COMT inhibitors increased the production of [(11)C]3-methoxytyramine and [(11)C]DOPAC, respectively. These results reflect the L-DOPA metabolic pathway, suggesting that this method may be useful for assessing dopaminergic metabolism. PMID:20407462

  5. Ornithine decarboxylase antizyme inhibitor 2 regulates intracellular vesicle trafficking

    SciTech Connect

    Kanerva, Kristiina; Maekitie, Laura T.; Baeck, Nils; Andersson, Leif C.

    2010-07-01

    Antizyme inhibitor 1 (AZIN1) and 2 (AZIN2) are proteins that activate ornithine decarboxylase (ODC), the key enzyme of polyamine biosynthesis. Both AZINs release ODC from its inactive complex with antizyme (AZ), leading to formation of the catalytically active ODC. The ubiquitously expressed AZIN1 is involved in cell proliferation and transformation whereas the role of the recently found AZIN2 in cellular functions is unknown. Here we report the intracellular localization of AZIN2 and present novel evidence indicating that it acts as a regulator of vesicle trafficking. We used immunostaining to demonstrate that both endogenous and FLAG-tagged AZIN2 localize to post-Golgi vesicles of the secretory pathway. Immuno-electron microscopy revealed that the vesicles associate mainly with the trans-Golgi network (TGN). RNAi-mediated knockdown of AZIN2 or depletion of cellular polyamines caused selective fragmentation of the TGN and retarded the exocytotic release of vesicular stomatitis virus glycoprotein. Exogenous addition of polyamines normalized the morphological changes and reversed the inhibition of protein secretion. Our findings demonstrate that AZIN2 regulates the transport of secretory vesicles by locally activating ODC and polyamine biosynthesis.

  6. Characterization of Plasmodium phosphatidylserine decarboxylase expressed in yeast and application for inhibitor screening

    PubMed Central

    Choi, Jae-Yeon; Lawres, Lauren; Toh, Justin Y.; Voelker, Dennis R.; Ben Mamoun, Choukri

    2016-01-01

    Summary Phospholipid biosynthesis is critical for the development, differentiation and pathogenesis of several eukaryotic pathogens. Genetic studies have validated the pathway for phosphatidylethanolamine synthesis from phosphatidylserine catalyzed by phosphatidylserine decarboxylase enzymes (PSD) as a suitable target for development of antimicrobials; however no inhibitors of this class of enzymes have been discovered. We show that the Plasmodium falciparum PSD can restore the essential function of the yeast gene in strains requiring PSD for growth. Genetic, biochemical and metabolic analyses demonstrate that amino acids between positions 40 and 70 of the parasite enzyme are critical for proenzyme processing and decarboxylase activity. We used the essential role of Plasmodium PSD in yeast as a tool for screening a library of anti-malarials. One of these compounds is 7-chloro-N-(4-ethoxyphenyl)-4-quinolinamine, an inhibitor with potent activity against P. falciparum, and low toxicity toward mammalian cells. We synthesized an analog of this compound and showed that it inhibits PfPSD activity and eliminates Plasmodium yoelii infection in mice. These results highlight the importance of 4-quinolinamines as a novel class of drugs targeting membrane biogenesis via inhibition of PSD activity PMID:26585333

  7. An inhibitor of ornithine decarboxylase in the thymus and spleen of dexamethasone-treated rats.

    PubMed Central

    Bishop, P B; Young, J; Peng, T; Richards, J F

    1985-01-01

    A marked decrease in activity of ornithine decarboxylase in thymus and spleen occurs soon after treatment of rats with a glucocorticoid. In the present study, evidence was obtained that extracts of these tissues prepared 5 h after administration of dexamethasone, when the enzyme activity is very low, contain an inhibitor of ornithine decarboxylase. The inhibitor is also present at 12 h after treatment and, in lesser amount, at 2.5 h, but was not evident at 24 h. The inhibitory activity was destroyed by treatment with heat or with trypsin, and was not lost on dialysis of the extract. Preliminary experiments indicate that the Mr of the inhibitor is greater than 50 000, which differentiates it from antizyme, an inhibitor of ornithine decarboxylase found in several other cell types. The inhibitor seems to act by a non-catalytic and non-competitive mechanism. The inhibition is dependent on the amount of inhibitor and does not change with time. Since inhibition is not changed by dialysis of the inhibitory extract, its activity apparently does not require small-Mr substances. This differentiates it from inhibitors which inactivate ornithine decarboxylase by covalent modification, such as the polyamine-dependent protein kinase or transglutaminase. The formation of this inhibitor is an early event in lymphoid tissues in response to dexamethasone and may be important in causing the inhibition of cell division which precedes the destruction of lymphocytes. PMID:3977859

  8. Branched-chain 2-keto acid decarboxylases derived from Psychrobacter.

    PubMed

    Wei, Jiashi; Timler, Jacobe G; Knutson, Carolann M; Barney, Brett M

    2013-09-01

    The conversion of branched-chain amino acids to branched-chain acids or alcohols is an important aspect of flavor in the food industry and is dependent on the Ehrlich pathway found in certain lactic acid bacteria. A key enzyme in the pathway, the 2-keto acid decarboxylase (KDC), is also of interest in biotechnology applications to produce small branched-chain alcohols that might serve as improved biofuels or other commodity feedstocks. This enzyme has been extensively studied in the model bacterium Lactococcus lactis, but is also found in other bacteria and higher organisms. In this report, distinct homologs of the L. lactis KDC originally annotated as pyruvate decarboxylases from Psychrobacter cryohalolentis K5 and P. arcticus 273-4 were cloned and characterized, confirming a related activity toward specific branched-chain 2-keto acids derived from branched-chain amino acids. Further, KDC activity was confirmed in intact cells and cell-free extracts of P. cryohalolentis K5 grown on both rich and defined media, indicating that the Ehrlich pathway may also be utilized in some psychrotrophs and psychrophiles. A comparison of the similarities and differences in the P. cryohalolentis K5 and P. arcticus 273-4 KDC activities to other bacterial KDCs is presented. PMID:23826991

  9. Purification and characterization of a ferulic acid decarboxylase from Pseudomonas fluorescens.

    PubMed Central

    Huang, Z; Dostal, L; Rosazza, J P

    1994-01-01

    A ferulic acid decarboxylase enzyme which catalyzes the decarboxylation of ferulic acid to 4-hydroxy-3-methoxystyrene was purified from Pseudomonas fluorescens UI 670. The enzyme requires no cofactors and contains no prosthetic groups. Gel filtration estimated an apparent molecular mass of 40.4 (+/- 6%) kDa, whereas sodium dodecyl sulfate-polyacrylamide gel electrophoresis showed a molecular mass of 20.4 kDa, indicating that ferulic acid decarboxylase is a homodimer in solution. The purified enzyme displayed an optimum temperature range of 27 to 30 degrees C, exhibited an optimum pH of 7.3 in potassium phosphate buffer, and had a Km of 7.9 mM for ferulic acid. This enzyme also decarboxylated 4-hydroxycinnamic acid but not 2- or 3-hydroxycinnamic acid, indicating that a hydroxy group para to the carboxylic acid-containing side chain is required for the enzymatic reaction. The enzyme was inactivated by Hg2+, Cu2+, p-chloromercuribenzoic acid, and N-ethylmaleimide, suggesting that sulfhydryl groups are necessary for enzyme activity. Diethyl pyrocarbonate, a histidine-specific inhibitor, did not affect enzyme activity. Images PMID:7928951

  10. Retinoic acid modulation of ultraviolet light-induced epidermal ornithine decarboxylase activity

    SciTech Connect

    Lowe, N.J.; Breeding, J.

    1982-02-01

    Irradiation of skin with ultraviolet light of sunburn range (UVB) leads to a large and rapid induction of the polyamine biosynthetic enzyme ornithine decarboxylase in the epidermis. Induction of epidermal ornithine decarboxylase also occurs following application of the tumor promoting agent 12-0-tetradecanoylphorbol-13 acetate and topical retinoic acid is able to block both this ornithine decarboxylase induction and skin tumor promotion. In the studies described below, topical application of retinoic acid to hairless mouse skin leads to a significant inhibition of UVB-induced epidermal ornithine decarboxylase activity. The degree of this inhibition was dependent on the dose, timing, and frequency of the application of retinoic acid. To show significant inhibition of UVB-induced ornithine decarboxylase the retinoic acid had to be applied within 5 hr of UVB irradiation. If retinoic acid treatment was delayed beyond 7 hr following UVB, then no inhibition of UVB-induced ornithine decarboxylase was observed. The quantities of retinoic acid used (1.7 nmol and 3.4 nmol) have been shown effective at inhibiting 12-0-tetradecanoyl phorbol-13 acetate induced ornithine decarboxylase. The results show that these concentrations of topical retinoic acid applied either before or immediately following UVB irradiation reduces the UVB induction of epidermal ornithine decarboxylase. The effect of retinoic acid in these regimens on UVB-induced skin carcinogenesis is currently under study.

  11. Detection, purification and identification of an endogenous inhibitor of L-Dopa decarboxylase activity from human placenta.

    PubMed

    Vassiliou, Alice-Georgia; Fragoulis, Emmanuel G; Vassilacopoulou, Dido

    2009-06-01

    An endogenous inhibitor of L-Dopa decarboxylase activity was identified and purified from human placenta. The endogenous inhibitor of L-Dopa decarboxylase (Ddc) was localized in the membrane fraction of placental tissue. Treatment of membranes with phosphatidylinositol-specific phospholipase C or proteinase K did not affect membrane-associated Ddc inhibitory activity, suggesting that a population of the inhibitor is embedded within membranes. Purification was achieved by extraction from a nondenaturing polyacrylamide gel. The purification scheme resulted in the isolation of a single 35 kDa band, bearing L-Dopa decarboxylase inhibitory activity. The purified inhibitor was identified as Annexin V. The elucidation of the biological importance of the presence of an L-Dopa decarboxylase activity inhibitor in normal human tissues could provide us with new information leading to the better understanding of the biological pathways that Ddc is involved in. PMID:19005753

  12. The Degradation of 14C-Glutamic Acid by L-Glutamic Acid Decarboxylase.

    ERIC Educational Resources Information Center

    Dougherty, Charles M; Dayan, Jean

    1982-01-01

    Describes procedures and semi-micro reaction apparatus (carbon dioxide trap) to demonstrate how a particular enzyme (L-Glutamic acid decarboxylase) may be used to determine the site or sites of labeling in its substrate (carbon-14 labeled glutamic acid). Includes calculations, solutions, and reagents used. (Author/SK)

  13. Anti-glutamic acid decarboxylase antibody positive neurological syndromes.

    PubMed

    Tohid, Hassaan

    2016-07-01

    A rare kind of antibody, known as anti-glutamic acid decarboxylase (GAD) autoantibody, is found in some patients. The antibody works against the GAD enzyme, which is essential in the formation of gamma aminobutyric acid (GABA), an inhibitory neurotransmitter found in the brain. Patients found with this antibody present with motor and cognitive problems due to low levels or lack of GABA, because in the absence or low levels of GABA patients exhibit motor and cognitive symptoms. The anti-GAD antibody is found in some neurological syndromes, including stiff-person syndrome, paraneoplastic stiff-person syndrome, Miller Fisher syndrome (MFS), limbic encephalopathy, cerebellar ataxia, eye movement disorders, and epilepsy. Previously, excluding MFS, these conditions were calledhyperexcitability disorders. However, collectively, these syndromes should be known as "anti-GAD positive neurological syndromes." An important limitation of this study is that the literature is lacking on the subject, and why patients with the above mentioned neurological problems present with different symptoms has not been studied in detail. Therefore, it is recommended that more research is conducted on this subject to obtain a better and deeper understanding of these anti-GAD antibody induced neurological syndromes. PMID:27356651

  14. Glutamic acid decarboxylase isoform distribution in transgenic mouse septum: an anti-GFP immunofluorescence study.

    PubMed

    Verimli, Ural; Sehirli, Umit S

    2016-09-01

    The septum is a basal forebrain region located between the lateral ventricles in rodents. It consists of lateral and medial divisions. Medial septal projections regulate hippocampal theta rhythm whereas lateral septal projections are involved in processes such as affective functions, memory formation, and behavioral responses. Gamma-aminobutyric acidergic neurons of the septal region possess the 65 and 67 isoforms of the enzyme glutamic acid decarboxylase. Although data on the glutamic acid decarboxylase isoform distribution in the septal region generally appears to indicate glutamic acid decarboxylase 67 dominance, different studies have given inconsistent results in this regard. The aim of this study was therefore to obtain information on the distributions of both of these glutamic acid decarboxylase isoforms in the septal region in transgenic mice. Two animal groups of glutamic acid decarboxylase-green fluorescent protein knock-in transgenic mice were utilized in the experiment. Brain sections from the region were taken for anti-green fluorescent protein immunohistochemistry in order to obtain estimated quantitative data on the number of gamma-aminobutyric acidergic neurons. Following the immunohistochemical procedures, the mean numbers of labeled cells in the lateral and medial septal nuclei were obtained for the two isoform groups. Statistical analysis yielded significant results which indicated that the 65 isoform of glutamic acid decarboxylase predominates in both lateral and medial septal nuclei (unpaired two-tailed t-test p < 0.0001 for LS, p < 0.01 for MS). This study is the first to reveal the dominance of glutamic acid decarboxylase isoform 65 in the septal region in glutamic acid decarboxylase-green fluorescent protein transgenic mice. PMID:26643381

  15. Theoretical study of the reaction mechanism of phenolic acid decarboxylase.

    PubMed

    Sheng, Xiang; Lind, Maria E S; Himo, Fahmi

    2015-12-01

    The cofactor-free phenolic acid decarboxylases (PADs) catalyze the non-oxidative decarboxylation of phenolic acids to their corresponding p-vinyl derivatives. Phenolic acids are toxic to some organisms, and a number of them have evolved the ability to transform these compounds, including PAD-catalyzed reactions. Since the vinyl derivative products can be used as polymer precursors and are also of interest in the food-processing industry, PADs might have potential applications as biocatalysts. We have investigated the detailed reaction mechanism of PAD from Bacillus subtilis using quantum chemical methodology. A number of different mechanistic scenarios have been considered and evaluated on the basis of their energy profiles. The calculations support a mechanism in which a quinone methide intermediate is formed by protonation of the substrate double bond, followed by C-C bond cleavage. A different substrate orientation in the active site is suggested compared to the literature proposal. This suggestion is analogous to other enzymes with p-hydroxylated aromatic compounds as substrates, such as hydroxycinnamoyl-CoA hydratase-lyase and vanillyl alcohol oxidase. Furthermore, on the basis of the calculations, a different active site residue compared to previous proposals is suggested to act as the general acid in the reaction. The mechanism put forward here is consistent with the available mutagenesis experiments and the calculated energy barrier is in agreement with measured rate constants. The detailed mechanistic understanding developed here might be extended to other members of the family of PAD-type enzymes. It could also be useful to rationalize the recently developed alternative promiscuous reactivities of these enzymes. PMID:26408050

  16. Epilepsy and hippocampal neurodegeneration induced by glutamate decarboxylase inhibitors in awake rats.

    PubMed

    Salazar, Patricia; Tapia, Ricardo

    2015-10-01

    Glutamic acid decarboxylase (GAD), the enzyme responsible for GABA synthesis, requires pyridoxal phosphate (PLP) as a cofactor. Thiosemicarbazide (TSC) and γ-glutamyl-hydrazone (PLPGH) inhibit the free PLP-dependent isoform (GAD65) activity after systemic administration, leading to epilepsy in mice and in young, but not in adult rats. However, the competitive GAD inhibitor 3-mercaptopropionic acid (MPA) induces convulsions in both immature and adult rats. In the present study we tested comparatively the epileptogenic and neurotoxic effects of PLPGH, TSC and MPA, administered by microdialysis in the hippocampus of adult awake rats. Cortical EEG and motor behavior were analyzed during the next 2h, and aspartate, glutamate and GABA were measured by HPLC in the microdialysis-collected fractions. Twenty-four hours after drug administration rats were fixed for histological analysis of the hippocampus. PLPGH or TSC did not affect the motor behavior, EEG or cellular morphology, although the extracellular concentration of GABA was decreased. In contrast, MPA produced intense wet-dog shakes, EEG epileptiform discharges, a >75% reduction of extracellular GABA levels and remarkable neurodegeneration of the CA1 region, with >80% neuronal loss. The systemic administration of the NMDA glutamate receptor antagonist MK-801 30 min before MPA did not prevent the MPA-induced epilepsy but significantly protected against its neurotoxic effect, reducing neuronal loss to <30%. We conclude that in adult awake rats, drugs acting on PLP availability have only a weak effect on GABA neurotransmission, whereas direct GAD inhibition produced by MPA induces hyperexcitation leading to epilepsy and hippocampal neurodegeneration. Because this degeneration was prevented by the blockade of NMDA receptors, we conclude that it is due to glutamate-mediated excitotoxicity consequent to disinhibition of the hippocampal excitatory circuits. PMID:26354164

  17. Gene therapy for aromatic L-amino acid decarboxylase deficiency.

    PubMed

    Hwu, Wuh-Liang; Muramatsu, Shin-ichi; Tseng, Sheng-Hong; Tzen, Kai-Yuan; Lee, Ni-Chung; Chien, Yin-Hsiu; Snyder, Richard O; Byrne, Barry J; Tai, Chun-Hwei; Wu, Ruey-Meei

    2012-05-16

    Aromatic L-amino acid decarboxylase (AADC) is required for the synthesis of the neurotransmitters dopamine and serotonin. Children with defects in the AADC gene show compromised development, particularly in motor function. Drug therapy has only marginal effects on some of the symptoms and does not change early childhood mortality. Here, we performed adeno-associated viral vector-mediated gene transfer of the human AADC gene bilaterally into the putamen of four patients 4 to 6 years of age. All of the patients showed improvements in motor performance: One patient was able to stand 16 months after gene transfer, and the other three patients achieved supported sitting 6 to 15 months after gene transfer. Choreic dyskinesia was observed in all patients, but this resolved after several months. Positron emission tomography revealed increased uptake by the putamen of 6-[(18)F]fluorodopa, a tracer for AADC. Cerebrospinal fluid analysis showed increased dopamine and serotonin levels after gene transfer. Thus, gene therapy targeting primary AADC deficiency is well tolerated and leads to improved motor function. PMID:22593174

  18. Stimulation of Lysine Decarboxylase Production in Escherichia coli by Amino Acids and Peptides1

    PubMed Central

    Cascieri, T.; Mallette, M. F.

    1973-01-01

    A commercial hydrolysate of casein stimulated production of lysine decarboxylase (EC 4.1.1.18) by Escherichia coli B. Cellulose and gel chromatography of this hydrolysate yielded peptides which were variably effective in this stimulation. Replacement of individual, stimulatory peptides by equivalent amino acids duplicated the enzyme levels attained with those peptides. There was no indication of specific stimulation by any peptide. The peptides were probably taken up by the oligopeptide transport system of E. coli and hydrolyzed intracellularly by peptidases to their constituent amino acids for use in enzyme synthesis. Single omission of amino acids from mixtures was used to screen them for their relative lysine decarboxylase stimulating abilities. Over 100 different mixtures were evaluated in establishing the total amino acid requirements for maximal synthesis of lysine decarboxylase by E. coli B. A mixture containing all of the common amino acids except glutamic acid, aspartic acid, and alanine increased lysine decarboxylase threefold over an equivalent weight of casein hydrolysate. The nine most stimulatory amino acids were methionine, arginine, cystine, leucine, isoleucine, glutamine, threonine, tyrosine, and asparagine. Methionine and arginine quantitatively were the most important. A mixture of these nine was 87% as effective as the complete mixture. Several amino acids were inhibitory at moderate concentrations, and alanine (2.53 mM) was the most effective. Added pyridoxine increased lysine decarboxylase activity 30%, whereas other B vitamins and cyclic adenosine 5′-monophosphate had no effect. PMID:4588201

  19. Influence of ornithine decarboxylase antizymes and antizyme inhibitors on agmatine uptake by mammalian cells.

    PubMed

    Ramos-Molina, Bruno; López-Contreras, Andrés J; Lambertos, Ana; Dardonville, Christophe; Cremades, Asunción; Peñafiel, Rafael

    2015-05-01

    Agmatine (4-aminobutylguanidine), a dicationic molecule at physiological pH, exerts relevant modulatory actions at many different molecular target sites in mammalian cells, having been suggested that the administration of this compound may have therapeutic interest. Several plasma membrane transporters have been implicated in agmatine uptake by mammalian cells. Here we report that in kidney-derived COS-7 cell line, at physiological agmatine levels, the general polyamine transporter participates in the plasma membrane translocation of agmatine, with an apparent Km of 44 ± 7 µM and Vmax of 17.3 ± 3.3 nmol h(-1) mg(-1) protein, but that at elevated concentrations, agmatine can be also taken up by other transport systems. In the first case, the physiological polyamines (putrescine, spermidine and spermine), several diguanidines and bis(2-aminoimidazolines) and the polyamine transport inhibitor AMXT-1501 markedly decreased agmatine uptake. In cells transfected with any of the three ornithine decarboxylase antizymes (AZ1, AZ2 and AZ3), agmatine uptake was dramatically reduced. On the contrary, transfection with antizyme inhibitors (AZIN1 and AZIN2) markedly increased the transport of agmatine. Furthermore, whereas putrescine uptake was significantly decreased in cells transfected with ornithine decarboxylase (ODC), the accumulation of agmatine was stimulated, suggesting a trans-activating effect of intracellular putrescine on agmatine uptake. All these results indicate that ODC and its regulatory proteins (antizymes and antizyme inhibitors) may influence agmatine homeostasis in mammalian tissues. PMID:25655388

  20. Paraneoplastic Neurological Syndromes and Glutamic Acid Decarboxylase Antibodies

    PubMed Central

    Ariño, Helena; Höftberger, Romana; Gresa-Arribas, Nuria; Martínez-Hernandez, Eugenia; Armangue, Thaís; Kruer, Michael C.; Arpa, Javier; Domingo, Julio; Rojc, Bojan; Bataller, Luis; Saiz, Albert; Dalmau, Josep; Graus, Francesc

    2016-01-01

    IMPORTANCE Little is known of glutamic acid decarboxylase antibodies (GAD-abs) in the paraneoplastic context. Clinical recognition of such cases will lead to prompt tumor diagnosis and appropriate treatment. OBJECTIVE To report the clinical and immunological features of patients with paraneoplastic neurological syndromes (PNS) and GAD-abs. DESIGN, SETTING, AND PARTICIPANTS Retrospective case series study and immunological investigations conducted in February 2014 in a center for autoimmune neurological disorders. Fifteen cases with GAD65-abs evaluated between 1995 and 2013 who fulfilled criteria of definite or possible PNS without concomitant onconeural antibodies were included in this study. MAIN OUTCOMES AND MEASURES Analysis of the clinical records of 15 patients and review of 19 previously reported cases. Indirect immunofluorescence with rat hippocampal neuronal cultures and cell-based assays with known neuronal cell-surface antigens were used. One hundred six patients with GAD65-abs and no cancer served as control individuals. RESULTS Eight of the 15 patients with cancer presented as classic paraneoplastic syndromes (5 limbic encephalitis, 1 paraneoplastic encephalomyelitis, 1 paraneoplastic cerebellar degeneration, and 1 opsoclonus-myoclonus syndrome). When compared with the 106 non-PNS cases, those with PNS were older (median age, 60 years vs 48 years; P = .03), more frequently male (60% vs 13%; P < .001), and had more often coexisting neuronal cell-surface antibodies, mainly against γ-aminobutyric acid receptors (53%vs 11%; P < .001). The tumors more frequently involved were lung (n = 6) and thymic neoplasms (n = 4). The risk for an underlying tumor was higher if the presentation was a classic PNS, if it was different from stiff-person syndrome or cerebellar ataxia (odds ratio, 10.5; 95%CI, 3.2–34.5), or if the patient had coexisting neuronal cell-surface antibodies (odds ratio, 6.8; 95%CI, 1.1–40.5). Compared with the current series, the 19 previously

  1. Herbacetin Is a Novel Allosteric Inhibitor of Ornithine Decarboxylase with Antitumor Activity.

    PubMed

    Kim, Dong Joon; Roh, Eunmiri; Lee, Mee-Hyun; Oi, Naomi; Lim, Do Young; Kim, Myoung Ok; Cho, Yong-Yeon; Pugliese, Angelo; Shim, Jung-Hyun; Chen, Hanyong; Cho, Eun Jin; Kim, Jong-Eun; Kang, Sun Chul; Paul, Souren; Kang, Hee Eun; Jung, Ji Won; Lee, Sung-Young; Kim, Sung-Hyun; Reddy, Kanamata; Yeom, Young Il; Bode, Ann M; Dong, Zigang

    2016-03-01

    Ornithine decarboxylase (ODC) is a rate-limiting enzyme in the first step of polyamine biosynthesis that is associated with cell growth and tumor formation. Existing catalytic inhibitors of ODC have lacked efficacy in clinical testing or displayed unacceptable toxicity. In this study, we report the identification of an effective and nontoxic allosteric inhibitor of ODC. Using computer docking simulation and an in vitro ODC enzyme assay, we identified herbacetin, a natural compound found in flax and other plants, as a novel ODC inhibitor. Mechanistic investigations defined aspartate 44 in ODC as critical for binding. Herbacetin exhibited potent anticancer activity in colon cancer cell lines expressing high levels of ODC. Intraperitoneal or oral administration of herbacetin effectively suppressed HCT116 xenograft tumor growth and also reduced the number and size of polyps in a mouse model of APC-driven colon cancer (ApcMin/+). Unlike the well-established ODC inhibitor DFMO, herbacetin treatment was not associated with hearing loss. Taken together, our findings defined the natural product herbacetin as an allosteric inhibitor of ODC with chemopreventive and antitumor activity in preclinical models of colon cancer, prompting its further investigation in clinical trials. PMID:26676750

  2. Production of Dopamine by Aromatic l-Amino Acid Decarboxylase Cells after Spinal Cord Injury.

    PubMed

    Ren, Li-Qun; Wienecke, Jacob; Hultborn, Hans; Zhang, Mengliang

    2016-06-15

    Aromatic l-amino acid decarboxylase (AADC) cells are widely distributed in the spinal cord, and their functions are largely unknown. We have previously found that AADC cells in the spinal cord could increase their ability to produce serotonin (5-hydroxytryptamine) from 5-hydroxytryptophan after spinal cord injury (SCI). Because AADC is a common enzyme catalyzing 5-hydroxytryptophan to serotonin and l-3,4-dihydroxyphenylalanine (l-dopa) to dopamine (DA), it seems likely that the ability of AADC cells using l-dopa to synthesize DA is also increased. To prove whether or not this is the case, a similar rat sacral SCI model and a similar experimental paradigm were adopted as that which we had used previously. In the chronic SCI rats (> 45 days), no AADC cells expressed DA if there was no exogenous l-dopa application. However, following administration of a peripheral AADC inhibitor (carbidopa) with or without a monoamine oxidase inhibitor (pargyline) co-application, systemic administration of l-dopa resulted in ∼94% of AADC cells becoming DA-immunopositive in the spinal cord below the lesion, whereas in normal or sham-operated rats none or very few of AADC cells became DA-immunopositive with the same treatment. Using tail electromyography, spontaneous tail muscle activity was increased nearly fivefold over the baseline level. When pretreated with a central AADC inhibitor (NSD-1015), further application of l-dopa failed to increase the motoneuron activity although the expression of DA in the AADC cells was not completely inhibited. These findings demonstrate that AADC cells in the spinal cord below the lesion gain the ability to produce DA from its precursor in response to SCI. This ability also enables the AADC cells to produce 5-HT and trace amines, and likely contributes to the development of hyperexcitability. These results might also be implicated for revealing the pathological mechanisms underlying l-dopa-induced dyskinesia in Parkinson's disease. PMID:26830512

  3. Substrate Specificity of Thiamine Pyrophosphate-Dependent 2-Oxo-Acid Decarboxylases in Saccharomyces cerevisiae

    PubMed Central

    Romagnoli, Gabriele; Luttik, Marijke A. H.; Kötter, Peter; Pronk, Jack T.

    2012-01-01

    Fusel alcohols are precursors and contributors to flavor and aroma compounds in fermented beverages, and some are under investigation as biofuels. The decarboxylation of 2-oxo acids is a key step in the Ehrlich pathway for fusel alcohol production. In Saccharomyces cerevisiae, five genes share sequence similarity with genes encoding thiamine pyrophosphate-dependent 2-oxo-acid decarboxylases (2ODCs). PDC1, PDC5, and PDC6 encode differentially regulated pyruvate decarboxylase isoenzymes; ARO10 encodes a 2-oxo-acid decarboxylase with broad substrate specificity, and THI3 has not yet been shown to encode an active decarboxylase. Despite the importance of fusel alcohol production in S. cerevisiae, the substrate specificities of these five 2ODCs have not been systematically compared. When the five 2ODCs were individually overexpressed in a pdc1Δ pdc5Δ pdc6Δ aro10Δ thi3Δ strain, only Pdc1, Pdc5, and Pdc6 catalyzed the decarboxylation of the linear-chain 2-oxo acids pyruvate, 2-oxo-butanoate, and 2-oxo-pentanoate in cell extracts. The presence of a Pdc isoenzyme was also required for the production of n-propanol and n-butanol in cultures grown on threonine and norvaline, respectively, as nitrogen sources. These results demonstrate the importance of pyruvate decarboxylases in the natural production of n-propanol and n-butanol by S. cerevisiae. No decarboxylation activity was found for Thi3 with any of the substrates tested. Only Aro10 and Pdc5 catalyzed the decarboxylation of the aromatic substrate phenylpyruvate, with Aro10 showing superior kinetic properties. Aro10, Pdc1, Pdc5, and Pdc6 exhibited activity with all branched-chain and sulfur-containing 2-oxo acids tested but with markedly different decarboxylation kinetics. The high affinity of Aro10 identified it as a key contributor to the production of branched-chain and sulfur-containing fusel alcohols. PMID:22904058

  4. Substrate specificity of thiamine pyrophosphate-dependent 2-oxo-acid decarboxylases in Saccharomyces cerevisiae.

    PubMed

    Romagnoli, Gabriele; Luttik, Marijke A H; Kötter, Peter; Pronk, Jack T; Daran, Jean-Marc

    2012-11-01

    Fusel alcohols are precursors and contributors to flavor and aroma compounds in fermented beverages, and some are under investigation as biofuels. The decarboxylation of 2-oxo acids is a key step in the Ehrlich pathway for fusel alcohol production. In Saccharomyces cerevisiae, five genes share sequence similarity with genes encoding thiamine pyrophosphate-dependent 2-oxo-acid decarboxylases (2ODCs). PDC1, PDC5, and PDC6 encode differentially regulated pyruvate decarboxylase isoenzymes; ARO10 encodes a 2-oxo-acid decarboxylase with broad substrate specificity, and THI3 has not yet been shown to encode an active decarboxylase. Despite the importance of fusel alcohol production in S. cerevisiae, the substrate specificities of these five 2ODCs have not been systematically compared. When the five 2ODCs were individually overexpressed in a pdc1Δ pdc5Δ pdc6Δ aro10Δ thi3Δ strain, only Pdc1, Pdc5, and Pdc6 catalyzed the decarboxylation of the linear-chain 2-oxo acids pyruvate, 2-oxo-butanoate, and 2-oxo-pentanoate in cell extracts. The presence of a Pdc isoenzyme was also required for the production of n-propanol and n-butanol in cultures grown on threonine and norvaline, respectively, as nitrogen sources. These results demonstrate the importance of pyruvate decarboxylases in the natural production of n-propanol and n-butanol by S. cerevisiae. No decarboxylation activity was found for Thi3 with any of the substrates tested. Only Aro10 and Pdc5 catalyzed the decarboxylation of the aromatic substrate phenylpyruvate, with Aro10 showing superior kinetic properties. Aro10, Pdc1, Pdc5, and Pdc6 exhibited activity with all branched-chain and sulfur-containing 2-oxo acids tested but with markedly different decarboxylation kinetics. The high affinity of Aro10 identified it as a key contributor to the production of branched-chain and sulfur-containing fusel alcohols. PMID:22904058

  5. UDP-Glucuronic Acid Decarboxylases of Bacteroides fragilis and Their Prevalence in Bacteria▿†

    PubMed Central

    Coyne, Michael J.; Fletcher, C. Mark; Reinap, Barbara; Comstock, Laurie E.

    2011-01-01

    Xylose is rarely described as a component of bacterial glycans. UDP-xylose is the nucleotide-activated form necessary for incorporation of xylose into glycans and is synthesized by the decarboxylation of UDP-glucuronic acid (UDP-GlcA). Enzymes with UDP-GlcA decarboxylase activity include those that lead to the formation of UDP-xylose as the end product (Uxs type) and those synthesizing UDP-xylose as an intermediate (ArnA and RsU4kpxs types). In this report, we identify and confirm the activities of two Uxs-type UDP-GlcA decarboxylases of Bacteroides fragilis, designated BfUxs1 and BfUxs2. Bfuxs1 is located in a conserved region of the B. fragilis genome, whereas Bfuxs2 is in the heterogeneous capsular polysaccharide F (PSF) biosynthesis locus. Deletion of either gene separately does not result in the loss of a detectable phenotype, but deletion of both genes abrogates PSF synthesis, strongly suggesting that they are functional paralogs and that the B. fragilis NCTC 9343 PSF repeat unit contains xylose. UDP-GlcA decarboxylases are often annotated incorrectly as NAD-dependent epimerases/dehydratases; therefore, their prevalence in bacteria is underappreciated. Using available structural and mutational data, we devised a sequence pattern to detect bacterial genes encoding UDP-GlcA decarboxylase activity. We identified 826 predicted UDP-GlcA decarboxylase enzymes in diverse bacterial species, with the ArnA and RsU4kpxs types confined largely to proteobacterial species. These data suggest that xylose, or a monosaccharide requiring a UDP-xylose intermediate, is more prevalent in bacterial glycans than previously appreciated. Genes encoding BfUxs1-like enzymes are highly conserved in Bacteroides species, indicating that these abundant intestinal microbes may synthesize a conserved xylose-containing glycan. PMID:21804000

  6. Induction of histidine decarboxylase in macrophages inhibited by the novel NF-{kappa}B inhibitor (-)-DHMEQ

    SciTech Connect

    Suzuki, Eriko Ninomiya, Yoko; Umezawa, Kazuo

    2009-02-06

    Histamine often causes inflammation, and this amine is produced by histidine decarboxylase (HDC). We found that (-)-DHMEQ, an NF-{kappa}B inhibitor, inhibited lipopolysaccharide (LPS)-induced histamine production and HDC induction in mouse macrophage cell line RAW264.7. However, as there is no {kappa}B site in the HDC promoter, we studied the mechanism of inhibition. Knockdown of the transcription factor C/EBP{beta} reduced the HDC expression in LPS-treated cells. (-)-DHMEQ inhibited the C/EBP{beta} transcriptional activity in a reporter assay and in an electrophoresis mobility shift assay. But it did not inhibit the in vitro binding of C/EBP{beta} to DNA. It also did not lower the nuclear amount of C/EBP{beta}. On the other hand, the addition of recombinant p65, a component of NF-{kappa}B, enhanced the activity of C/EBP{beta} acting as a cofactor in vitro. Then, we found that (-)-DHMEQ lowered the nuclear amount of p65. Thus, inhibition of the C/EBP{beta} activity by (-)-DHMEQ would be due to a reduction in the amount of nuclear p65, which has a co-activator activity for C/EBP{beta} that is essential for the HDC induction. (-)-DHMEQ may be useful as an anti-inflammatory agent by lowering the histamine production in the body.

  7. Polyamine metabolism and osmotic stress. II. Improvement of oat protoplasts by an inhibitor of arginine decarboxylase

    NASA Technical Reports Server (NTRS)

    Tiburcio, A. F.; Kaur-Sawhney, R.; Galston, A. W.

    1986-01-01

    We have attempted to improve the viability of cereal mesophyll protoplasts by pretreatment of leaves with DL-alpha-difluoromethylarginine (DFMA), a specific 'suicide' inhibitor of the enzyme (arginine decarboxylase) responsible for their osmotically induced putrescine accumulation. Leaf pretreatment with DFMA before a 6 hour osmotic shock caused a 45% decrease of putrescine and a 2-fold increase of spermine titer. After 136 hours of osmotic stress, putrescine titer in DFMA-pretreated leaves increased by only 50%, but spermidine and spermine titers increased dramatically by 3.2- and 6-fold, respectively. These increases in higher polyamines could account for the reduced chlorophyll loss and enhanced ability of pretreated leaves to incorporate tritiated thymidine, uridine, and leucine into macromolecules. Pretreatment with DFMA significantly improved the overall viability of the protoplasts isolated from these leaves. The results support the view that the osmotically induced rise in putrescine and blockage of its conversion to higher polyamines may contribute to the lack of sustained cell division in cereal mesophyll protoplasts, although other undefined factors must also play a major role.

  8. Physiological characterization of the ARO10-dependent, broad-substrate-specificity 2-oxo acid decarboxylase activity of Saccharomyces cerevisiae.

    PubMed

    Vuralhan, Zeynep; Luttik, Marijke A H; Tai, Siew Leng; Boer, Viktor M; Morais, Marcos A; Schipper, Dick; Almering, Marinka J H; Kötter, Peter; Dickinson, J Richard; Daran, Jean-Marc; Pronk, Jack T

    2005-06-01

    Aerobic, glucose-limited chemostat cultures of Saccharomyces cerevisiae CEN.PK113-7D were grown with different nitrogen sources. Cultures grown with phenylalanine, leucine, or methionine as a nitrogen source contained high levels of the corresponding fusel alcohols and organic acids, indicating activity of the Ehrlich pathway. Also, fusel alcohols derived from the other two amino acids were detected in the supernatant, suggesting the involvement of a common enzyme activity. Transcript level analysis revealed that among the five thiamine-pyrophospate-dependent decarboxylases (PDC1, PDC5, PDC6, ARO10, and THI3), only ARO10 was transcriptionally up-regulated when phenylalanine, leucine, or methionine was used as a nitrogen source compared to growth on ammonia, proline, and asparagine. Moreover, 2-oxo acid decarboxylase activity measured in cell extract from CEN.PK113-7D grown with phenylalanine, methionine, or leucine displayed similar broad-substrate 2-oxo acid decarboxylase activity. Constitutive expression of ARO10 in ethanol-limited chemostat cultures in a strain lacking the five thiamine-pyrophosphate-dependent decarboxylases, grown with ammonia as a nitrogen source, led to a measurable decarboxylase activity with phenylalanine-, leucine-, and methionine-derived 2-oxo acids. Moreover, even with ammonia as the nitrogen source, these cultures produced significant amounts of the corresponding fusel alcohols. Nonetheless, the constitutive expression of ARO10 in an isogenic wild-type strain grown in a glucose-limited chemostat with ammonia did not lead to any 2-oxo acid decarboxylase activity. Furthermore, even when ARO10 was constitutively expressed, growth with phenylalanine as the nitrogen source led to increased decarboxylase activities in cell extracts. The results reported here indicate the involvement of posttranscriptional regulation and/or a second protein in the ARO10-dependent, broad-substrate-specificity decarboxylase activity. PMID:15933030

  9. Snapshot of a Reaction Intermediate: Analysis of Benzoylformate Decarboxylase in Complex with a Benzoylphosphonate Inhibitor

    SciTech Connect

    Brandt, Gabriel S.; Kneen, Malea M.; Chakraborty, Sumit; Baykal, Ahmet T.; Nemeria, Natalia; Yep, Alejandra; Ruby, David I.; Petsko, Gregory A.; Kenyon, George L.; McLeish, Michael J.; Jordan, Frank; Ringe, Dagmar

    2009-04-22

    Benzoylformate decarboxylase (BFDC) is a thiamin diphosphate- (ThDP-) dependent enzyme acting on aromatic substrates. In addition to its metabolic role in the mandelate pathway, BFDC shows broad substrate specificity coupled with tight stereo control in the carbon-carbon bond-forming reverse reaction, making it a useful biocatalyst for the production of chiral-hydroxy ketones. The reaction of methyl benzoylphosphonate (MBP), an analogue of the natural substrate benzoylformate, with BFDC results in the formation of a stable analogue (C2{alpha}-phosphonomandelyl-ThDP) of the covalent ThDP-substrate adduct C2{alpha}-mandelyl-ThDP. Formation of the stable adduct is confirmed both by formation of a circular dichroism band characteristic of the 1',4'-iminopyrimidine tautomeric form of ThDP (commonly observed when ThDP forms tetrahedral complexes with its substrates) and by high-resolution mass spectrometry of the reaction mixture. In addition, the structure of BFDC with the MBP inhibitor was solved by X-ray crystallography to a spatial resolution of 1.37 {angstrom} (PDB ID 3FSJ). The electron density clearly shows formation of a tetrahedral adduct between the C2 atom of ThDP and the carbonyl carbon atom of the MBP. This adduct resembles the intermediate from the penultimate step of the carboligation reaction between benzaldehyde and acetaldehyde. The combination of real-time kinetic information via stopped-flow circular dichroism with steady-state data from equilibrium circular dichroism measurements and X-ray crystallography reveals details of the first step of the reaction catalyzed by BFDC. The MBP-ThDP adduct on BFDC is compared to the recently solved structure of the same adduct on benzaldehyde lyase, another ThDP-dependent enzyme capable of catalyzing aldehyde condensation with high stereospecificity.

  10. Biochemical Evaluation of the Decarboxylation and Decarboxylation-Deamination Activities of Plant Aromatic Amino Acid Decarboxylases*

    PubMed Central

    Torrens-Spence, Michael P.; Liu, Pingyang; Ding, Haizhen; Harich, Kim; Gillaspy, Glenda; Li, Jianyong

    2013-01-01

    Plant aromatic amino acid decarboxylase (AAAD) enzymes are capable of catalyzing either decarboxylation or decarboxylation-deamination on various combinations of aromatic amino acid substrates. These two different activities result in the production of arylalkylamines and the formation of aromatic acetaldehydes, respectively. Variations in product formation enable individual enzymes to play different physiological functions. Despite these catalytic variations, arylalkylamine and aldehyde synthesizing AAADs are indistinguishable without protein expression and characterization. In this study, extensive biochemical characterization of plant AAADs was performed to identify residues responsible for differentiating decarboxylation AAADs from aldehyde synthase AAADs. Results demonstrated that a tyrosine residue located on a catalytic loop proximal to the active site of plant AAADs is primarily responsible for dictating typical decarboxylase activity, whereas a phenylalanine at the same position is primarily liable for aldehyde synthase activity. Mutagenesis of the active site phenylalanine to tyrosine in Arabidopsis thaliana and Petroselinum crispum aromatic acetaldehyde synthases primarily converts the enzymes activity from decarboxylation-deamination to decarboxylation. The mutation of the active site tyrosine to phenylalanine in the Catharanthus roseus and Papaver somniferum aromatic amino acid decarboxylases changes the enzymes decarboxylation activity to a primarily decarboxylation-deamination activity. Generation of these mutant enzymes enables the production of unusual AAAD enzyme products including indole-3-acetaldehyde, 4-hydroxyphenylacetaldehyde, and phenylethylamine. Our data indicates that the tyrosine and phenylalanine in the catalytic loop region could serve as a signature residue to reliably distinguish plant arylalkylamine and aldehyde synthesizing AAADs. Additionally, the resulting data enables further insights into the mechanistic roles of active site

  11. Apraxia in anti-glutamic acid decarboxylase-associated stiff person syndrome: link to corticobasal degeneration?

    PubMed

    Bowen, Lauren N; Subramony, S H; Heilman, Kenneth M

    2015-01-01

    Corticobasal syndrome (CBS) is associated with asymmetrical rigidity as well as asymmetrical limb-kinetic and ideomotor apraxia. Stiff person syndrome (SPS) is characterized by muscle stiffness and gait difficulties. Whereas patients with CBS have several forms of pathology, many patients with SPS have glutamic acid decarboxylase antibodies (GAD-ab), but these 2 disorders have not been reported to coexist. We report 2 patients with GAD-ab-positive SPS who also had signs suggestive of CBS, including asymmetrical limb rigidity associated with both asymmetrical limb-kinetic and ideomotor apraxia. Future studies should evaluate patients with CBS for GAD-ab and people with SPS for signs of CBS. PMID:25100431

  12. Regioselective Enzymatic β-Carboxylation of para-Hydroxy- styrene Derivatives Catalyzed by Phenolic Acid Decarboxylases

    PubMed Central

    Wuensch, Christiane; Pavkov-Keller, Tea; Steinkellner, Georg; Gross, Johannes; Fuchs, Michael; Hromic, Altijana; Lyskowski, Andrzej; Fauland, Kerstin; Gruber, Karl; Glueck, Silvia M; Faber, Kurt

    2015-01-01

    We report on a ‘green’ method for the utilization of carbon dioxide as C1 unit for the regioselective synthesis of (E)-cinnamic acids via regioselective enzymatic carboxylation of para-hydroxystyrenes. Phenolic acid decarboxylases from bacterial sources catalyzed the β-carboxylation of para-hydroxystyrene derivatives with excellent regio- and (E/Z)-stereoselectivity by exclusively acting at the β-carbon atom of the C=C side chain to furnish the corresponding (E)-cinnamic acid derivatives in up to 40% conversion at the expense of bicarbonate as carbon dioxide source. Studies on the substrate scope of this strategy are presented and a catalytic mechanism is proposed based on molecular modelling studies supported by mutagenesis of amino acid residues in the active site. PMID:26190963

  13. A glutamic acid decarboxylase (CgGAD) highly expressed in hemocytes of Pacific oyster Crassostrea gigas.

    PubMed

    Li, Meijia; Wang, Lingling; Qiu, Limei; Wang, Weilin; Xin, Lusheng; Xu, Jiachao; Wang, Hao; Song, Linsheng

    2016-10-01

    Glutamic acid decarboxylase (GAD), a rate-limiting enzyme to catalyze the reaction converting the excitatory neurotransmitter glutamate to inhibitory neurotransmitter γ-aminobutyric acid (GABA), not only functions in nervous system, but also plays important roles in immunomodulation in vertebrates. However, GAD has rarely been reported in invertebrates, and never in molluscs. In the present study, one GAD homologue (designed as CgGAD) was identified from Pacific oyster Crassostrea gigas. The full length cDNA of CgGAD was 1689 bp encoding a polypeptide of 562 amino acids containing a conserved pyridoxal-dependent decarboxylase domain. CgGAD mRNA and protein could be detected in ganglion and hemocytes of oysters, and their abundance in hemocytes was unexpectedly much higher than those in ganglion. More importantly, CgGAD was mostly located in those granulocytes without phagocytic capacity in oysters, and could dynamically respond to LPS stimulation. Further, after being transfected into HEK293 cells, CgGAD could promote the production of GABA. Collectively, these findings suggested that CgGAD, as a GABA synthase and molecular marker of GABAergic system, was mainly distributed in hemocytes and ganglion and involved in neuroendocrine-immune regulation network in oysters, which also provided a novel insight to the co-evolution between nervous system and immune system. PMID:27208883

  14. Enhancing muconic acid production from glucose and lignin-derived aromatic compounds via increased protocatechuate decarboxylase activity

    DOE PAGESBeta

    Johnson, Christopher W.; Salvachua, Davinia; Khanna, Payal; Smith, Holly; Peterson, Darren J.; Beckham, Gregg T.

    2016-04-22

    The conversion of biomass-derived sugars and aromatic molecules to cis,cis-muconic acid (referred to hereafter as muconic acid or muconate) has been of recent interest owing to its facile conversion to adipic acid, an important commodity chemical. Metabolic routes to produce muconate from both sugars and many lignin-derived aromatic compounds require the use of a decarboxylase to convert protocatechuate (PCA, 3,4-dihydroxybenzoate) to catechol (1,2-dihydroxybenzene), two central aromatic intermediates in this pathway. Several studies have identified the PCA decarboxylase as a metabolic bottleneck, causing an accumulation of PCA that subsequently reduces muconate production. A recent study showed that activity of the PCAmore » decarboxylase is enhanced by co-expression of two genetically associated proteins, one of which likely produces a flavin-derived cofactor utilized by the decarboxylase. Using entirely genome-integrated gene expression, we have engineered Pseudomonas putida KT2440-derived strains to produce muconate from either aromatic molecules or sugars and demonstrate in both cases that co-expression of these decarboxylase associated proteins reduces PCA accumulation and enhances muconate production relative to strains expressing the PCA decarboxylase alone. In bioreactor experiments, co-expression increased the specific productivity (mg/g cells/h) of muconate from the aromatic lignin monomer p-coumarate by 50% and resulted in a titer of >15 g/L. In strains engineered to produce muconate from glucose, co-expression more than tripled the titer, yield, productivity, and specific productivity, with the best strain producing 4.92+/-0.48 g/L muconate. Furthermore, this study demonstrates that overcoming the PCA decarboxylase bottleneck can increase muconate yields from biomass-derived sugars and aromatic molecules in industrially relevant strains and cultivation conditions.« less

  15. The effect of pyruvate decarboxylase gene knockout in Saccharomyces cerevisiae on L-lactic acid production.

    PubMed

    Ishida, Nobuhiro; Saitoh, Satoshi; Onishi, Toru; Tokuhiro, Kenro; Nagamori, Eiji; Kitamoto, Katsuhiko; Takahashi, Haruo

    2006-05-01

    A plant- and crop-based renewable plastic, poly-lactic acid (PLA), is receiving attention as a new material for a sustainable society in place of petroleum-based plastics. We constructed a metabolically engineered Saccharomyces cerevisiae that has both pyruvate decarboxylase genes (PDC1 and PDC5) disrupted in the genetic background to express two copies of the bovine L-lactate dehydrogenase (LDH) gene. With this recombinant, the yield of lactate was 82.3 g/liter, up to 81.5% of the glucose being transformed into lactic acid on neutralizing cultivation, although pdc1 pdc5 double disruption led to ineffective decreases in cell growth and fermentation speed. This strain showed lactate productivity improvement as much as 1.5 times higher than the previous strain. This production yield is the highest value for a lactic acid-producing yeast yet reported. PMID:16717415

  16. Structure and Mechanism of Ferulic Acid Decarboxylase (FDC1) from Saccharomyces cerevisiae.

    PubMed

    Bhuiya, Mohammad Wadud; Lee, Soon Goo; Jez, Joseph M; Yu, Oliver

    2015-06-15

    The nonoxidative decarboxylation of aromatic acids occurs in a range of microbes and is of interest for bioprocessing and metabolic engineering. Although phenolic acid decarboxylases provide useful tools for bioindustrial applications, the molecular bases for how these enzymes function are only beginning to be examined. Here we present the 2.35-Å-resolution X-ray crystal structure of the ferulic acid decarboxylase (FDC1; UbiD) from Saccharomyces cerevisiae. FDC1 shares structural similarity with the UbiD family of enzymes that are involved in ubiquinone biosynthesis. The position of 4-vinylphenol, the product of p-coumaric acid decarboxylation, in the structure identifies a large hydrophobic cavity as the active site. Differences in the β2e-α5 loop of chains in the crystal structure suggest that the conformational flexibility of this loop allows access to the active site. The structure also implicates Glu285 as the general base in the nonoxidative decarboxylation reaction catalyzed by FDC1. Biochemical analysis showed a loss of enzymatic activity in the E285A mutant. Modeling of 3-methoxy-4-hydroxy-5-decaprenylbenzoate, a partial structure of the physiological UbiD substrate, in the binding site suggests that an ∼30-Å-long pocket adjacent to the catalytic site may accommodate the isoprenoid tail of the substrate needed for ubiquinone biosynthesis in yeast. The three-dimensional structure of yeast FDC1 provides a template for guiding protein engineering studies aimed at optimizing the efficiency of aromatic acid decarboxylation reactions in bioindustrial applications. PMID:25862228

  17. Structure and Mechanism of Ferulic Acid Decarboxylase (FDC1) from Saccharomyces cerevisiae

    PubMed Central

    Bhuiya, Mohammad Wadud; Lee, Soon Goo

    2015-01-01

    The nonoxidative decarboxylation of aromatic acids occurs in a range of microbes and is of interest for bioprocessing and metabolic engineering. Although phenolic acid decarboxylases provide useful tools for bioindustrial applications, the molecular bases for how these enzymes function are only beginning to be examined. Here we present the 2.35-Å-resolution X-ray crystal structure of the ferulic acid decarboxylase (FDC1; UbiD) from Saccharomyces cerevisiae. FDC1 shares structural similarity with the UbiD family of enzymes that are involved in ubiquinone biosynthesis. The position of 4-vinylphenol, the product of p-coumaric acid decarboxylation, in the structure identifies a large hydrophobic cavity as the active site. Differences in the β2e-α5 loop of chains in the crystal structure suggest that the conformational flexibility of this loop allows access to the active site. The structure also implicates Glu285 as the general base in the nonoxidative decarboxylation reaction catalyzed by FDC1. Biochemical analysis showed a loss of enzymatic activity in the E285A mutant. Modeling of 3-methoxy-4-hydroxy-5-decaprenylbenzoate, a partial structure of the physiological UbiD substrate, in the binding site suggests that an ∼30-Å-long pocket adjacent to the catalytic site may accommodate the isoprenoid tail of the substrate needed for ubiquinone biosynthesis in yeast. The three-dimensional structure of yeast FDC1 provides a template for guiding protein engineering studies aimed at optimizing the efficiency of aromatic acid decarboxylation reactions in bioindustrial applications. PMID:25862228

  18. Conversion of levulinic acid to 2-butanone by acetoacetate decarboxylase from Clostridium acetobutylicum.

    PubMed

    Min, Kyoungseon; Kim, Seil; Yum, Taewoo; Kim, Yunje; Sang, Byoung-In; Um, Youngsoon

    2013-06-01

    In this study, a novel system for synthesis of 2-butanone from levulinic acid (γ-keto-acid) via an enzymatic reaction was developed. Acetoacetate decarboxylase (AADC; E.C. 4.1.1.4) from Clostridium acetobutylicum was selected as a biocatalyst for decarboxylation of levulinic acid. The purified recombinant AADC from Escherichia coli successfully converted levulinic acid to 2-butanone with a conversion yield of 8.4-90.3 % depending on the amount of AADC under optimum conditions (30 °C and pH 5.0) despite that acetoacetate, a β-keto-acid, is a natural substrate of AADC. In order to improve the catalytic efficiency, an AADC-mediator system was tested using methyl viologen, methylene blue, azure B, zinc ion, and 2,2-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) as mediators. Among them, methyl viologen showed the best performance, increasing the conversion yield up to 6.7-fold in comparison to that without methyl viologen. The results in this study are significant in the development of a renewable method for the synthesis of 2-butanone from biomass-derived chemical, levulinic acid, through enzymatic decarboxylation. PMID:23624707

  19. Extracellular expression of glutamate decarboxylase B in Escherichia coli to improve gamma-aminobutyric acid production.

    PubMed

    Zhao, Anqi; Hu, Xiaoqing; Li, Ye; Chen, Cheng; Wang, Xiaoyuan

    2016-12-01

    Escherichia coli overexpressing glutamate decarboxylase GadB can produce gamma-aminobutyric acid with addition of monosodium glutamate. The yield and productivity of gamma-aminobutyric acid might be significantly improved if the overexpressed GadB in E. coli cells can be excreted outside, where it can directly transforms monosodium glutamate to gamma-aminobutyric acid. In this study, GadB was fused to signal peptides TorA or PelB, respectively, and overexpressed in E. coli BL21(DE3). It was found that TorA could facilitate GadB secretion much better than PelB. Conditions for GadB secretion and gamma-aminobutyric acid production were optimized in E. coli BL21(DE3)/pET20b-torA-gadB, leading the secretion of more than half of the overexpressed GadB. Fed-batch fermentation for GadB expression and gamma-aminobutyric acid production of BL21(DE3)/pET20b-torA-gadB was sequentially performed in one fermenter; 264.4 and 313.1 g/L gamma-aminobutyric acid were obtained with addition of monosodium glutamate after 36 and 72 h, respectively. PMID:27549808

  20. Novel S-adenosyl-L-methionine decarboxylase inhibitors as potent antiproliferative agents against intraerythrocytic Plasmodium falciparum parasites☆

    PubMed Central

    le Roux, Dina; Burger, Pieter B.; Niemand, Jandeli; Grobler, Anne; Urbán, Patricia; Fernàndez-Busquets, Xavier; Barker, Robert H.; Serrano, Adelfa E.; I. Louw, Abraham; Birkholtz, Lyn-Marie

    2013-01-01

    S-adenosyl-l-methionine decarboxylase (AdoMetDC) in the polyamine biosynthesis pathway has been identified as a suitable drug target in Plasmodium falciparum parasites, which causes the most lethal form of malaria. Derivatives of an irreversible inhibitor of this enzyme, 5′-{[(Z)-4-amino-2-butenyl]methylamino}-5′-deoxyadenosine (MDL73811), have been developed with improved pharmacokinetic profiles and activity against related parasites, Trypanosoma brucei. Here, these derivatives were assayed for inhibition of AdoMetDC from P. falciparum parasites and the methylated derivative, 8-methyl-5′-{[(Z)-4-aminobut-2-enyl]methylamino}-5′-deoxyadenosine (Genz-644131) was shown to be the most active. The in vitro efficacy of Genz-644131 was markedly increased by nanoencapsulation in immunoliposomes, which specifically targeted intraerythrocytic P. falciparum parasites. PMID:24596666

  1. Intrathecal-specific glutamic acid decarboxylase antibodies at low titers in autoimmune neurological disorders.

    PubMed

    Sunwoo, Jun-Sang; Chu, Kon; Byun, Jung-Ick; Moon, Jangsup; Lim, Jung-Ah; Kim, Tae-Joon; Lee, Soon-Tae; Jung, Keun-Hwa; Park, Kyung-Il; Jeon, Daejong; Jung, Ki-Young; Kim, Manho; Lee, Sang Kun

    2016-01-15

    Autoantibodies to glutamic acid decarboxylase (Gad-Abs) are implicated in various neurological syndromes. The present study aims to identify intrathecal-specific GAD-Abs and to determine clinical manifestations and treatment outcomes. Nineteen patients had GAD-Abs in cerebrospinal fluid but not in paired serum samples. Neurological syndromes included limbic encephalitis, temporal lobe epilepsy, cerebellar ataxia, autonomic dysfunction, and stiff-person syndrome. Immunotherapy had beneficial effects in 57.1% of patients, and the patients with limbic encephalitis responded especially well to immunotherapy. Intrathecal-specific antibodies to GAD at low titers may appear as nonspecific markers of immune activation within the central nervous system rather than pathogenic antibodies causing neuronal dysfunction. PMID:26711563

  2. Cloning and primary structure of a human islet isoform of glutamic acid decarboxylase from chromosome 10

    SciTech Connect

    Karlsen, A.E.; Hagopian, W.A.; Grubin, C.E.; Dube, S.; Disteche, C.M.; Adler, D.A.; Baermeier, H.; Lernmark, A. ); Mathewes, S.; Grant, F.J.; Foster, D. )

    1991-10-01

    Glutamic acid decarboxylase which catalyzes formation of {gamma}-aminobutyric acid from L-glutamic acid, is detectable in different isoforms with distinct electrophoretic and kinetic characteristics. GAD has also been implicated as an autoantigen in the vastly differing autoimmune disease stiff-man syndrome and insulin-dependent diabetes mellitus. Despite the differing GAD isoforms, only one type of GAD cDNA (GAD-1), localized to a syntenic region of chromosome 2, has been isolated from rat, mouse, and cat. Using sequence information from GAD-1 to screen a human pancreatic islet cDNA library, the authors describe the isolation of an additional GAD cDNA (GAD-2), which was mapped to the short arm of human chromosome 10. Genomic Southern blotting with GAD-2 demonstrated a hybridization pattern different form that detected by GAD-1. GAD-2 recognizes a 5.6-kilobase transcript in both islets and brain, in contrast to GAD-1, which detects a 3.7-kilobase transcript in brain only. The deduced 585-amino acid sequence coded for by GAD-2 shows < 65% identify to previously published, highly conserved GAD-1 brain sequences, which show > 96% deduced amino acid sequence homology among the three species.

  3. Cysteine Sulfinic Acid Decarboxylase Regulation: A Role for FXR and SHP in Murine Hepatic Taurine Metabolism

    PubMed Central

    Kerr, Thomas A.; Matsumoto, Yuri; Matsumoto, Hitoshi; Xie, Yan; Hirschberger, Lawrence L.; Stipanuk, Martha H.; Anakk, Sayeepriyadarshini; Moore, David D.; Watanabe, Mitsuhiro; Kennedy, Susan

    2014-01-01

    Background Bile acid synthesis is regulated by nuclear receptors including farnesoid X receptor (FXR) and small heterodimer partner (SHP), and by fibroblast growth factor15/19 (FGF15/19). Because bile acid synthesis involves amino acid conjugation, we hypothesized that hepatic cysteine sulfinic acid decarboxylase (CSAD) (a key enzyme in taurine synthesis) is regulated by bile acids. Aims To investigate CSAD regulation by bile acids and CSAD regulatory mechanisms. Methods Mice were fed a control diet or a diet supplemented with either 0.5% cholate or 2% cholestyramine. To gain mechanistic insight into CSAD regulation, we utilized GW4064 (FXR agonist), FGF19, or T-0901317 (LXR agonist) and Shp−/− mice. Tissue mRNA expression was determined by qRT-PCR. Amino acids were measured by HPLC. Results Mice supplemented with dietary cholate exhibited reduced hepatic CSAD mRNA expression while those receiving cholestyramine exhibited increased hepatic CSAD mRNA expression. Activation of FXR suppressed CSAD mRNA expression whereas hepatic CSAD mRNA expression was increased in Shp−/− mice. Hepatic hypotaurine concentration (the product of CSAD) was higher in Shp−/− mice with a corresponding increase in serum (but not hepatic) taurine-conjugated bile acids. FGF19 administration suppressed hepatic CYP7A1 mRNA but did not change CSAD mRNA expression. LXR activation induced CYP7A1 mRNA yet failed to induce CSAD mRNA expression. Conclusion CSAD mRNA expression is physiologically regulated by bile acids in a feedback fashion via mechanisms involving SHP and FXR but not FGF15/19 or LXR. These novel findings implicate bile acids as regulators of CSAD mRNA via mechanisms shared in part with CYP7A1. PMID:24033844

  4. Structural analysis of Bacillus pumilus phenolic acid decarboxylase, a lipocalin-fold enzyme.

    PubMed

    Matte, Allan; Grosse, Stephan; Bergeron, Hélène; Abokitse, Kofi; Lau, Peter C K

    2010-11-01

    The decarboxylation of phenolic acids, including ferulic and p-coumaric acids, to their corresponding vinyl derivatives is of importance in the flavouring and polymer industries. Here, the crystal structure of phenolic acid decarboxylase (PAD) from Bacillus pumilus strain UI-670 is reported. The enzyme is a 161-residue polypeptide that forms dimers both in the crystal and in solution. The structure of PAD as determined by X-ray crystallography revealed a β-barrel structure and two α-helices, with a cleft formed at one edge of the barrel. The PAD structure resembles those of the lipocalin-fold proteins, which often bind hydrophobic ligands. Superposition of structurally related proteins bound to their cognate ligands shows that they and PAD bind their ligands in a conserved location within the β-barrel. Analysis of the residue-conservation pattern for PAD-related sequences mapped onto the PAD structure reveals that the conservation mainly includes residues found within the hydrophobic core of the protein, defining a common lipocalin-like fold for this enzyme family. A narrow cleft containing several conserved amino acids was observed as a structural feature and a potential ligand-binding site. PMID:21045284

  5. Structural analysis of Bacillus pumilus phenolic acid decarboxylase, a lipocalin-fold enzyme

    SciTech Connect

    Matte, Allan; Grosse, Stephan; Bergeron, Hélène; Abokitse, Kofi; Lau, Peter C.K.

    2012-04-30

    The decarboxylation of phenolic acids, including ferulic and p-coumaric acids, to their corresponding vinyl derivatives is of importance in the flavoring and polymer industries. Here, the crystal structure of phenolic acid decarboxylase (PAD) from Bacillus pumilus strain UI-670 is reported. The enzyme is a 161-residue polypeptide that forms dimers both in the crystal and in solution. The structure of PAD as determined by X-ray crystallography revealed a -barrel structure and two -helices, with a cleft formed at one edge of the barrel. The PAD structure resembles those of the lipocalin-fold proteins, which often bind hydrophobic ligands. Superposition of structurally related proteins bound to their cognate ligands shows that they and PAD bind their ligands in a conserved location within the -barrel. Analysis of the residue-conservation pattern for PAD-related sequences mapped onto the PAD structure reveals that the conservation mainly includes residues found within the hydrophobic core of the protein, defining a common lipocalin-like fold for this enzyme family. A narrow cleft containing several conserved amino acids was observed as a structural feature and a potential ligand-binding site.

  6. Molecular and functional analyses of amino acid decarboxylases involved in cuticle tanning in Tribolium castaneum

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Aspartate 1-decarboxylase (ADC) and dopa decarboxylase (DDC) provide b–alanine and dopamine used in insect cuticle tanning. Beta-alanine is conjugated with dopamine to yield N-b-alanyldopamine (NBAD), a substrate for the phenoloxidase laccase that catalyzes the synthesis of cuticle protein cross-li...

  7. POSTTRANSLATIONAL MODIFICATION OF GLUTAMIC ACID DECARBOXYLASE 67 BY INTERMITTENT HYPOXIA: Evidence for the involvement of dopamine D1 receptor signaling$

    PubMed Central

    Raghuraman, Gayatri; Prabhakar, Nanduri R.; Kumar, Ganesh K.

    2010-01-01

    Intermittent hypoxia (IH) associated with sleep apnea leads to cardio-respiratory morbidities. Previous studies have shown that IH alters the synthesis of neurotransmitters including catecholamines and neuropeptides in brainstem regions associated with regulation of cardio-respiratory functions. GABA, a major inhibitory neurotransmitter in the central nervous system, has been implicated in cardio-respiratory control. GABA synthesis is primarily catalyzed by glutamic acid decarboxylase (GAD). Here, we tested the hypothesis that IH like its effect on other transmitters also alters GABA synthesis. The impact of IH on GABA synthesis was investigated in pheochromocytoma 12 (PC12) cells, a neuronal cell line which is known to express active form of GAD67 in the cytosolic fraction and also assessed the underlying mechanisms contributing to IH-evoked response. Exposure of cell cultures to IH decreased GAD67 activity and GABA level. IH-evoked decrease in GAD67 activity was due to increased cAMP - protein kinase A (PKA) - dependent phosphorylation of GAD67, but not as a result of changes in either GAD67 mRNA or protein expression. PKA inhibitor restored GAD67 activity and GABA levels in IH treated cells. PC12 cells express dopamine 1 receptor (D1R), a G-protein coupled receptor whose activation increased adenylyl cyclase (AC) activity. Treatment with either D1R antagonist or AC inhibitor reversed IH-evoked GAD67 inhibition. Silencing D1R expression with siRNA reversed cAMP elevation and GAD67 inhibition by IH. These results provide evidence for the role of D1R-cAMP-PKA signaling in IH mediated inhibition of GAD67 via protein phosphorylation resulting in down regulation of GABA synthesis. PMID:20969567

  8. Cloning and characterization of a locus encoding an indolepyruvate decarboxylase involved in indole-3-acetic acid synthesis in Erwinia herbicola.

    PubMed Central

    Brandl, M T; Lindow, S E

    1996-01-01

    Erwinia herbicola 299R synthesizes indole-3-acetic acid (IAA) primarily by the indole-3-pyruvic acid pathway. A gene involved in the biosynthesis of IAA was cloned from strain 299R. This gene (ipdC) conferred the synthesis of indole-3-acetaldehyde and tryptophol upon Escherichia coli DH5 alpha in cultures supplemented with L-tryptophan. The deduced amino acid sequence of the gene product has high similarity to that of the indolepyruvate decarboxylase of Enterobacter cloacae. Regions within pyruvate decarboxylases of various fungal and plant species also exhibited considerable homology to portions of this gene. This gene therefore presumably encodes an indolepyruvate decarboxylase (IpdC) which catalyzes the conversion of indole-3-pyruvic acid to indole-3-acetaldehyde. Insertions of Tn3-spice within ipdC abolished the ability of strain 299R to synthesize indole-3-acetaldehyde and tryptophol and reduced its IAA production in tryptophan-supplemented minimal medium by approximately 10-fold, thus providing genetic evidence for the role of the indolepyruvate pathway in IAA synthesis in this strain. An ipdC probe hybridized strongly with the genomic DNA of all E. herbicola strains tested in Southern hybridization studies, suggesting that the indolepyruvate pathway is common in this species. Maximum parsimony analysis revealed that the ipdC gene is highly conserved within this group and that strains of diverse geographic origin were very similar with respect to ipdC. PMID:8900003

  9. Rapid glutamic acid decarboxylase test for identification of Bacteroides and Clostridium spp.

    PubMed Central

    Jilly, B J; Schreckenberger, P C; LeBeau, L J

    1984-01-01

    A rapid 4-h test for glutamic acid decarboxylase is described for the identification of certain anaerobic bacteria. The test substrate consisted of 1.0 g of L-glutamic acid, 0.3 ml of Triton X-155, and 0.05 g of bromcresol green sodium salt in 1 liter of water. The substrate was dispensed in 0.5-ml amounts into test tubes, and a turbid suspension was made with the test organism. The test was then incubated aerobically at 35 degrees C for 4 h. The development of a blue color was considered positive. A total of 345 strains of clinically isolated anaerobic bacteria were tested. All isolates of Bacteroides fragilis, Bacteroides thetaiotaomicron, Bacteroides uniformis. Clostridium perfringens, and Clostridium sordellii gave a positive reaction. Some isolates of Bacteroides distasonis and Bacteroides vulgatus were also positive. The use of this rapid test in conjunction with other rapid methods, such as the spot indol test, will enable laboratory workers to report these pathogens on the same day on which an inoculum of pure culture growth on agar is available. PMID:6376535

  10. Non-convulsive status epilepticus associated with glutamic acid decarboxylase antibody.

    PubMed

    Cikrikçili, Ugur; Ulusoy, Canan; Turan, Selin; Yildiz, Senay; Bilgiç, Basar; Hanagasi, Hasmet; Baykan, Betül; Tüzün, Erdem; Gürvit, Hakan

    2013-07-01

    Autoimmune encephalitis associated with glutamic acid decarboxylase antibodies (GAD-Ab) often presents with treatment-resistant partial seizures, as well as other central nervous system symptoms. In contrast to several other well-characterized autoantibodies, GAD-Ab has very rarely been associated with status epilepticus. We report a 63-year-old woman initially admitted with somnolence and psychiatric findings. The EEG findings, of generalized and rhythmical slow spike-wave activity over the posterior regions of both hemispheres, together with the clinical deterioration in responsiveness, led to the diagnosis of non-convulsive status epilepticus. Investigation of a broad panel of autoantibodies, revealed only increased serum GAD-Ab levels. Following methylprednisolone and intravenous immunoglobulin treatments, the patient's neurological symptoms improved, EEG findings disappeared and GAD-Ab levels significantly decreased. GAD-Ab should be added to the list of anti-neuronal antibodies associated with non-convulsive status epilepticus. Disappearance of clinical findings and seroreversion after immunotherapy suggest that GAD-Ab might be involved in seizure pathogenesis.  PMID:23820312

  11. Transcriptional regulation of glutamic acid decarboxylase in the male mouse amygdala by dietary phyto-oestrogens.

    PubMed

    Sandhu, K V; Yanagawa, Y; Stork, O

    2015-04-01

    Phyto-oestrogens are biologically active components of many human and laboratory animal diets. In the present study, we investigated, in adult male mice with C57BL/6 genetic background, the effects of a reduced phyto-oestrogens intake on anxiety-related behaviour and associated gene expression in the amygdala. After 6 weeks on a low-phyto-oestrogen diet (< 20 μg/g cumulative phyto-oestrogen content), animals showed reduced centre exploration in an open-field task compared to their littermates on a soybean-based standard diet (300 μg/g). Freezing behaviour in an auditory fear memory task, in contrast, was not affected. We hypothesised that this mildly increased anxiety may involve changes in the function of GABAergic local circuit neurones in the amygdala. Using GAD67(+/GFP) mice, we could demonstrate reduced transcription of the GAD67 gene in the lateral and basolateral amygdala under the low-phyto-oestrogen diet. Analysis of mRNA levels in microdissected samples confirmed this regulation and demonstrated concomitant changes in expression of the second glutamic acid decarboxylase (GAD) isoform, GAD65, as well as the anxiolytic neuropeptide Y. These molecular and behavioural alterations occurred without apparent changes in circulating oestrogens or testosterone levels. Our data suggest that expression regulation of interneurone-specific gene products in the amygdala may provide a mechanism for the control of anxiety-related behaviour through dietary phyto-oestrogens. PMID:25650988

  12. Effect of retinoic acid on transglutaminase and ornithine decarboxylase activities during liver regeneration.

    PubMed

    Ohtake, Yosuke; Maruko, Akiko; Ohishi, Nao; Kawaguchi, Masasumi; Satoh, Tetsuharu; Ohkubo, Yasuhito

    2008-04-01

    Liver regeneration is regulated by several factors, including growth factors, cytokines, and post-translational modifications of several proteins. It is suggested that transglutaminase 2 (TG2) and ornithine decarboxylase (ODC) are involved in liver regeneration. To investigate the role of TG2 and ODC activities in regenerating liver, we used retinoic acid (RA), an inducer of TG2 and a suppressor of ODC. Regenerating rat liver was prepared by 70% partial hepatectomy (PH). Rats were sacrificed at 1, 2, 3, 4, and 6 days after surgery. RA was intraperitoneally injected immediately after PH. TG2 and ODC activities and products (epsilon-(gamma-glutamyl) lysine isopeptide (Gln-Lys) and polyamines, respectively) were examined at the indicated times. In RA-treated rat, DNA synthesis and ODC activity declined and the peak shifted to 2 days after PH, whereas TG2 activity increased at 1 day after PH. At that time, protein-polyamine, especially the protein-spermidine (SPD) bond, transiently decreased, whereas the formation of the Gln-Lys bond increased after PH. These results suggested that in regenerating liver, enhanced the formation of Gln-Lys bonds catalyzed by TG2 led to reduced DNA synthesis, whereas when ODC produced newly synthesized SPD, the inhibition of Gln-Lys bond production by the preferential formation of protein-SPD bonds led to an increase in DNA synthesis. PMID:18008394

  13. Aromatic L-amino acid decarboxylase deficiency diagnosed by clinical metabolomic profiling of plasma.

    PubMed

    Atwal, Paldeep S; Donti, Taraka R; Cardon, Aaron L; Bacino, C A; Sun, Qin; Emrick, L; Reid Sutton, V; Elsea, Sarah H

    2015-01-01

    Aromatic L-amino acid decarboxylase (AADC) deficiency is an inborn error of metabolism affecting the biosynthesis of serotonin, dopamine, and catecholamines. We report a case of AADC deficiency that was detected using the Global MAPS platform. This is a novel platform that allows for parallel clinical testing of hundreds of metabolites in a single plasma specimen. It uses a state-of-the-art mass spectrometry platform, and the resulting spectra are compared against a library of ~2500 metabolites. Our patient is now a 4 year old boy initially seen at 11 months of age for developmental delay and hypotonia. Multiple tests had not yielded a diagnosis until exome sequencing revealed compound heterozygous variants of uncertain significance (VUS), c.286G>A (p.G96R) and c.260C>T (p.P87L) in the DDC gene, causal for AADC deficiency. CSF neurotransmitter analysis confirmed the diagnosis with elevated 3-methoxytyrosine (3-O-methyldopa). Metabolomic profiling was performed on plasma and revealed marked elevation in 3-methoxytyrosine (Z-score +6.1) consistent with the diagnosis of AADC deficiency. These results demonstrate that the Global MAPS platform is able to diagnose AADC deficiency from plasma. In summary, we report a novel and less invasive approach to diagnose AADC deficiency using plasma metabolomic profiling. PMID:25956449

  14. Investigation of a substrate-specifying residue within Papaver somniferum and Catharanthus roseus aromatic amino acid decarboxylases.

    PubMed

    Torrens-Spence, Michael P; Lazear, Michael; von Guggenberg, Renee; Ding, Haizhen; Li, Jianyong

    2014-10-01

    Plant aromatic amino acid decarboxylases (AAADs) catalyze the decarboxylation of aromatic amino acids with either benzene or indole rings. Because the substrate selectivity of AAADs is intimately related to their physiological functions, primary sequence data and their differentiation could provide significant physiological insights. However, due to general high sequence identity, plant AAAD substrate specificities have been difficult to identify through primary sequence comparison. In this study, bioinformatic approaches were utilized to identify several active site residues within plant AAAD enzymes that may impact substrate specificity. Next a Papaver somniferum tyrosine decarboxylase (TyDC) was selected as a model to verify our putative substrate-dictating residues through mutation. Results indicated that mutagenesis of serine 372 to glycine enables the P. somniferum TyDC to use 5-hydroxytryptophan as a substrate, and reduces the enzyme activity toward 3,4-dihydroxy-L-phenylalanine (dopa). Additionally, the reverse mutation in a Catharanthus roseus tryptophan decarboxylase (TDC) enables the mutant enzyme to utilize tyrosine and dopa as substrates with a reduced affinity toward tryptophan. Molecular modeling and molecular docking of the P. somniferum TyDC and the C. roseus TDC enzymes provided a structural basis to explain alterations in substrate specificity. Identification of an active site residue that impacts substrate selectivity produces a primary sequence identifier that may help differentiate the indolic and phenolic substrate specificities of individual plant AAADs. PMID:25107664

  15. Expression of the neurotransmitter-synthesizing enzyme glutamic acid decarboxylase in male germ cells.

    PubMed Central

    Persson, H; Pelto-Huikko, M; Metsis, M; Söder, O; Brene, S; Skog, S; Hökfelt, T; Ritzén, E M

    1990-01-01

    The gene encoding glutamic acid decarboxylase (GAD), the key enzyme in the synthesis of the inhibitory neurotransmitter gamma-aminobutyric acid, is shown to be expressed in the testis of several different species. Nucleotide sequence analysis of a cDNA clone isolated from the human testis confirmed the presence of GAD mRNA in the testis. The major GAD mRNA in the testis was 2.5 kilobases. Smaller amounts of a 3.7-kilobase mRNA with the same size as GAD mRNA in the brain was also detected in the testis. In situ hybridization using a GAD-specific probe revealed GAD mRNA expressing spermatocytes and spermatids located in the middle part of rat seminiferous tubules. Studies on the ontogeny of GAD mRNA expression showed low levels of GAD mRNA in testes of prepubertal rats, with increasing levels as sexual maturation is reached, compatible with GAD mRNA expression in germ cells. In agreement with this, fractionation of cells from the rat seminiferous epithelium followed by Northern (RNA) blot analysis showed the highest levels of GAD mRNA associated with spermatocytes and spermatids. Evidence for the presence of GAD protein in the rat testis was obtained from the demonstration of GAD-like immunoreactivity in seminiferous tubules, predominantly at a position where spermatids and spermatozoa are found. Furthermore, GAD-like immunoreactivity was seen in the midpiece of ejaculated human spermatozoa, the part that is responsible for generating energy for spermatozoan motility. Images PMID:1697032

  16. Role of UDP-Glucuronic Acid Decarboxylase in Xylan Biosynthesis in Arabidopsis.

    PubMed

    Kuang, Beiqing; Zhao, Xianhai; Zhou, Chun; Zeng, Wei; Ren, Junli; Ebert, Berit; Beahan, Cherie T; Deng, Xiaomei; Zeng, Qingyin; Zhou, Gongke; Doblin, Monika S; Heazlewood, Joshua L; Bacic, Antony; Chen, Xiaoyang; Wu, Ai-Min

    2016-08-01

    UDP-xylose (UDP-Xyl) is the Xyl donor used in the synthesis of major plant cell-wall polysaccharides such as xylan (as a backbone-chain monosaccharide) and xyloglucan (as a branching monosaccharide). The biosynthesis of UDP-Xyl from UDP-glucuronic acid (UDP-GlcA) is irreversibly catalyzed by UDP-glucuronic acid decarboxylase (UXS). Until now, little has been known about the physiological roles of UXS in plants. Here, we report that AtUXS1, AtUXS2, and AtUXS4 are located in the Golgi apparatus whereas AtUXS3, AtUXS5, and AtUXS6 are located in the cytosol. Although all six single AtUXS T-DNA mutants and the uxs1 usx2 uxs4 triple mutant show no obvious phenotype, the uxs3 uxs5 uxs6 triple mutant has an irregular xylem phenotype. Monosaccharide analysis showed that Xyl levels decreased in uxs3 uxs5 uxs6 and linkage analysis confirmed that the xylan content in uxs3 xus5 uxs6 declined, indicating that UDP-Xyl from cytosol AtUXS participates in xylan synthesis. Gel-permeation chromatography showed that the molecular weight of non-cellulosic polysaccharides in the triple mutants, mainly composed of xylans, is lower than that in the wild type, suggesting an effect on the elongation of the xylan backbone. Upon saccharification treatment stems of the uxs3 uxs5 uxs6 triple mutants released monosaccharides with a higher efficiency than those of the wild type. Taken together, our results indicate that the cytosol UXS plays a more important role than the Golgi-localized UXS in xylan biosynthesis. PMID:27179920

  17. [Neurochemical study of effects of the new anxiolytic drugs afobazol and ladasten on the synthesis and metabolism of monoamines and their metabolites in the brain structures of Wistar rat on the model of monoamine synthesis blockade induced by aromatic amino acid decarboxylase inhibitor NSD-1015].

    PubMed

    Davydova, A I; Klodt, P M; Kudrin, V S; Kuznetsova, E A; Narkevich, V B

    2010-03-01

    Results of a neurochemical study of the effects of the new anxiolytic drugs afobazole and ladasten on the synthesis and metabolism of monoamines and their metabolites determined by HPLC on the model of monoamine synthesis blockade induced by NSD-1015 (aromatic L-amino acid decarboxylase) in the brain structures of Wistar rats are reported. A decrease in the levels of DOPAC in hypothalamus and HVA in striatum after afobazole injection may be evidence of an inhibitory action of this drug on the activity of monoamine oxidase (MAO-A), which is the main enzyme involved in dopamine biodegradation. Afobazole was also found to increase the content of serotonin (5-HT) as well as its precursor (5-OTP) and its main metabolite (5-HIAA) in hypothalamus by up to 50, 60 and 50%, respectively, which confirms a hypothesis that this anxiolytic drug can modulate the activity of tryptophan hydroxylase (5-OTP synthesis enzyme). In contrast to afobazole, ladasten demonstrated the ability to increase the level of L-DOPA (a dopamine precursor) in virtually all functional structures of the brain (except for hippocamp), which may support the hypothesis suggestion concerning a predominant action of this drug on the activity of tyrosine hydroxylase. Ladasten exhibited selectivity with respect to the dopaminergic system and affected only parameters of the dopamine metabolism, in particular, by increasing the HVA content in nucleus accumbens and decreasing it in the hypothalamus. The drug also affected the dopamine turnover parameters, producing an increase in both HVA/dopamine ratio in nucleus accumbens and DOPAC/dopamine ratio in hippocamp. PMID:20408420

  18. Histidine decarboxylase and urinary methylimidazoleacetic acid in gastric neuroendocrine cells and tumours

    PubMed Central

    Tsolakis, Apostolos V; Grimelius, Lars; Granerus, Göran; Stridsberg, Mats; Falkmer, Sture E; Janson, Eva T

    2015-01-01

    AIM: To study histidine decarboxylase (HDC) expression in normal and neoplastic gastric neuroendocrine cells in relationship to the main histamine metabolite. METHODS: Control tissues from fundus (n = 3) and corpus (n = 3) mucosa of six patients undergoing operations for gastric adenocarcinoma, biopsy and/or gastric surgical specimens from 64 patients with primary gastric neuroendocrine tumours (GNETs), as well as metastases from 22 of these patients, were investigated using conventional immunohistochemistry and double immunofluorescence with commercial antibodies vs vesicular monoamine transporter 2 (VMAT-2), HDC and ghrelin. The urinary excretion of the main histamine metabolite methylimidazoleacetic acid (U-MeImAA) was determined using high-performance liquid chromatography in 27 of the 64 patients. RESULTS: In the gastric mucosa of the control tissues, co-localization studies identified neuroendocrine cells that showed immunoreactivity only to VMAT-2 and others with reactivity only to HDC. A third cell population co-expressed both antigens. There was no co-expression of HDC and ghrelin. Similar results were obtained in the foci of neuroendocrine cell hyperplasia associated with chronic atrophic gastritis type A and also in the tumours. The relative incidence of the three aforementioned markers varied in the tumours that were examined using conventional immunohistochemistry. All of these GNETs revealed both VMAT-2 and HDC immunoreactivity, and their metastases showed an immunohistochemical pattern and frequency similar to that of their primary tumours. In four patients, increased U-MeImAA excretion was detected, but only two of the patients exhibited related endocrine symptoms. CONCLUSION: Human enterochromaffin-like cells appear to partially co-express VMAT-2 and HDC. Co-expression of VMAT-2 and HDC might be required for increased histamine production in patients with GNETs. PMID:26715806

  19. Refractory status epilepticus and glutamic acid decarboxylase antibodies in adults: presentation, treatment and outcomes.

    PubMed

    Khawaja, Ayaz M; Vines, Brannon L; Miller, David W; Szaflarski, Jerzy P; Amara, Amy W

    2016-03-01

    Glutamic acid decarboxylase antibodies (GAD-Abs) have been implicated in refractory epilepsy. The association with refractory status epilepticus in adults has been rarely described. We discuss our experience in managing three adult patients who presented with refractory status epilepticus associated with GAD-Abs. Case series with retrospective chart and literature review. Three patients without pre-existing epilepsy who presented to our institution with generalized seizures between 2013 and 2014 were identified. Seizures proved refractory to first and second-line therapies and persisted beyond 24 hours. Patient 1 was a 22-year-old female who had elevated serum GAD-Ab titres at 0.49 mmol/l (normal: <0.02) and was treated with multiple immuno- and chemotherapies, with eventual partial seizure control. Patient 2 was a 61-year-old black female whose serum GAD-Ab titre was 0.08 mmol/l. EEG showed persistent generalized periodic discharges despite maximized therapy with anticonvulsants but no immunotherapy, resulting in withdrawal of care and discharge to nursing home. Patient 3 was a 50-year-old black female whose serum GAD-Ab titre was 0.08 mmol/l, and was discovered to have pulmonary sarcoidosis. Treatment with steroids and intravenous immunoglobulin resulted in seizure resolution. Due to the responsiveness to immunotherapy, there may be an association between GAD-Abs and refractory seizures, including refractory status epilepticus. Causation cannot be established since GAD-Abs may be elevated secondary to concurrent autoimmune diseases or formed de novo in response to GAD antigen exposure by neuronal injury. Based on this report and available literature, there may be a role for immuno- and chemotherapy in the management of refractory status epilepticus associated with GAD-Abs. PMID:26878120

  20. Structure of PA4019, a putative aromatic acid decarboxylase from Pseudomonas aeruginosa

    PubMed Central

    Kopec, Jolanta; Schnell, Robert; Schneider, Gunter

    2011-01-01

    The ubiX gene (PA4019) of Pseudomonas aeruginosa has been annotated as encoding a putative 3-octaprenyl-4-hydroxybenzoate decarboxylase from the ubiquinone-biosynthesis pathway. Based on a transposon mutagenesis screen, this gene was also implicated as being essential for the survival of this organism. The crystal structure of recombinant UbiX determined to 1.5 Å resolution showed that the protein belongs to the superfamily of homo-oligomeric flavine-containing cysteine decarboxylases. The enzyme assembles into a dodecamer with 23 point symmetry. The subunit displays a typical Rossmann fold and contains one FMN molecule bound at the interface between two subunits. PMID:22102023

  1. 1-METHYL-4-PHENYL-1,2,3,6-TETRAHYDROPYRIDINE (MPTP)-INDUCED ASTROGLIOSIS DOES NOT REQUIRE ACTIVATION OF ORNITHINE DECARBOXYLASE

    EPA Science Inventory

    Mechanical injury to the brain results in enhanced immunostaining for glial fibrillary acidic protein (GFAP) that is markedly inhibited by difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase. n the current study, systemic exposure of mice to the d...

  2. Structural Basis of Enzymatic Activity for the Ferulic Acid Decarboxylase (FADase) from Enterobacter sp. Px6-4

    PubMed Central

    Liang, Lianming; Sun, Yuna; Huang, Jingwen; Li, Xuemei; Cao, Yi; Meng, Zhaohui; Zhang, Ke-Qin

    2011-01-01

    Microbial ferulic acid decarboxylase (FADase) catalyzes the transformation of ferulic acid to 4-hydroxy-3-methoxystyrene (4-vinylguaiacol) via non-oxidative decarboxylation. Here we report the crystal structures of the Enterobacter sp. Px6-4 FADase and the enzyme in complex with substrate analogues. Our analyses revealed that FADase possessed a half-opened bottom β-barrel with the catalytic pocket located between the middle of the core β-barrel and the helical bottom. Its structure shared a high degree of similarity with members of the phenolic acid decarboxylase (PAD) superfamily. Structural analysis revealed that FADase catalyzed reactions by an “open-closed” mechanism involving a pocket of 8×8×15 Å dimension on the surface of the enzyme. The active pocket could directly contact the solvent and allow the substrate to enter when induced by substrate analogues. Site-directed mutagenesis showed that the E134A mutation decreased the enzyme activity by more than 60%, and Y21A and Y27A mutations abolished the enzyme activity completely. The combined structural and mutagenesis results suggest that during decarboxylation of ferulic acid by FADase, Trp25 and Tyr27 are required for the entering and proper orientation of the substrate while Glu134 and Asn23 participate in proton transfer. PMID:21283705

  3. Two UDP-glucuronic acid decarboxylases involved in the biosynthesis of a bacterial exopolysaccharide in Paenibacillus elgii.

    PubMed

    Li, Ou; Qian, Chao-Dong; Zheng, Dao-Qiong; Wang, Pin-Mei; Liu, Yu; Jiang, Xin-Hang; Wu, Xue-Chang

    2015-04-01

    Xylose is described as a component of bacterial exopolysaccharides in only a limited number of bacterial strains. A bacterial strain, Paenibacillus elgii, B69 was shown to be efficient in producing a xylose-containing exopolysaccharide. Sequence analysis was performed to identify the genes encoding the uridine diphosphate (UDP)-glucuronic acid decarboxylase required for the synthesis of UDP-xylose, the precursor of the exopolysaccharide. Two sequences, designated as Peuxs1 and Peuxs2, were found as the candidate genes for such enzymes. The activities of the UDP-glucuronic acid decarboxylases were proven by heterologous expression and real-time nuclear magnetic resonance analysis. The intracellular activity and effect of these genes on the synthesis of exopolysaccharide were further investigated by developing a thymidylate synthase based knockout system. This system was used to substitute the conventional antibiotic resistance gene system in P. elgii, a natural multi-antibiotic resistant strain. Results of intracellular nucleotide sugar analysis showed that the intracellular UDP-xylose and UDP-glucuronic acid levels were affected in Peuxs1 or Peuxs2 knockout strains. The knockout of either Peuxs1 or Peuxs2 reduced the polysaccharide production and changed the monosaccharide ratio. No polysaccharide was found in the Peuxs1/Peuxs2 double knockout strain. Our results show that P. elgii can be efficient in forming UDP-xylose, which is then used for the synthesis of xylose-containing exopolysaccharide. PMID:25573472

  4. Possible role for glutamic acid decarboxylase in fibromyalgia symptoms: a conceptual model for chronic pain.

    PubMed

    Fitzgerald, Caris T; Carter, Lawrence P

    2011-09-01

    Fibromyalgia (FM) is a condition of chronic generalized musculoskeletal pain that is thought to be a disorder of central pain sensitization. A number of neurotransmitters in the ascending and descending pain pathways have been implicated in FM including glutamate and GABA. Glutamic acid decarboxylase (GAD) is the rate-limiting enzyme in the conversion of glutamate to GABA and decreased expression or activity of this enzyme could result in an imbalance of excitatory and inhibitory neurotransmission in the ascending and descending pain pathways. Specifically, the expression and activity of the predominant isoform of GAD (GAD65) is influenced by several factors that are associated with FM such as female sex, poor diet, obesity, sedentary lifestyle, and stress. We hypothesize that decreased GAD expression and/or activity plays a role in the development and exacerbation of FM leading to impairments in the three common domains of FM symptomatology: increased pain (hyperalgesia and allodynia), disrupted sleep, and disturbances in mood (anxiety and depression). There are several lines of evidence that appear to support a role of GAD in FM. First, the defining symptom of FM is pain and GAD65 knockout mice have been shown to exhibit supraspinal hyperalgesia. Second, GAD has been implicated in disorders of muscle stiffness and rigidity and morning stiffness is a common symptom of FM. Third, stress, depression, and anxiety, which are often comorbid with FM, decrease GAD activity. Fourth, FM is associated with poor sleep, specifically disrupted non-rapid eye movement (NREM) sleep, and the pharmacological induction of NREM sleep is associated with the activation of GAD-containing neurons in the preoptic hypothalamus. Fifth, FM is more commonly diagnosed in women than men and the activity of GAD is reduced by low levels of its cofactor pyroxidine, which is less well-absorbed by women and can be further lowered by diet, tobacco, and alcohol intake. Sixth, FM patients tend to be

  5. Cholera Toxin B Subunit Linked to Glutamic Acid Decarboxylase Suppresses Dendritic Cell Maturation and Function

    PubMed Central

    Odumosu, Oludare; Nicholas, Dequina; Payne, Kimberly; Langridge, William

    2012-01-01

    Dendritic cells are the largest population of antigen presenting cells in the body. One of their main functions is to regulate the delicate balance between immunity and tolerance responsible for maintenance of immunological homeostasis. Disruption of this delicate balance often results in chronic inflammation responsible for initiation of organ specific autoimmune diseases such as rheumatoid arthritis, multiple sclerosis and type I diabetes. The cholera toxin B subunit (CTB) is a weak mucosal adjuvant known for its ability to stimulate immunity to antigenic proteins. However, conjugation of CTB to many autoantigens can induce immunological tolerance resulting in suppression of autoimmunity. In this study, we examined whether linkage of CTB to a 5 kDa C-terminal protein fragment of the major diabetes autoantigen glutamic acid decarboxylase (GAD35), can block dendritic cell (DC) functions such as biosynthesis of co-stimulatory factor proteins CD86, CD83, CD80 and CD40 and secretion of inflammatory cytokines. The results of human umbilical cord blood monocyte-derived DC - GAD35 autoantigen incubation experiments showed that inoculation of immature DCs (iDCs), with CTB-GAD35 protein dramatically suppressed levels of CD86, CD83, CD80 and CD40 co-stimulatory factor protein biosynthesis in comparison with GAD35 alone inoculated iDCs. Surprisingly, incubation of iDCs in the presence of the CTB-autoantigen and the strong immunostimulatory molecules PMA and Ionomycin revealed that CTB-GAD35 was capable of arresting PMA + Ionomycin induced DC maturation. Consistant with this finding, CTB-GAD35 mediated suppression of DC maturation was accompanied by a dramatic decrease in the secretion of the pro-inflammatory cytokines IL-12/23p40 and IL-6 and a significant increase in secretion of the immunosuppressive cytokine IL-10. Taken together, our experimental data suggest that linkage of the weak adjuvant CTB to the dominant type 1 diabetes autoantigen GAD strongly inhibits DC

  6. Glutamate Decarboxylase-Dependent Acid Resistance in Brucella spp.: Distribution and Contribution to Fitness under Extremely Acidic Conditions

    PubMed Central

    Damiano, Maria Alessandra; Bastianelli, Daniela; Al Dahouk, Sascha; Köhler, Stephan; Cloeckaert, Axel

    2014-01-01

    Brucella is an expanding genus of major zoonotic pathogens, including at least 10 genetically very close species occupying a wide range of niches from soil to wildlife, livestock, and humans. Recently, we have shown that in the new species Brucella microti, the glutamate decarboxylase (Gad)-dependent system (GAD system) contributes to survival at a pH of 2.5 and also to infection in mice by the oral route. In order to study the functionality of the GAD system in the genus Brucella, 47 isolates, representative of all known species and strains of this genus, and 16 strains of the closest neighbor genus, Ochrobactrum, were studied using microbiological, biochemical, and genetic approaches. In agreement with the genome sequences, the GAD system of classical species was not functional, unlike that of most strains of Brucella ceti, Brucella pinnipedialis, and newly described species (B. microti, Brucella inopinata BO1, B. inopinata-like BO2, and Brucella sp. isolated from bullfrogs). In the presence of glutamate, these species were more acid resistant in vitro than classical terrestrial brucellae. Expression in trans of the gad locus from representative Brucella species in the Escherichia coli MG1655 mutant strain lacking the GAD system restored the acid-resistant phenotype. The highly conserved GAD system of the newly described or atypical Brucella species may play an important role in their adaptation to acidic external and host environments. Furthermore, the GAD phenotype was shown to be a useful diagnostic tool to distinguish these latter Brucella strains from Ochrobactrum and from classical terrestrial pathogenic Brucella species, which are GAD negative. PMID:25381237

  7. A rare cause of severe diarrhoea diagnosed by urine metabolic screening: aromatic L-amino acid decarboxylase deficiency.

    PubMed

    Lee, L K; Cheung, K M; Cheng, W W; Ko, C H; Lee, Hencher H C; Ching, C K; Mak, Chloe M

    2014-04-01

    A 15-year-old Chinese male with infantile-onset hypotonia, developmental delay, ptosis, and oculogyric episodes presented with a history of chronic diarrhoea since the age of 5 years. At presentation, he had an exacerbation of diarrhoeal symptoms resulting in dehydration and malnutrition with a concurrent severe chest infection. In view of his infantile-onset hypotonia, oculogyric crises, and protracted diarrhoea, an autonomic disturbance related to neurotransmitters was suspected. Urine organic acid profiling was compatible with aromatic L-amino acid decarboxylase deficiency. The diagnosis was confirmed based on cerebrospinal fluid analysis and genetic mutation analysis. The patient was treated with a combination of bromocriptine, selegiline, and pyridoxine; a satisfactory reduction in diarrhoea ensued. Our report highlights the importance of urine organic acid screening in infantile-onset hypotonia, especially when accompanied by oculogyric crises, and severe diarrhoea which could manifest as a result of autonomic disturbance. PMID:24714172

  8. An organic solvent-tolerant phenolic acid decarboxylase from Bacillus licheniformis for the efficient bioconversion of hydroxycinnamic acids to vinyl phenol derivatives.

    PubMed

    Hu, Hongfei; Li, Lulu; Ding, Shaojun

    2015-06-01

    A new phenolic acid decarboxylase gene (blpad) from Bacillus licheniformis was cloned and overexpressed in Escherichia coli. The full-length blpad encodes a 166-amino acid polypeptide with a predicted molecular mass and pI of 19,521 Da and 5.02, respectively. The recombinant BLPAD displayed maximum activity at 37 °C and pH 6.0. This enzyme possesses a broad substrate specificity and is able to decarboxylate p-coumaric, ferulic, caffeic, and sinapic acids at the relative ratios of specific activities 100:74.59:34.41:0.29. Kinetic constant K m values toward p-coumaric, ferulic, caffeic, and sinapic acids were 1.64, 1.55, 1.93, and 2.45 mM, and V max values were 268.43, 216.80, 119.07, and 0.78 U mg(-1), respectively. In comparison with other phenolic acid decarboxylases, BLPAD exhibited remarkable organic solvent tolerance and good thermal stability. BLPAD showed excellent catalytic performance in biphasic organic/aqueous systems and efficiently converted p-coumaric and ferulic acids into 4-vinylphenol and 4-vinylguaiacol. At 500 mM of p-coumaric and ferulic acids, the recombinant BLPAD produced a total 60.63 g l(-1) 4-vinylphenol and 58.30 g l(-1) 4-vinylguaiacol with the conversion yields 97.02 and 70.96 %, respectively. The low yield and product concentration are the crucial drawbacks to the practical bioproduction of vinyl phenol derivatives using phenolic acid decarboxylases. These unusual properties make BLPAD a desirable biocatalyst for commercial use in the bioconversion of hydroxycinnamic acids to vinyl phenol derivatives via enzymatic decarboxylation in a biphasic organic/aqueous reaction system. PMID:25547838

  9. Pyruvate decarboxylase catalyzes decarboxylation of branched-chain 2-oxo acids but is not essential for fusel alcohol production by Saccharomyces cerevisiae.

    PubMed

    ter Schure, E G; Flikweert, M T; van Dijken, J P; Pronk, J T; Verrips, C T

    1998-04-01

    The fusel alcohols 3-methyl-1-butanol, 2-methyl-1-butanol, and 2-methyl-propanol are important flavor compounds in yeast-derived food products and beverages. The formation of these compounds from branched-chain amino acids is generally assumed to occur via the Ehrlich pathway, which involves the concerted action of a branched-chain transaminase, a decarboxylase, and an alcohol dehydrogenase. Partially purified preparations of pyruvate decarboxylase (EC 4.1.1.1) have been reported to catalyze the decarboxylation of the branched-chain 2-oxo acids formed upon transamination of leucine, isoleucine, and valine. Indeed, in a coupled enzymatic assay with horse liver alcohol dehydrogenase, cell extracts of a wild-type Saccharomyces cerevisiae strain exhibited significant decarboxylation rates with these branched-chain 2-oxo acids. Decarboxylation of branched-chain 2-oxo acids was not detectable in cell extracts of an isogenic strain in which all three PDC genes had been disrupted. Experiments with cell extracts from S. cerevisiae mutants expressing a single PDC gene demonstrated that both PDC1- and PDC5-encoded isoenzymes can decarboxylate branched-chain 2-oxo acids. To investigate whether pyruvate decarboxylase is essential for fusel alcohol production by whole cells, wild-type S. cerevisiae and an isogenic pyruvate decarboxylase-negative strain were grown on ethanol with a mixture of leucine, isoleucine, and valine as the nitrogen source. Surprisingly, the three corresponding fusel alcohols were produced in both strains. This result proves that decarboxylation of branched-chain 2-oxo acids via pyruvate decarboxylase is not an essential step in fusel alcohol production. PMID:9546164

  10. Chemical fragmentation by o-iodosobenzoic acid of. cap alpha. -chain of histidine decarboxylase from Micrococcus sp. n. at tryptophan residues

    SciTech Connect

    Alekseeva, E.A.; Grebenshchikova, O.G.; Prozorovskii, V.N.

    1987-02-10

    The carboxymethylated ..cap alpha..-chain of histidine decarboxylase from Micrococcus sp. n., which contains four tryptophan residues, was cleaved by o-iodosobenzoic acid. Five fragments were isolated in homogeneous form by means of gel filtration on Sephadex, rechromatography, and high-voltage paper electrophoresis. The molecular weight, amino acid composition, and N-terminal amino acid sequence were determined for all the peptides isolated.

  11. The influence of the cell free solution of lactic acid bacteria on tyramine production by food borne-pathogens in tyrosine decarboxylase broth.

    PubMed

    Toy, Nurten; Özogul, Fatih; Özogul, Yesim

    2015-04-15

    The function of cell-free solutions (CFSs) of lactic acid bacteria (LAB) on tyramine and other biogenic amine production by different food borne-pathogens (FBPs) was investigated in tyrosine decarboxylase broth (TDB) using HPLC. Cell free solutions were prepared from four LAB strains. Two different concentrations which were 50% (5 ml CFS+5 ml medium/1:1) and 25% (2.5 ml CFS+7.5 ml medium/1:3) CFS and the control without CFS were prepared. Both concentration of CFS of Streptococcus thermophilus and 50% CFS of Pediococcus acidophilus inhibited tyramine production up to 98% by Salmonella paratyphi A. Tyramine production by Escherichia coli was also inhibited by 50% CFS of Lactococcus lactis subsp. lactis and 25% CFS of Leuconostoc lactis. subsp. cremoris. The inhibitor effect of 50% CFS of P. acidophilus was the highest on tyramine production (55%) by Listeria monocytogenes, following Lc. lactis subsp. lactis and Leuconostoc mesenteroides subsp. cremoris (20%) whilst 25% CFS of Leu. mes. subsp. cremoris and Lc. lactis subsp. lactis showed stimulator effects (160%). The stimulation effects of 50% CFS of S. thermophilus and Lc. lactis subsp. lactis were more than 70% by Staphylococcus aureus comparing to the control. CFS of LAB strains showed statistically inhibitor effect since lactic acid inhibited microbial growth, decreased pH quickly and reduced the formation of AMN and BAs. Consequently, in order to avoid the formation of high concentrations of biogenic amines in fermented food by bacteria, it is advisable to use CFS for food and food products. PMID:25465993

  12. Terminal Olefin (1-Alkene) Biosynthesis by a Novel P450 Fatty Acid Decarboxylase from Jeotgalicoccus Species ▿ †

    PubMed Central

    Rude, Mathew A.; Baron, Tarah S.; Brubaker, Shane; Alibhai, Murtaza; Del Cardayre, Stephen B.; Schirmer, Andreas

    2011-01-01

    Terminal olefins (1-alkenes) are natural products that have important industrial applications as both fuels and chemicals. However, their biosynthesis has been largely unexplored. We describe a group of bacteria, Jeotgalicoccus spp., which synthesize terminal olefins, in particular 18-methyl-1-nonadecene and 17-methyl-1-nonadecene. These olefins are derived from intermediates of fatty acid biosynthesis, and the key enzyme in Jeotgalicoccus sp. ATCC 8456 is a terminal olefin-forming fatty acid decarboxylase. This enzyme, Jeotgalicoccus sp. OleT (OleTJE), was identified by purification from cell lysates, and its encoding gene was identified from a draft genome sequence of Jeotgalicoccus sp. ATCC 8456 using reverse genetics. Heterologous expression of the identified gene conferred olefin biosynthesis to Escherichia coli. OleTJE is a P450 from the cyp152 family, which includes bacterial fatty acid hydroxylases. Some cyp152 P450 enzymes have the ability to decarboxylate and to hydroxylate fatty acids (in α- and/or β-position), suggesting a common reaction intermediate in their catalytic mechanism and specific structural determinants that favor one reaction over the other. The discovery of these terminal olefin-forming P450 enzymes represents a third biosynthetic pathway (in addition to alkane and long-chain olefin biosynthesis) to convert fatty acid intermediates into hydrocarbons. Olefin-forming fatty acid decarboxylation is a novel reaction that can now be added to the catalytic repertoire of the versatile cytochrome P450 enzyme family. PMID:21216900

  13. Cortical Gene Expression After a Conditional Knockout of 67 kDa Glutamic Acid Decarboxylase in Parvalbumin Neurons.

    PubMed

    Georgiev, Danko; Yoshihara, Toru; Kawabata, Rika; Matsubara, Takurou; Tsubomoto, Makoto; Minabe, Yoshio; Lewis, David A; Hashimoto, Takanori

    2016-07-01

    In the cortex of subjects with schizophrenia, expression of glutamic acid decarboxylase 67 (GAD67), the enzyme primarily responsible for cortical GABA synthesis, is reduced in the subset of GABA neurons that express parvalbumin (PV). This GAD67 deficit is accompanied by lower cortical levels of other GABA-associated transcripts, including GABA transporter-1, PV, brain-derived neurotrophic factor (BDNF), tropomyosin receptor kinase B, somatostatin, GABAA receptor α1 subunit, and KCNS3 potassium channel subunit mRNAs. In contrast, messenger RNA (mRNA) levels for glutamic acid decarboxylase 65 (GAD65), another enzyme for GABA synthesis, are not altered. We tested the hypothesis that this pattern of GABA-associated transcript levels is secondary to the GAD67 deficit in PV neurons by analyzing cortical levels of these GABA-associated mRNAs in mice with a PV neuron-specific GAD67 knockout. Using in situ hybridization, we found that none of the examined GABA-associated transcripts had lower cortical expression in the knockout mice. In contrast, PV, BDNF, KCNS3, and GAD65 mRNA levels were higher in the homozygous mice. In addition, our behavioral test battery failed to detect a change in sensorimotor gating or working memory, although the homozygous mice exhibited increased spontaneous activities. These findings suggest that reduced GAD67 expression in PV neurons is not an upstream cause of the lower levels of GABA-associated transcripts, or of the characteristic behaviors, in schizophrenia. In PV neuron-specific GAD67 knockout mice, increased levels of PV, BDNF, and KCNS3 mRNAs might be the consequence of increased neuronal activity secondary to lower GABA synthesis, whereas increased GAD65 mRNA might represent a compensatory response to increase GABA synthesis. PMID:26980143

  14. Gamma-aminobutyric acid production using immobilized glutamate decarboxylase followed by downstream processing with cation exchange chromatography.

    PubMed

    Lee, Seungwoon; Ahn, Jungoh; Kim, Yeon-Gu; Jung, Joon-Ki; Lee, Hongweon; Lee, Eun Gyo

    2013-01-01

    We have developed a gamma-aminobutyric acid (GABA) production technique using his-tag mediated immobilization of Escherichia coli-derived glutamate decarboxylase (GAD), an enzyme that catalyzes the conversion of glutamate to GABA. The GAD was obtained at 1.43 g/L from GAD-overexpressed E. coli fermentation and consisted of 59.7% monomer, 29.2% dimer and 2.3% tetramer with a 97.6% soluble form of the total GAD. The harvested GAD was immobilized to metal affinity gel with an immobilization yield of 92%. Based on an investigation of specific enzyme activity and reaction characteristics, glutamic acid (GA) was chosen over monosodium glutamate (MSG) as a substrate for immobilized GAD, resulting in conversion of 2.17 M GABA in a 1 L reactor within 100 min. The immobilized enzymes retained 58.1% of their initial activities after ten consecutive uses. By using cation exchange chromatography followed by enzymatic conversion, GABA was separated from the residual substrate and leached GAD. As a consequence, the glutamic acid was mostly removed with no detectable GAD, while 91.2% of GABA was yielded in the purification step. PMID:23322022

  15. Identification of the Enterobacteriaceae in Montasio cheese and assessment of their amino acid decarboxylase activity.

    PubMed

    Maifreni, Michela; Frigo, Francesca; Bartolomeoli, Ingrid; Innocente, Nadia; Biasutti, Marialuisa; Marino, Marilena

    2013-02-01

    The aim of the study was to identify the species of Enterobacteriaceae present in Montasio cheese and to assess their potential to produce biogenic amines. Plate count methods and an Enterobacterial Repetitive Intergenic Consensus Polymerase Chain Reaction (ERIC-PCR) approach, combined with 16S rDNA sequencing, were used to investigate the Enterobacteriaceae community present during the cheesemaking and ripening of 6 batches of Montasio cheese. Additionally, the potential decarboxylation abilities of selected bacterial isolates were qualitatively and quantitatively assessed against tyrosine, histidine, ornithine and lysine. The most predominant species detected during cheese manufacturing and ripening were Enterobacter cloacae, Escherichia coli and Hafnia alvei. The non-limiting physico-chemical conditions (pH, NaCl% and a(w)) during ripening were probably the cause of the presence of detectable levels of Enterobacteriaceae up to 120 d of ripening. The HPLC test showed that cadaverine and putrescine were the amines produced in higher amounts by almost all isolates, indicating that the presence of these amines in cheese can be linked to the presence of high counts of Enterobacteriaceae. 44 isolates produced low amounts of histamine (<300 ppm), and four isolates produced more than 1000 ppm of this amine. Only 9 isolates, belonging to the species Citrobacter freundii, Esch. coli and Raoultella ornithinolytica, appeared to produce tyramine. These data provided new information regarding the decarboxylase activity of some Enterobacteriaceae species, including Pantoea agglomerans, Esch. fergusonii and R. ornithinolytica. PMID:23298547

  16. Biochemical and spectroscopic properties of Brucella microti glutamate decarboxylase, a key component of the glutamate-dependent acid resistance system

    PubMed Central

    Grassini, Gaia; Pennacchietti, Eugenia; Cappadocio, Francesca; Occhialini, Alessandra; De Biase, Daniela

    2015-01-01

    In orally acquired bacteria, the ability to counteract extreme acid stress (pH ⩽ 2.5) ensures survival during transit through the animal host stomach. In several neutralophilic bacteria, the glutamate-dependent acid resistance system (GDAR) is the most efficient molecular system in conferring protection from acid stress. In Escherichia coli its structural components are either of the two glutamate decarboxylase isoforms (GadA, GadB) and the antiporter, GadC, which imports glutamate and exports γ-aminobutyrate, the decarboxylation product. The system works by consuming protons intracellularly, as part of the decarboxylation reaction, and exporting positive charges via the antiporter. Herein, biochemical and spectroscopic properties of GadB from Brucella microti (BmGadB), a Brucella species which possesses GDAR, are described. B. microti belongs to a group of lately described and atypical brucellae that possess functional gadB and gadC genes, unlike the most well-known “classical” Brucella species, which include important human pathogens. BmGadB is hexameric at acidic pH. The pH-dependent spectroscopic properties and activity profile, combined with in silico sequence comparison with E. coli GadB (EcGadB), suggest that BmGadB has the necessary structural requirements for the binding of activating chloride ions at acidic pH and for the closure of its active site at neutral pH. On the contrary, cellular localization analysis, corroborated by sequence inspection, suggests that BmGadB does not undergo membrane recruitment at acidic pH, which was observed in EcGadB. The comparison of GadB from evolutionary distant microorganisms suggests that for this enzyme to be functional in GDAR some structural features must be preserved. PMID:25853037

  17. Disruption of pknG enhances production of gamma-aminobutyric acid by Corynebacterium glutamicum expressing glutamate decarboxylase

    PubMed Central

    2014-01-01

    Gamma-aminobutyric acid (GABA), a building block of the biodegradable plastic polyamide 4, is synthesized from glucose by Corynebacterium glutamicum that expresses Escherichia coli glutamate decarboxylase (GAD) B encoded by gadB. This strain was engineered to produce GABA more efficiently from biomass-derived sugars. To enhance GABA production further by increasing the intracellular concentration of its precursor glutamate, we focused on engineering pknG (encoding serine/threonine protein kinase G), which controls the activity of 2-oxoglutarate dehydrogenase (Odh) in the tricarboxylic acid cycle branch point leading to glutamate synthesis. We succeeded in expressing GadB in a C. glutamicum strain harboring a deletion of pknG. C. glutamicum strains GAD and GAD ∆pknG were cultured in GP2 medium containing 100 g L−1 glucose and 0.1 mM pyridoxal 5′-phosphate. Strain GAD∆pknG produced 31.1 ± 0.41 g L−1 (0.259 g L−1 h−1) of GABA in 120 hours, representing a 2.29-fold higher level compared with GAD. The production yield of GABA from glucose by GAD∆pknG reached 0.893 mol mol−1. PMID:24949255

  18. From Protease to Decarboxylase: THE MOLECULAR METAMORPHOSIS OF PHOSPHATIDYLSERINE DECARBOXYLASE.

    PubMed

    Choi, Jae-Yeon; Duraisingh, Manoj T; Marti, Matthias; Ben Mamoun, Choukri; Voelker, Dennis R

    2015-04-24

    Phosphatidylserine decarboxylase (PSDs) play a central role in the synthesis of phosphatidylethanolamine in numerous species of prokaryotes and eukaryotes. PSDs are unusual decarboxylase containing a pyruvoyl prosthetic group within the active site. The covalently attached pyruvoyl moiety is formed in a concerted reaction when the PSD proenzyme undergoes an endoproteolytic cleavage into a large β-subunit, and a smaller α-subunit, which harbors the prosthetic group at its N terminus. The mechanism of PSD proenzyme cleavage has long been unclear. Using a coupled in vitro transcription/translation system with the soluble Plasmodium knowlesi enzyme (PkPSD), we demonstrate that the post-translational processing is inhibited by the serine protease inhibitor, phenylmethylsulfonyl fluoride. Comparison of PSD sequences across multiple phyla reveals a uniquely conserved aspartic acid within an FFXRX6RX12PXD motif, two uniquely conserved histidine residues within a PXXYHXXHXP motif, and a uniquely conserved serine residue within a GS(S/T) motif, suggesting that PSDs belong to the D-H-S serine protease family. The function of the conserved D-H-S residues was probed using site-directed mutagenesis of PkPSD. The results from these mutagenesis experiments reveal that Asp-139, His-198, and Ser-308 are all essential for endoproteolytic processing of PkPSD, which occurs in cis. In addition, within the GS(S/T) motif found in all PSDs, the Gly-307 residue is also essential, but the Ser/Thr-309 is non-essential. These results define the mechanism whereby PSDs begin their biochemical existence as proteases that execute one autoendoproteolytic cleavage reaction to give rise to a mature PSD harboring a pyruvoyl prosthetic group. PMID:25724650

  19. Knockout of the p-Coumarate Decarboxylase Gene from Lactobacillus plantarum Reveals the Existence of Two Other Inducible Enzymatic Activities Involved in Phenolic Acid Metabolism

    PubMed Central

    Barthelmebs, Lise; Divies, Charles; Cavin, Jean-François

    2000-01-01

    Lactobacillus plantarum NC8 contains a pdc gene coding for p-coumaric acid decarboxylase activity (PDC). A food grade mutant, designated LPD1, in which the chromosomal pdc gene was replaced with the deleted pdc gene copy, was obtained by a two-step homologous recombination process using an unstable replicative vector. The LPD1 mutant strain remained able to weakly metabolize p-coumaric and ferulic acids into vinyl derivatives or into substituted phenyl propionic acids. We have shown that L. plantarum has a second acid phenol decarboxylase enzyme, better induced with ferulic acid than with p-coumaric acid, which also displays inducible acid phenol reductase activity that is mostly active when glucose is added. Those two enzymatic activities are in competition for p-coumaric and ferulic acid degradation, and the ratio of the corresponding derivatives depends on induction conditions. Moreover, PDC appeared to decarboxylate ferulic acid in vitro with a specific activity of about 10 nmol · min−1 · mg−1 in the presence of ammonium sulfate. Finally, PDC activity was shown to confer a selective advantage on LPNC8 grown in acidic media supplemented with p-coumaric acid, compared to the LPD1 mutant devoid of PDC activity. PMID:10919793

  20. Heterocyclics as corrosion inhibitors for acid media

    SciTech Connect

    Ajmal, M.; Khan, M.A.W.; Ahmad, S.; Quraishi, M.A.

    1996-12-01

    The available literature on the use of heterocyclic compounds as corrosion inhibitors in acid media has been reviewed. It has been noted that the workers in this field have either used sulfur or nitrogen containing heterocyclic compounds for studying inhibition action. The authors have synthesized compounds containing sulfur and nitrogen both in the same ring and studied their inhibition action in acid media. These compounds were found to be better inhibitors than those containing either atoms alone.

  1. Overexpression and optimization of glutamate decarboxylase in Lactobacillus plantarum Taj-Apis362 for high gamma-aminobutyric acid production

    PubMed Central

    Tajabadi, Naser; Baradaran, Ali; Ebrahimpour, Afshin; Rahim, Raha A; Bakar, Fatimah A; Manap, Mohd Yazid A; Mohammed, Abdulkarim S; Saari, Nazamid

    2015-01-01

    Gamma-aminobutyric acid (GABA) is an important bioactive compound biosynthesized by microorganisms through decarboxylation of glutamate by glutamate decarboxylase (GAD). In this study, a full-length GAD gene was obtained by cloning the template deoxyribonucleic acid to pTZ57R/T vector. The open reading frame of the GAD gene showed the cloned gene was composed of 1410 nucleotides and encoded a 469 amino acids protein. To improve the GABA-production, the GAD gene was cloned into pMG36e-LbGAD, and then expressed in Lactobacillus plantarum Taj-Apis362 cells. The overexpression was confirmed by SDS-PAGE and GAD activity, showing a 53 KDa protein with the enzyme activity increased by sevenfold compared with the original GAD activity. The optimal fermentation conditions for GABA production established using response surface methodology were at glutamic acid concentration of 497.973 mM, temperature 36°C, pH 5.31 and time 60 h. Under the conditions, maximum GABA concentration obtained (11.09 mM) was comparable with the predicted value by the model at 11.23 mM. To our knowledge, this is the first report of successful cloning (clone-back) and overexpression of the LbGAD gene from L. plantarum to L. plantarum cells. The recombinant Lactobacillus could be used as a starter culture for direct incorporation into a food system during fermentation for production of GABA-rich products. PMID:25757029

  2. Overexpression and optimization of glutamate decarboxylase in Lactobacillus plantarum Taj-Apis362 for high gamma-aminobutyric acid production.

    PubMed

    Tajabadi, Naser; Baradaran, Ali; Ebrahimpour, Afshin; Rahim, Raha A; Bakar, Fatimah A; Manap, Mohd Yazid A; Mohammed, Abdulkarim S; Saari, Nazamid

    2015-07-01

    Gamma-aminobutyric acid (GABA) is an important bioactive compound biosynthesized by microorganisms through decarboxylation of glutamate by glutamate decarboxylase (GAD). In this study, a full-length GAD gene was obtained by cloning the template deoxyribonucleic acid to pTZ57R/T vector. The open reading frame of the GAD gene showed the cloned gene was composed of 1410 nucleotides and encoded a 469 amino acids protein. To improve the GABA-production, the GAD gene was cloned into pMG36e-LbGAD, and then expressed in Lactobacillus plantarum Taj-Apis362 cells. The overexpression was confirmed by SDS-PAGE and GAD activity, showing a 53 KDa protein with the enzyme activity increased by sevenfold compared with the original GAD activity. The optimal fermentation conditions for GABA production established using response surface methodology were at glutamic acid concentration of 497.973 mM, temperature 36°C, pH 5.31 and time 60 h. Under the conditions, maximum GABA concentration obtained (11.09 mM) was comparable with the predicted value by the model at 11.23 mM. To our knowledge, this is the first report of successful cloning (clone-back) and overexpression of the LbGAD gene from L. plantarum to L. plantarum cells. The recombinant Lactobacillus could be used as a starter culture for direct incorporation into a food system during fermentation for production of GABA-rich products. PMID:25757029

  3. Hydrogen peroxide-independent production of α-alkenes by OleTJE P450 fatty acid decarboxylase

    PubMed Central

    2014-01-01

    Background Cytochrome P450 OleTJE from Jeotgalicoccus sp. ATCC 8456, a new member of the CYP152 peroxygenase family, was recently found to catalyze the unusual decarboxylation of long-chain fatty acids to form α-alkenes using H2O2 as the sole electron and oxygen donor. Because aliphatic α-alkenes are important chemicals that can be used as biofuels to replace fossil fuels, or for making lubricants, polymers and detergents, studies on OleTJE fatty acid decarboxylase are significant and may lead to commercial production of biogenic α-alkenes in the future, which are renewable and more environmentally friendly than petroleum-derived equivalents. Results We report the H2O2-independent activity of OleTJE for the first time. In the presence of NADPH and O2, this P450 enzyme efficiently decarboxylates long-chain fatty acids (C12 to C20) in vitro when partnering with either the fused P450 reductase domain RhFRED from Rhodococcus sp. or the separate flavodoxin/flavodoxin reductase from Escherichia coli. In vivo, expression of OleTJE or OleTJE-RhFRED in different E. coli strains overproducing free fatty acids resulted in production of variant levels of multiple α-alkenes, with a highest total hydrocarbon titer of 97.6 mg·l-1. Conclusions The discovery of the H2O2-independent activity of OleTJE not only raises a number of fundamental questions on the monooxygenase-like mechanism of this peroxygenase, but also will direct the future metabolic engineering work toward improvement of O2/redox partner(s)/NADPH for overproduction of α-alkenes by OleTJE. PMID:24565055

  4. The selective conversion of glutamic acid in amino acid mixtures using glutamate decarboxylase--a means of separating amino acids for synthesizing biobased chemicals.

    PubMed

    Teng, Yinglai; Scott, Elinor L; Sanders, Johan P M

    2014-01-01

    Amino acids (AAs) derived from hydrolysis of protein rest streams are interesting feedstocks for the chemical industry due to their functionality. However, separation of AAs is required before they can be used for further applications. Electrodialysis may be applied to separate AAs, but its efficiency is limited when separating AAs with similar isoelectric points. To aid the separation, specific conversion of an AA to a useful product with different charge behavior to the remaining compounds is desired. Here the separation of L-aspartic acid (Asp) and L-glutamic acid (Glu) was studied. L-Glutamate α-decarboxylase (GAD, Type I, EC 4.1.1.15) was applied to specifically convert Glu into γ-aminobutyric acid (GABA). GABA has a different charge behavior from Asp therefore allowing a potential separation by electrodialysis. Competitive inhibition and reduced operational stability caused by Asp could be eliminated by maintaining a sufficiently high concentration of Glu. Immobilization of GAD does not reduce the enzyme's initial activity. However, the operational stability was slightly reduced. An initial study on the reaction operating in a continuous mode was performed using a column reactor packed with immobilized GAD. As the reaction mixture was only passed once through the reactor, the conversion of Glu was lower than expected. To complete the conversion of Glu, the stream containing Asp and unreacted Glu might be recirculated back to the reactor after GABA has been removed. Overall, the reaction by GAD is specific to Glu and can be applied to aid the electrodialysis separation of Asp and Glu. PMID:24616376

  5. Removal kinetics of antibodies against glutamic acid decarboxylase by various plasmapheresis modalities in the treatment of neurological disorders.

    PubMed

    Ohkubo, Atsushi; Okado, Tomokazu; Kurashima, Naoki; Maeda, Takuma; Miyamoto, Satoko; Nakamura, Ayako; Seshima, Hiroshi; Iimori, Soichiro; Sohara, Eisei; Uchida, Shinichi; Rai, Tatemitsu

    2014-06-01

    Plasmapheresis is one of the acute treatment modalities for neurological disorders associated with antibodies against glutamic acid decarboxylase (anti-GAD). However, there is little information about the removal kinetics of anti-GAD by various plasmapheresis modalities. Here, we investigated the removal rate of anti-GAD and fibrinogen (Fib) by immunoadsorption (IA), plasma exchange using a conventional plasma separator (OP-PE), and plasma exchange using a high cut-off selective membrane plasma separator (EC-PE) in two cases of anti-GAD-associated neurological diseases. In case 1, IA and OP-PE were used, and the percent reductions were as follows: anti-GAD: 38.2% and 69.1% and Fib: 67.7% and 68.2%, respectively. In case 2, OP-PE and EC-PE were used, and the percent reductions were as follows: anti-GAD: 65.8% and 48.5% and Fib: 68.5% and 19.8%, respectively. OP-PE could remove anti-GAD more efficiently than IA. Further, EC-PE could maintain coagulation factors such as Fib better than IA and OP-PE. It is important to select the appropriate plasmapheresis modality on the basis of the removal kinetics. PMID:24965288

  6. IGF2BP2 Alternative Variants Associated with Glutamic Acid Decarboxylase Antibodies Negative Diabetes in Malaysian Subjects

    PubMed Central

    Salem, Sameer D.; Saif-Ali, Riyadh; Ismail, Ikram S.; Al-Hamodi, Zaid; Poh, Rozaida; Muniandy, Sekaran

    2012-01-01

    Background The association of Insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) common variants (rs4402960 and rs1470579) with type 2 diabetes (T2D) has been performed in different populations. The aim of this study was to evaluate the association of alternative variants of IGF2BP2; rs6777038, rs16860234 and rs7651090 with glutamic acid decarboxylase antibodies (GADA) negative diabetes in Malaysian Subjects. Methods/Principal Findings IGF2BP2; rs6777038, rs16860234 and rs7651090 single nucleotide polymorphisms (SNPs) were genotyped in 1107 GADA negative diabetic patients and 620 control subjects of Asian from Malaysia. The additive genetic model adjusted for age, race, gender and BMI showed that alternative variants; rs6777038, rs16860234 and rs7651090 of IGF2BP2 associated with GADA negative diabetes (OR = 1.21; 1.36; 1.35, P = 0.03; 0.0004; 0.0002, respectively). In addition, the CCG haplotype and diplotype CCG-TCG increased the risk of diabetes (OR = 1.51, P = 0.01; OR = 2.36, P = 0.009, respectively). Conclusions/Significance IGF2BP2 alternative variants were associated with GADA negative diabetes. The IGF2BP2 haplotypes and diplotypes increased the risk of diabetes in Malaysian subject. PMID:23029108

  7. Pyridoxine Supplementation Improves the Activity of Recombinant Glutamate Decarboxylase and the Enzymatic Production of Gama-Aminobutyric Acid.

    PubMed

    Huang, Yan; Su, Lingqia; Wu, Jing

    2016-01-01

    Glutamate decarboxylase (GAD) catalyzes the irreversible decarboxylation of L-glutamate to the valuable food supplement γ-aminobutyric acid (GABA). In this study, GAD from Escherichia coli K12, a pyridoxal phosphate (PLP)-dependent enzyme, was overexpressed in E. coli. The GAD produced in media supplemented with 0.05 mM soluble vitamin B6 analog pyridoxine hydrochloride (GAD-V) activity was 154.8 U mL-1, 1.8-fold higher than that of GAD obtained without supplementation (GAD-C). Purified GAD-V exhibited increased activity (193.4 U mg-1, 1.5-fold higher than that of GAD-C), superior thermostability (2.8-fold greater than that of GAD-C), and higher kcat/Km (1.6-fold higher than that of GAD-C). Under optimal conditions in reactions mixtures lacking added PLP, crude GAD-V converted 500 g L-1 monosodium glutamate (MSG) to GABA with a yield of 100%, and 750 g L-1 MSG with a yield of 88.7%. These results establish the utility of pyridoxine supplementation and lay the foundation for large-scale enzymatic production of GABA. PMID:27438707

  8. Pyridoxine Supplementation Improves the Activity of Recombinant Glutamate Decarboxylase and the Enzymatic Production of Gama-Aminobutyric Acid

    PubMed Central

    Huang, Yan; Su, Lingqia; Wu, Jing

    2016-01-01

    Glutamate decarboxylase (GAD) catalyzes the irreversible decarboxylation of L-glutamate to the valuable food supplement γ-aminobutyric acid (GABA). In this study, GAD from Escherichia coli K12, a pyridoxal phosphate (PLP)-dependent enzyme, was overexpressed in E. coli. The GAD produced in media supplemented with 0.05 mM soluble vitamin B6 analog pyridoxine hydrochloride (GAD-V) activity was 154.8 U mL-1, 1.8-fold higher than that of GAD obtained without supplementation (GAD-C). Purified GAD-V exhibited increased activity (193.4 U mg-1, 1.5-fold higher than that of GAD-C), superior thermostability (2.8-fold greater than that of GAD-C), and higher kcat/Km (1.6-fold higher than that of GAD-C). Under optimal conditions in reactions mixtures lacking added PLP, crude GAD-V converted 500 g L-1 monosodium glutamate (MSG) to GABA with a yield of 100%, and 750 g L-1 MSG with a yield of 88.7%. These results establish the utility of pyridoxine supplementation and lay the foundation for large-scale enzymatic production of GABA. PMID:27438707

  9. Genetic basis of stage-specific melanism: a putative role for a cysteine sulfinic acid decarboxylase in insect pigmentation

    PubMed Central

    Saenko, S V; Jerónimo, M A; Beldade, P

    2012-01-01

    Melanism, the overall darkening of the body, is a widespread form of animal adaptation to particular environments, and includes bookcase examples of evolution by natural selection, such as industrial melanism in the peppered moth. The major components of the melanin biosynthesis pathway have been characterized in model insects, but little is known about the genetic basis of life-stage specific melanism such as cases described in some lepidopteran species. Here, we investigate two melanic mutations of Bicyclus anynana butterflies, called Chocolate and melanine, that exclusively affect pigmentation of the larval and adult stages, respectively. Our analysis of Mendelian segregation patterns reveals that the larval and adult melanic phenotypes are due to alleles at different, independently segregating loci. Our linkage mapping analysis excludes the pigmentation candidate gene black as the melanine locus, and implicates a gene encoding a putative pyridoxal phosphate-dependant cysteine sulfinic acid decarboxylase as the Chocolate locus. We show variation in coding sequence and in expression levels for this candidate larval melanism locus. This is the first study that suggests a biological function for this gene in insects. Our findings open up exciting opportunities to study the role of this locus in the evolution of adaptive variation in pigmentation, and the uncoupling of regulation of pigment biosynthesis across developmental stages with different ecologies and pressures on body coloration. PMID:22234245

  10. Islet glutamic acid decarboxylase modified by reactive oxygen species is recognized by antibodies from patients with type 1 diabetes mellitus

    PubMed Central

    Trigwell, S M; Radford, P M; Page, S R; Loweth, A C; James, R F L; Morgan, N G; Todd, I

    2001-01-01

    The generation of an autoimmune response against islet beta-cells is central to the pathogenesis of type 1 diabetes mellitus, and this response is driven by the stimulation of autoreactive lymphocytes by components of the beta-cells themselves. Reactive oxygen species (ROS) have been implicated in the beta-cell destruction which leads to type 1 diabetes and may modify beta-cell components so as to enhance their immunogenicity. We investigated the effects of oxidation reactions catalysed by copper or iron on the major beta-cell autoantigen glutamic acid decarboxylase (GAD). Lysates of purified rat islets were exposed to copper or iron sulphate with or without hydrogen peroxide or ascorbic acid. Immunostaining showed that these treatments generated high molecular weight covalently linked aggregates containing GAD. These are not formed by intermolecular disulphide bonds between cysteine residues since they cannot be resolved into monomeric form when electrophoresed under extreme reducing conditions. There was no modification of insulin or pro-insulin by ROS. The same oxidative changes to GAD could be induced in viable islet cells treated with copper sulphate and hydrogen peroxide, and thus the modifications are not an artefact of the catalysed oxidation of cell-free lysates. Sera from patients with type 1 diabetes and stiffman syndrome containing GAD antibodies reacted predominantly with the highest molecular weight modified protein band of GAD: normal human sera did not precipitate GAD. Thus, oxidatively modified aggregates of GAD react with serum antibodies of type 1 diabetes patients and some SMS patients: this is consistent with oxidative modifications of autoantigens being relevant to the pathogenesis of type 1 diabetes. PMID:11703367

  11. Islet glutamic acid decarboxylase modified by reactive oxygen species is recognized by antibodies from patients with type 1 diabetes mellitus.

    PubMed

    Trigwell, S M; Radford, P M; Page, S R; Loweth, A C; James, R F; Morgan, N G; Todd, I

    2001-11-01

    The generation of an autoimmune response against islet beta-cells is central to the pathogenesis of type 1 diabetes mellitus, and this response is driven by the stimulation of autoreactive lymphocytes by components of the beta-cells themselves. Reactive oxygen species (ROS) have been implicated in the beta-cell destruction which leads to type 1 diabetes and may modify beta-cell components so as to enhance their immunogenicity. We investigated the effects of oxidation reactions catalysed by copper or iron on the major beta-cell autoantigen glutamic acid decarboxylase (GAD). Lysates of purified rat islets were exposed to copper or iron sulphate with or without hydrogen peroxide or ascorbic acid. Immunostaining showed that these treatments generated high molecular weight covalently linked aggregates containing GAD. These are not formed by intermolecular disulphide bonds between cysteine residues since they cannot be resolved into monomeric form when electrophoresed under extreme reducing conditions. There was no modification of insulin or pro-insulin by ROS. The same oxidative changes to GAD could be induced in viable islet cells treated with copper sulphate and hydrogen peroxide, and thus the modifications are not an artefact of the catalysed oxidation of cell-free lysates. Sera from patients with type 1 diabetes and stiffman syndrome containing GAD antibodies reacted predominantly with the highest molecular weight modified protein band of GAD: normal human sera did not precipitate GAD. Thus, oxidatively modified aggregates of GAD react with serum antibodies of type 1 diabetes patients and some SMS patients: this is consistent with oxidative modifications of autoantigens being relevant to the pathogenesis of type 1 diabetes. PMID:11703367

  12. Enhancement of the catalytic activity of ferulic acid decarboxylase from Enterobacter sp. Px6-4 through random and site-directed mutagenesis.

    PubMed

    Lee, Hyunji; Park, Jiyoung; Jung, Chaewon; Han, Dongfei; Seo, Jiyoung; Ahn, Joong-Hoon; Chong, Youhoon; Hur, Hor-Gil

    2015-11-01

    The enzyme ferulic acid decarboxylase (FADase) from Enterobacter sp. Px6-4 catalyzes the decarboxylation reaction of lignin monomers and phenolic compounds such as p-coumaric acid, caffeic acid, and ferulic acid into their corresponding 4-vinyl derivatives, that is, 4-vinylphenol, 4-vinylcatechol, and 4-vinylguaiacol, respectively. Among various ferulic acid decarboxylase enzymes, we chose the FADase from Enterobacter sp. Px6-4, whose crystal structure is known, and produced mutants to enhance its catalytic activity by random and site-directed mutagenesis. After three rounds of sequential mutations, FADase(F95L/D112N/V151I) showed approximately 34-fold higher catalytic activity than wild-type for the production of 4-vinylguaiacol from ferulic acid. Docking analyses suggested that the increased activity of FADase(F95L/D112N/V151I) could be due to formation of compact active site compared with that of the wild-type FADase. Considering the amount of phenolic compounds such as lignin monomers in the biomass components, successfully bioengineered FADase(F95L/D112N/V151I) from Enterobacter sp. Px6-4 could provide an ecofriendly biocatalytic tool for producing diverse styrene derivatives from biomass. PMID:26059194

  13. Improvement of the Rett Syndrome Phenotype in a Mecp2 Mouse Model Upon Treatment with Levodopa and a Dopa-Decarboxylase Inhibitor

    PubMed Central

    Szczesna, Karolina; de la Caridad, Olga; Petazzi, Paolo; Soler, Marta; Roa, Laura; Saez, Mauricio A; Fourcade, Stéphane; Pujol, Aurora; Artuch-Iriberri, Rafael; Molero-Luis, Marta; Vidal, August; Huertas, Dori; Esteller, Manel

    2014-01-01

    Rett Syndrome is a neurodevelopmental autism spectrum disorder caused by mutations in the gene coding for methyl CpG-binding protein (MeCP2). The disease is characterized by abnormal motor, respiratory, cognitive impairment, and autistic-like behaviors. No effective treatment of the disorder is available. Mecp2 knockout mice have a range of physiological and neurological abnormalities that resemble the human syndrome and can be used as a model to interrogate new therapies. Herein, we show that the combined administration of Levodopa and a Dopa-decarboxylase inhibitor in RTT mouse models is well tolerated, diminishes RTT-associated symptoms, and increases life span. The amelioration of RTT symptomatology is particularly significant in those features controlled by the dopaminergic pathway in the nigrostratium, such as mobility, tremor, and breathing. Most important, the improvement of the RTT phenotype upon use of the combined treatment is reflected at the cellular level by the development of neuronal dendritic growth. However, much work is required to extend the duration of the benefit of the described preclinical treatment. PMID:24917201

  14. Improvement of the Rett syndrome phenotype in a MeCP2 mouse model upon treatment with levodopa and a dopa-decarboxylase inhibitor.

    PubMed

    Szczesna, Karolina; de la Caridad, Olga; Petazzi, Paolo; Soler, Marta; Roa, Laura; Saez, Mauricio A; Fourcade, Stéphane; Pujol, Aurora; Artuch-Iriberri, Rafael; Molero-Luis, Marta; Vidal, August; Huertas, Dori; Esteller, Manel

    2014-11-01

    Rett Syndrome is a neurodevelopmental autism spectrum disorder caused by mutations in the gene coding for methyl CpG-binding protein (MeCP2). The disease is characterized by abnormal motor, respiratory, cognitive impairment, and autistic-like behaviors. No effective treatment of the disorder is available. Mecp2 knockout mice have a range of physiological and neurological abnormalities that resemble the human syndrome and can be used as a model to interrogate new therapies. Herein, we show that the combined administration of Levodopa and a Dopa-decarboxylase inhibitor in RTT mouse models is well tolerated, diminishes RTT-associated symptoms, and increases life span. The amelioration of RTT symptomatology is particularly significant in those features controlled by the dopaminergic pathway in the nigrostratium, such as mobility, tremor, and breathing. Most important, the improvement of the RTT phenotype upon use of the combined treatment is reflected at the cellular level by the development of neuronal dendritic growth. However, much work is required to extend the duration of the benefit of the described preclinical treatment. PMID:24917201

  15. Lower Expression of Glutamic Acid Decarboxylase 67 in the Prefrontal Cortex in Schizophrenia: Contribution of Altered Regulation by Zif268

    PubMed Central

    Kimoto, Sohei; Bazmi, H. Holly; Lewis, David A.

    2015-01-01

    Objective Cognitive deficits of schizophrenia may be due at least in part to lower expression of the 67-kDa isoform of glutamic acid decarboxylase (GAD67), a key enzyme for GABA synthesis, in the dorsolateral prefrontal cortex of individuals with schizophrenia. However, little is known about the molecular regulation of lower cortical GAD67 levels in schizophrenia. The GAD67 promoter region contains a conserved Zif268 binding site, and Zif268 activation is accompanied by increased GAD67 expression. Thus, altered expression of the immediate early gene Zif268 may contribute to lower levels of GAD67 mRNA in the dorsolateral prefrontal cortex in schizophrenia. Method The authors used polymerase chain reaction to quantify GAD67 and Zif268 mRNA levels in dorsolateral pre-frontal cortex area 9 from 62 matched pairs of schizophrenia and healthy comparison subjects, and in situ hybridization to assess Zif268 expression at laminar and cellular levels of resolution. The effects of potentially confounding variables were assessed in human subjects, and the effects of antipsychotic treatments were tested in antipsychotic-exposed monkeys. The specificity of the Zif268 findings was assessed by quantifying mRNA levels for other immediate early genes. Results GAD67 and Zif268 mRNA levels were significantly lower and were positively correlated in the schizophrenia subjects. Both Zif268 mRNA-positive neuron density and Zif268 mRNA levels per neuron were significantly lower in the schizophrenia subjects. These findings were robust to the effects of the confounding variables examined and differed from other immediate early genes. Conclusions Deficient Zif268 mRNA expression may contribute to lower cortical GAD67 levels in schizophrenia, suggesting a potential mechanistic basis for altered cortical GABA synthesis and impaired cognition in schizophrenia. PMID:24874453

  16. A novel expression platform for the production of diabetes-associated autoantigen human glutamic acid decarboxylase (hGAD65)

    PubMed Central

    Wang, Xiaofeng; Brandsma, Martin; Tremblay, Reynald; Maxwell, Denis; Jevnikar, Anthony M; Huner, Norm; Ma, Shengwu

    2008-01-01

    Background Human glutamic acid decarboxylase 65 (hGAD65) is a key autoantigen in type 1 diabetes, having much potential as an important marker for the prediction and diagnosis of type 1 diabetes, and for the development of novel antigen-specific therapies for the treatment of type 1 diabetes. However, recombinant production of hGAD65 using conventional bacterial or mammalian cell culture-based expression systems or nuclear transformed plants is limited by low yield and low efficiency. Chloroplast transformation of the unicellular eukaryotic alga Chlamydomonas reinhardtii may offer a potential solution. Results A DNA cassette encoding full-length hGAD65, under the control of the C. reinhardtii chloroplast rbcL promoter and 5'- and 3'-UTRs, was constructed and introduced into the chloroplast genome of C. reinhardtii by particle bombardment. Integration of hGAD65 DNA into the algal chloroplast genome was confirmed by PCR. Transcriptional expression of hGAD65 was demonstrated by RT-PCR. Immunoblotting verified the expression and accumulation of the recombinant protein. The antigenicity of algal-derived hGAD65 was demonstrated with its immunoreactivity to diabetic sera by ELISA and by its ability to induce proliferation of spleen cells from NOD mice. Recombinant hGAD65 accumulated in transgenic algae, accounts for approximately 0.25–0.3% of its total soluble protein. Conclusion Our results demonstrate the potential value of C. reinhardtii chloroplasts as a novel platform for rapid mass production of immunologically active hGAD65. This demonstration opens the future possibility for using algal chloroplasts as novel bioreactors for the production of many other biologically active mammalian therapeutic proteins. PMID:19014643

  17. Assessment of the effects of glutamic acid decarboxylase antibodies and trace elements on cognitive performance in older adults

    PubMed Central

    Alghadir, Ahmad H; Gabr, Sami A; Al-Eisa, Einas S

    2015-01-01

    Background Homeostatic imbalance of trace elements such as iron (Fe), copper (Cu), and zinc (Zn) demonstrated adverse effects on brain function among older adults. Objective The present study aimed to investigate the effects of trace elements and the presence of anti-glutamic acid decarboxylase antibodies (GADAs) in human cognitive abilities among healthy older adults. Methods A total of 100 healthy subjects (65 males, 35 females; age range; 64–96 years) were recruited for this study. Based on Loewenstein Occupational Therapy Cognitive Assessment (LOTCA) score, the participants were classified according to cognitive performance into normal (n=45), moderate (n=30), and severe (n=25). Cognitive functioning, leisure-time physical activity (LTPA), serum trace elements – Fe, Cu, Zn, Zn/Cu, and GADAs were assessed using LOTCA battery, pre-validated physical activity (PA) questionnaire, atomic absorption, and immunoassay techniques, respectively. Results Approximately 45% of the study population (n=45) had normal distribution of cognitive function and 55% of the study population (n=55) had abnormal cognitive function; they were classified into moderate (score 62–92) and severe (score 31–62). There was a significant reduction in the level of Zn and Zn/Cu ratio along with an increase in the level of Fe, Cu, and anti-GADAs in subjects of severe (P=0.01) and moderate (P=0.01) cognitive performance. LOTCA-cognitive scores correlated positively with sex, HbA1c, Fe, Cu, Zn, and Zn/Cu ratio, and negatively with age, PA, body mass index, and anti-GADAs. Significant inter-correlation was reported between serum trace element concentrations and anti-GADAs which suggest producing a cognitive decline via oxidative and neural damage mechanism. Conclusion This study found significant associations among trace elements, anti-GADAs, and cognitive function in older adults. The homeostatic balance of trace elements should be recommended among older adults for better cognitive

  18. Crystal Structures of Apo and Liganded 4-Oxalocrotonate Decarboxylase Uncover a Structural Basis for the Metal-Assisted Decarboxylation of a Vinylogous β-Keto Acid.

    PubMed

    Guimarães, Samuel L; Coitinho, Juliana B; Costa, Débora M A; Araújo, Simara S; Whitman, Christian P; Nagem, Ronaldo A P

    2016-05-10

    The enzymes in the catechol meta-fission pathway have been studied for more than 50 years in several species of bacteria capable of degrading a number of aromatic compounds. In a related pathway, naphthalene, a toxic polycyclic aromatic hydrocarbon, is fully degraded to intermediates of the tricarboxylic acid cycle by the soil bacteria Pseudomonas putida G7. In this organism, the 83 kb NAH7 plasmid carries several genes involved in this biotransformation process. One enzyme in this route, NahK, a 4-oxalocrotonate decarboxylase (4-OD), converts 2-oxo-3-hexenedioate to 2-hydroxy-2,4-pentadienoate using Mg(2+) as a cofactor. Efforts to study how 4-OD catalyzes this decarboxylation have been hampered because 4-OD is present in a complex with vinylpyruvate hydratase (VPH), which is the next enzyme in the same pathway. For the first time, a monomeric, stable, and active 4-OD has been expressed and purified in the absence of VPH. Crystal structures for NahK in the apo form and bonded with five substrate analogues were obtained using two distinct crystallization conditions. Analysis of the crystal structures implicates a lid domain in substrate binding and suggests roles for specific residues in a proposed reaction mechanism. In addition, we assign a possible function for the NahK N-terminal domain, which differs from most of the other members of the fumarylacetoacetate hydrolase superfamily. Although the structural basis for metal-dependent β-keto acid decarboxylases has been reported, this is the first structural report for that of a vinylogous β-keto acid decarboxylase and the first crystal structure of a 4-OD. PMID:27082660

  19. Improving the acidic stability of Staphylococcus aureus α-acetolactate decarboxylase in Bacillus subtilis by changing basic residues to acidic residues.

    PubMed

    Zhang, Xian; Rao, Zhiming; Li, Jingjing; Zhou, Junping; Yang, Taowei; Xu, Meijuan; Bao, Teng; Zhao, Xiaojing

    2015-04-01

    The α-acetolactate decarboxylase (ALDC) can reduce diacetyl fleetly to promote mature beer. A safe strain Bacillus subtilis WB600 for high-yield production of ALDC was constructed with the ALDC gene saald from Staphylococcus aureus L3-15. SDS-PAGE analysis revealed that S. aureus α-acetolactate decarboxylase (SaALDC) was successfully expressed in recombinant B. siutilis strain. The enzyme SaALDC was purified using Ni-affinity chromatography and showed a maximum activity at 45 °C and pH 6.0. The values of K m and V max were 17.7 μM and 2.06 mM min(-1), respectively. Due to the unstable property of SaALDC at low pH conditions that needed in brewing process, site-directed mutagenesis was proposed for improving the acidic stability of SaALDC. Homology comparative modeling analysis showed that the mutation (K52D) gave rise to the negative-electrostatic potential on the surface of protein while the numbers of hydrogen bonds between the mutation site (N43D) and the around residues increased. Taken together the effect of mutation N43D-K52D, recombinant SaALDCN43D-K52D showed dramatically improved acidic stability with prolonged half-life of 3.5 h (compared to the WT of 1.5 h) at pH 4.0. In a 5-L fermenter, the recombinant B. subtilis strain that could over-express SaALDCN43D-K52D exhibited a high yield of 135.8 U mL(-1) of SaALDC activity, about 320 times higher comparing to 0.42 U mL(-1) of S. aureus L3-15. This work proposed a  strategy for improving the acidic stability of SaALDC in the  B. subtilis host. PMID:25543264

  20. HosA, a MarR Family Transcriptional Regulator, Represses Nonoxidative Hydroxyarylic Acid Decarboxylase Operon and Is Modulated by 4-Hydroxybenzoic Acid.

    PubMed

    Roy, Ajit; Ranjan, Akash

    2016-02-23

    Members of the Multiple antibiotic resistance Regulator (MarR) family of DNA binding proteins regulate transcription of a wide array of genes required for virulence and pathogenicity of bacteria. The present study reports the molecular characterization of HosA (Homologue of SlyA), a MarR protein, with respect to its target gene, DNA recognition motif, and nature of its ligand. Through a comparative genomics approach, we demonstrate that hosA is in synteny with nonoxidative hydroxyarylic acid decarboxylase (HAD) operon and is present exclusively within the mutS-rpoS polymorphic region in nine different genera of Enterobacteriaceae family. Using molecular biology and biochemical approach, we demonstrate that HosA binds to a palindromic sequence downstream to the transcription start site of divergently transcribed nonoxidative HAD operon and represses its expression. Furthermore, in silico analysis showed that the recognition motif for HosA is highly conserved in the upstream region of divergently transcribed operon in different genera of Enterobacteriaceae family. A systematic chemical search for the physiological ligand revealed that 4-hydroxybenzoic acid (4-HBA) interacts with HosA and derepresses HosA mediated repression of the nonoxidative HAD operon. Based on our study, we propose a model for molecular mechanism underlying the regulation of nonoxidative HAD operon by HosA in Enterobacteriaceae family. PMID:26818787

  1. Structural and Mechanistic Studies on Klebsiella pneumoniae 2-Oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline Decarboxylase

    SciTech Connect

    French, Jarrod B.; Ealick, Steven E.

    2010-11-12

    The stereospecific oxidative degradation of uric acid to (S)-allantoin was recently shown to proceed via three enzymatic steps. The final conversion is a decarboxylation of the unstable intermediate 2-oxo-4-hydroxy-4-carboxy-5-ureidoimidazoline (OHCU) and is catalyzed by OHCU decarboxylase. Here we present the structures of Klebsiella pneumoniae OHCU decarboxylase in unliganded form and with bound allantoin. These structures provide evidence that ligand binding organizes the active site residues for catalysis. Modeling of the substrate and intermediates provides additional support for this hypothesis. In addition we characterize the steady state kinetics of this enzyme and report the first OHCU decarboxylase inhibitor, allopurinol, a structural isomer of hypoxanthine. This molecule is a competitive inhibitor of K. pneumoniae OHCU decarboxylase with a K{sub i} of 30 {+-} 2 {micro}m. Circular dichroism measurements confirm structural observations that this inhibitor disrupts the necessary organization of the active site. Our structural and biochemical studies also provide further insights into the mechanism of catalysis of OHCU decarboxylation.

  2. Raman micro-spectroscopic investigation of the interaction of cultured HCT116 colon cancer cells with alpha-difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase

    NASA Astrophysics Data System (ADS)

    Akyuz, S.; Ozel, A. E.; Balci, K.; Akyuz, T.; Coker, A.; Arisan, E. D.; Palavan-Unsal, N.; Ozalpan, A.

    2011-05-01

    The interaction of cultured colon cancer cells with alpha-difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase, has been investigated, using Raman micro-spectroscopy, in order to investigate DFMO induced effects. Raman spectra of the cultured HCT116 colon cancer cells treated with DFMO at different concentrations (0, 1, 2.5, 5, and 7.5 mM) were recorded in the range 550-2300 cm -1. It has been shown that second derivative profile of the raw Raman spectrum of the colon cancer cells (i.e., the original experimental spectrum without any computational corrections) discriminates the weak but sharp bands from the strong, broad fluorescence background, and gives information about the position of the peaks and their band widths. The relative integrated intensities of the 781 cm -1 and 788 cm -1 DNA/RNA marker bands to that of 1451 cm -1 band are found to decrease by addition of DFMO. Up to 65% reduction in the magnitude of the 1003 cm -1 band, the characteristic phenylalanine ring breathing mode, in comparison to that of 1451 band, is observed. The results indicate DFMO induced apoptosis. On the other hand the intensity ratio of the tyrosine Fermi doubled around 830 cm -1 and 850 cm -1, which is a marker of hydrogen-bonding state of phenolic OH, is changed. The addition of DFMO may alter the tyrosine environment in cells, and parts of tyrosine residues are exposed. We also observed some modifications in amide I band, pointing out the alterations of the secondary structure of cell proteins by the presence of DFMO.

  3. Immunocytochemical localization of glutamic acid decarboxylase (GAD) and glutamine synthetase (GS) in the area postrema of the cat. Light and electron microscopy

    NASA Technical Reports Server (NTRS)

    D'Amelio, Fernando E.; Mehler, William R.; Gibbs, Michael A.; Eng, Lawrence F.; Wu, Jang-Yen

    1987-01-01

    Morphological evidence is presented of the existence of the putative neurotransmitter gamma-aminobutyric acid (GABA) in axon terminals and of glutamine synthetase (GS) in ependymoglial cells and astroglial components of the area postrema (AP) of the cat. Purified antiserum directed against the GABA biosynthetic enzyme glutamic acid decarboxylase (GAD) and GS antiserum were used. The results showed that punctate structures of variable size corresponding to axon terminals exhibited GAD-immunoreactivity and were distributed in varying densities. The greatest accumulation occurred in the caudal and middle segment of the AP and particularly in the area subpostrema, where the aggregation of terminals was extremely dense. The presence of both GAD-immunoreactive profiles and GS-immunostained ependymoglial cells and astrocytes in the AP provide further evidence of the functional correlation between the two enzymes.

  4. Dual mechanisms regulating glutamate decarboxylases and accumulation of gamma-aminobutyric acid in tea (Camellia sinensis) leaves exposed to multiple stresses

    PubMed Central

    Mei, Xin; Chen, Yiyong; Zhang, Lingyun; Fu, Xiumin; Wei, Qing; Grierson, Don; Zhou, Ying; Huang, Yahui; Dong, Fang; Yang, Ziyin

    2016-01-01

    γ-Aminobutyric acid (GABA) is one of the major inhibitory neurotransmitters in the central nervous system. It has multiple positive effects on mammalian physiology and is an important bioactive component of tea (Camellia sinensis). GABA generally occurs at a very low level in plants but GABA content increases substantially after exposure to a range of stresses, especially oxygen-deficiency. During processing of tea leaves, a combination of anoxic stress and mechanical damage are essential for the high accumulation of GABA. This is believed to be initiated by a change in glutamate decarboxylase activity, but the underlying mechanisms are unclear. In the present study we characterized factors regulating the expression and activity of three tea glutamate decarboxylase genes (CsGAD1, 2, and 3), and their encoded enzymes. The results suggests that, unlike the model plant Arabidopsis thaliana, there are dual mechanisms regulating the accumulation of GABA in tea leaves exposed to multiple stresses, including activation of CsGAD1 enzymatic activity by calmodulin upon the onset of the stress and accumulation of high levels of CsGAD2 mRNA induced by a combination of anoxic stress and mechanical damage. PMID:27021285

  5. Dual mechanisms regulating glutamate decarboxylases and accumulation of gamma-aminobutyric acid in tea (Camellia sinensis) leaves exposed to multiple stresses.

    PubMed

    Mei, Xin; Chen, Yiyong; Zhang, Lingyun; Fu, Xiumin; Wei, Qing; Grierson, Don; Zhou, Ying; Huang, Yahui; Dong, Fang; Yang, Ziyin

    2016-01-01

    γ-Aminobutyric acid (GABA) is one of the major inhibitory neurotransmitters in the central nervous system. It has multiple positive effects on mammalian physiology and is an important bioactive component of tea (Camellia sinensis). GABA generally occurs at a very low level in plants but GABA content increases substantially after exposure to a range of stresses, especially oxygen-deficiency. During processing of tea leaves, a combination of anoxic stress and mechanical damage are essential for the high accumulation of GABA. This is believed to be initiated by a change in glutamate decarboxylase activity, but the underlying mechanisms are unclear. In the present study we characterized factors regulating the expression and activity of three tea glutamate decarboxylase genes (CsGAD1, 2, and 3), and their encoded enzymes. The results suggests that, unlike the model plant Arabidopsis thaliana, there are dual mechanisms regulating the accumulation of GABA in tea leaves exposed to multiple stresses, including activation of CsGAD1 enzymatic activity by calmodulin upon the onset of the stress and accumulation of high levels of CsGAD2 mRNA induced by a combination of anoxic stress and mechanical damage. PMID:27021285

  6. Efficient production of gamma-aminobutyric acid using Escherichia coli by co-localization of glutamate synthase, glutamate decarboxylase, and GABA transporter.

    PubMed

    Dung Pham, Van; Somasundaram, Sivachandiran; Lee, Seung Hwan; Park, Si Jae; Hong, Soon Ho

    2016-01-01

    Gamma-aminobutyric acid (GABA) is an important bio-product, which is used in pharmaceutical formulations, nutritional supplements, and biopolymer monomer. The traditional GABA process involves the decarboxylation of glutamate. However, the direct production of GABA from glucose is a more efficient process. To construct the recombinant strains of Escherichia coli, a novel synthetic scaffold was introduced. By carrying out the co-localization of glutamate synthase, glutamate decarboxylase, and GABA transporter, we redirected the TCA cycle flux to GABA pathway. The genetically engineered E. coli strain produced 1.08 g/L of GABA from 10 g/L of initial glucose. Thus, with the introduction of a synthetic scaffold, we increased GABA production by 2.2-fold. The final GABA concentration was increased by 21.8% by inactivating competing pathways. PMID:26620318

  7. Rapid Normalization of High Glutamic Acid Decarboxylase Autoantibody Titers and Preserved Endogenous Insulin Secretion in a Patient with Diabetes Mellitus: A Case Report and Literature Review.

    PubMed

    Ohara, Nobumasa; Kaneko, Masanori; Furukawa, Tatsuo; Koike, Tadashi; Sone, Hirohito; Tanaka, Shoichiro; Kaneko, Kenzo; Kamoi, Kyuzi

    2016-01-01

    A 59-year-old Japanese woman developed diabetes mellitus without ketoacidosis in the presence of glutamic acid decarboxylase autoantibody (GADA) (24.7 U/mL). After the amelioration of her hyperglycemia, the patient had a relatively preserved serum C-peptide level. Her endogenous insulin secretion capacity remained almost unchanged during 5 years of insulin therapy. The patient's GADA titers normalized within 15 months. The islet-related autoantibodies, including GADA, are believed to be produced following the autoimmune destruction of pancreatic beta cells and are predictive markers of type 1 diabetes mellitus. Therefore, the transient appearance of GADA in our patient may have reflected pancreatic autoimmune processes that terminated without progression to insulin deficiency. PMID:26935368

  8. Tomato aromatic amino acid decarboxylases participate in synthesis of the flavor volatiles 2-phenylethanol and 2-phenylacetaldehyde

    PubMed Central

    Tieman, Denise; Taylor, Mark; Schauer, Nicolas; Fernie, Alisdair R.; Hanson, Andrew D.; Klee, Harry J.

    2006-01-01

    An important phenylalanine-derived volatile compound produced by plants is 2-phenylethanol. It is a major contributor to flavor in many foods, including fresh fruits, such as tomato, and an insect-attracting scent in roses and many other flowers. Despite the centrality of 2-phenylethanol to flavor and fragrance, the plant genes responsible for its synthesis have not been identified. Here, we describe a biosynthetic pathway for 2-phenylethanol and other phenylalanine-derived volatiles in tomato fruits and a small family of decarboxylases (LeAADC1A, LeAADC1B, and LeAADC2) that can mediate that pathway's first step. These enzymes each catalyze conversion of phenylalanine to phenethylamine and tyrosine to tyramine. Although tyrosine is the preferred substrate in vitro, phenylalanine levels in tomato fruits far exceed those of tyrosine, indicating that phenylalanine is a physiological substrate. Consistent with this view, overexpression of either LeAADC1A or LeAADC2 in transgenic tomato plants resulted in fruits with up to 10-fold increased emissions of the products of the pathway, including 2-phenylacetaldehyde, 2-phenylethanol, and 1-nitro-2-phenylethane. Further, antisense reduction of LeAADC2 significantly reduced emissions of these volatiles. Besides establishing a biosynthetic route, these results show that it is possible to change phenylalanine-based flavor and aroma volatiles in plants by manipulating expression of a single gene. PMID:16698923

  9. Cellular characterization of a new irreversible inhibitor of S-adenosylmethionine decarboxylase and its use in determining the relative abilities of individual polyamines to sustain growth and viability of L1210 cells.

    PubMed Central

    Kramer, D L; Khomutov, R M; Bukin, Y V; Khomutov, A R; Porter, C W

    1989-01-01

    S-(5'-Deoxy-5'-adenosyl)methylthioethylhydroxylamine (AMA) is an irreversible inhibitor of S-adenosylmethionine (AdoMet) decarboxylase, which is designed to bind covalently the pyruvate residue at the enzyme active site. In the present study the cellular effects of AMA were characterized for the first time in cultured L1210 leukaemia cells. At the approximate IC50 (concn. giving 50% inhibition; 100 microM), AMA decreased spermidine and spermine by more than 80% at 48 h while increasing putrescine more than 10-fold. As an indication of enzyme specificity, growth inhibition was fully prevented with exogenous spermidine. When compared with the irreversible inhibitor of ornithine decarboxylase, alpha-difluoromethylornithine (DFMO), at similar growth-inhibitory concentrations, AMA was less cytotoxic, as determined by colony-formation efficiency. In combination with AMA, DFMO eliminated the rise in putrescine and decreased growth in an additive manner. The near-total depletion of intracellular polyamine pools achieved with the drug combination provided an opportunity to examine the relative abilities of individual polyamines to support growth and viability. Of the three exogenously supplied polyamines, only spermidine fully sustained cell growth and viability at control values during incubations totalling 120 h. By contrast, spermine supported growth at 23% of control and viability at 8%. Putrescine was similarly ineffective, supporting growth at 13% of control and viability at 7%. The data indicate that, in L1210 cells, spermidine is apparently the preferred polyamine in growth-related functions and is capable of fully supporting cell growth by itself. However, because spermine and putrescine can also support growth to some extent, maximum interference with growth and viability is best achieved by strategies which deplete all three polyamine pools. PMID:2497733

  10. Glutamic acid decarboxylase activity is stimulated in quail retina neuronal cells transformed by Rous sarcoma virus and is regulated by pp60v-src.

    PubMed Central

    Crisanti, P; Lorinet, A M; Calothy, G; Pessac, B

    1985-01-01

    Rous sarcoma virus (RSV) stimulates in quail embryo neuro-retina (NR) cultures the specific activity of glutamic acid decarboxylase (GAD), the enzyme responsible for the synthesis of gamma-aminobutyric acid, a major inhibitory neurotransmitter in NR and in central nervous system. In quail embryo NR cultures transformed by ts NY-68, a thermodependent transformation-defective mutant of RSV, stimulation of GAD activity is regulated by pp60v-src, the product of the src gene of RSV. Fibroblasts and myoblasts have a very low GAD activity that is not stimulated after transformation by RSV. Neuronal clones, previously derived from ts NY-68-transformed established NR cell lines, have a high GAD activity which is regulated by pp60v-src, while other clones have a low GAD activity apparently not regulated by pp60v-src. These data indicate that pp60v-src selectively activates the expression of GAD in distinct neuronal cells of quail embryo NR cultures transformed by RSV. GAD activity is also stimulated in NR cells infected with viruses containing v-mil. PMID:2992933

  11. Mechanism of the Novel Prenylated Flavin-Containing Enzyme Ferulic Acid Decarboxylase Probed by Isotope Effects and Linear Free-Energy Relationships.

    PubMed

    Ferguson, Kyle L; Arunrattanamook, Nattapol; Marsh, E Neil G

    2016-05-24

    Ferulic acid decarboxylase from Saccharomyces cerevisiae catalyzes the decarboxylation of phenylacrylic acid to form styrene using a newly described prenylated flavin mononucleotide cofactor. A mechanism has been proposed, involving an unprecedented 1,3-dipolar cyclo-addition of the prenylated flavin with the α═β bond of the substrate that serves to activate the substrate toward decarboxylation. We measured a combination of secondary deuterium kinetic isotope effects (KIEs) at the α- and β-positions of phenylacrylic acid together with solvent deuterium KIEs. The solvent KIE is 3.3 on Vmax/KM but is close to unity on Vmax, indicating that proton transfer to the product occurs before the rate-determining step. The secondary KIEs are normal at both the α- and β-positions but vary in magnitude depending on whether the reaction is performed in H2O or D2O. In D2O, the enzyme catalyzed the exchange of deuterium into styrene; this reaction was dependent on the presence of bicarbonate. This observation implies that CO2 release must occur after protonation of the product. Further information was obtained from a linear free-energy analysis of the reaction through the use of a range of para- and meta-substituted phenylacrylic acids. Log(kcat/KM) for the reaction correlated well with the Hammett σ(-) parameter with ρ = -0.39 ± 0.03; r(2) = 0.93. The negative ρ value and secondary isotope effects are consistent with the rate-determining step being the formation of styrene from the prenylated flavin-product adduct through a cyclo-elimination reaction. PMID:27119435

  12. Deficiency of the 65 kDa isoform of glutamic acid decarboxylase impairs extinction of cued but not contextual fear memory.

    PubMed

    Sangha, Susan; Narayanan, Rajeevan T; Bergado-Acosta, Jorge R; Stork, Oliver; Seidenbecher, Thomas; Pape, Hans-Christian

    2009-12-16

    Extinction procedures are clinically relevant for reducing pathological fear, and the mechanisms of fear regulation are a subject of intense research. The amygdala, hippocampus, and prefrontal cortex (PFC) have all been suggested to be key brain areas in extinction of conditioned fear. GABA has particularly been implicated in extinction learning, and the 65 kDa isoform of glutamic acid decarboxylase (GAD65) may be important in elevating GABA levels in response to environmental signals. Extinction of conditioned fear was examined in Gad65(-/-) mice while recording local field potentials from the amygdala, hippocampus, and PFC simultaneously while monitoring behavior. Gad65(-/-) mice showed generalization of cued fear, as reported previously, and impaired extinction of cued fear, such that fear remained high across extinction training. This endurance in cued fear was associated with theta frequency synchronization between the amygdala and hippocampus. Extinction of contextual fear, however, was unaltered in Gad65(-/-) mice when compared with wild-type littermates. The data imply that GAD65 plays a critical role in regulating cued fear responses during extinction learning and that, during this process, GABAergic signaling is involved in modulating synchronized activity between the amygdala and hippocampus. In view of the more pronounced effect on cued versus contextual fear extinction, these influences may rely more on GABAergic mechanisms in the amygdala. PMID:20016086

  13. Therapeutic alteration of insulin-dependent diabetes mellitus progression by T cell tolerance to glutamic acid decarboxylase 65 peptides in vitro and in vivo.

    PubMed

    Wilson, S S; White, T C; DeLuca, D

    2001-07-01

    We have reported previously that nonobese diabetic (NOD) fetal pancreas organ cultures lose the ability to produce insulin when maintained in contact with NOD fetal thymus organ cultures (FTOC). Initial studies indicated that exposure to glutamic acid decarboxylase (GAD65) peptides in utero resulted in delay or transient protection from insulin-dependent diabetes mellitus (IDDM) in NOD mice. We also found that exposure of young adult NOD mice to the same peptides could result in acceleration of the disease. To more closely examine the effects of early and late exposure to diabetogenic Ags on T cells, we applied peptides derived from GAD65 (GAD AA 246-266, 509-528, and 524-543), to our "in vitro IDDM" (ivIDDM) model. T cells derived from NOD FTOC primed during the latter stages of organ culture, when mature T cell phenotypes are present, had the ability to proliferate to GAD peptides. ivIDDM was exacerbated under these conditions, suggesting that GAD responsiveness correlates with the ivIDDM phenotype, and parallels the acceleration of IDDM we had seen in young adult NOD mice. When GAD peptides were present during the initiation of FTOC, GAD proliferative responses were inhibited, and ivIDDM was reduced. This result suggests that tolerance to GAD peptides may reduce the production of diabetogenic T cells or their capacity to respond, as suggested by the in utero therapies studied in NOD mice. PMID:11418696

  14. Molecular cloning of genomic DNA and chromosomal assignment of the gene for human aromatic L-amino acid decarboxylase, the enzyme for catecholamine and serotonin biosynthesis

    SciTech Connect

    Sumi-Ichinose, Chiho ); Ichinose, Hiroshi; Nagatsu, Toshiharu ); Takahashi, Eiichi; Hori, Tadaaki )

    1992-03-03

    Aromatic L-amino acid decarboxylase (AADC) catalyzes the decarboxylation of both L-3,4-dihydroxyphenylalanine and L-5-hydroxytryptophan to dopamine and serotonin, respectively, which are major mammalian neurotransmitters and hormones belonging to catecholamines and indoleamines. This report describes the organization of the human AADC gene. The authors proved that the gene of human AADC consists of 15 exons spanning more than 85 kilobases and exists as a single copy in the haploid genome. The boundaries between exon and intron followed the AG/GT rule. The sizes of exons and introns ranged from 20 to 400 bp and from 1.0 to 17.7 kb, respectively, while the sizes of four introns were not determined. Untranslated regions located in the 5{prime} region of mRNA were encoded by two exons, exons 1 and 2. The transcriptional starting point was determined around G at position {minus}111 by primer extension and S1 mapping. There were no typical TATA box' and CAAT box' within 540 bp from the transcriptional starting point. The human AADC gene was mapped to chromosome band 7p12.1-p12.3 by fluorescence in situ hybridization. This is the first report on the genomic structure and chromosomal localization of the AADC gene in mammals.

  15. Immunocytochemical localization of glutamic acid decarboxylase (GAD) and substance P in neural areas mediating motion-induced emesis: Effects of vagal stimulation on GAD immunoreactivity

    NASA Technical Reports Server (NTRS)

    Damelio, F.; Gibbs, M. A.; Mehler, W. R.; Daunton, Nancy G.; Fox, Robert A.

    1991-01-01

    Immunocytochemical methods were employed to localize the neurotransmitter amino acid gamma-aminobutyric acid (GABA) by means of its biosynthetic enzyme glutamic acid decarboxylase (GAD) and the neuropeptide substance P in the area postrema (AP), area subpostrema (ASP), nucleus of the tractus solitarius (NTS), and gelatinous nucleus (GEL). In addition, electrical stimulation was applied to the night vagus nerve at the cervical level to assess the effects on GAD-immunoreactivity (GAR-IR). GAD-IR terminals and fibers were observed in the AP, ASP, NTS, and GEL. They showed pronounced density at the level of the ASP and gradual decrease towards the solitary complex. Nerve cells were not labelled in our preparations. Ultrastructural studies showed symmetric or asymmetric synaptic contracts between labelled terminals and non-immunoreactive dendrites, axons, or neurons. Some of the labelled terminals contained both clear- and dense-core vesicles. Our preliminary findings, after electrical stimulation of the vagus nerve, revealed a bilateral decrease of GAD-IR that was particularly evident at the level of the ASP. SP-immunoreactive (SP-IR) terminals and fibers showed varying densities in the AP, ASP, NTS, and GEL. In our preparations, the lateral sub-division of the NTS showed the greatest accumulation. The ASP showed medium density of immunoreactive varicosities and terminals and the AP and GEL displayed scattered varicose axon terminals. The electron microscopy revealed that all immunoreactive terminals contained clear-core vesicles which make symmetric or asymmetric synaptic contact with unlabelled dendrites. It is suggested that the GABAergic terminals might correspond to vagal afferent projections and that GAD/GABA and substance P might be co-localized in the same terminal allowing the possibility of a regulated release of the transmitters in relation to demands.

  16. High-yield production of vanillin from ferulic acid by a coenzyme-independent decarboxylase/oxygenase two-stage process.

    PubMed

    Furuya, Toshiki; Miura, Misa; Kuroiwa, Mari; Kino, Kuniki

    2015-05-25

    Vanillin is one of the world's most important flavor and fragrance compounds in foods and cosmetics. Recently, we demonstrated that vanillin could be produced from ferulic acid via 4-vinylguaiacol in a coenzyme-independent manner using the decarboxylase Fdc and the oxygenase Cso2. In this study, we investigated a new two-pot bioprocess for vanillin production using the whole-cell catalyst of Escherichia coli expressing Fdc in the first stage and that of E. coli expressing Cso2 in the second stage. We first optimized the second-step Cso2 reaction from 4-vinylguaiacol to vanillin, a rate-determining step for the production of vanillin. Addition of FeCl2 to the cultivation medium enhanced the activity of the resulting E. coli cells expressing Cso2, an iron protein belonging to the carotenoid cleavage oxygenase family. Furthermore, a butyl acetate-water biphasic system was effective in improving the production of vanillin. Under the optimized conditions, we attempted to produce vanillin from ferulic acid by a two-pot bioprocess on a flask scale. In the first stage, E. coli cells expressing Fdc rapidly decarboxylated ferulic acid and completely converted 75 mM of this substrate to 4-vinylguaiacol within 2 h at pH 9.0. After the first-stage reaction, cells were removed from the reaction mixture by centrifugation, and the pH of the resulting supernatant was adjusted to 10.5, the optimal pH for Cso2. This solution was subjected to the second-stage reaction. In the second stage, E. coli cells expressing Cso2 efficiently oxidized 4-vinylguaiacol to vanillin. The concentration of vanillin reached 52 mM (7.8 g L(-1)) in 24 h, which is the highest level attained to date for the biotechnological production of vanillin using recombinant cells. PMID:25765579

  17. Pyridoxine hydroxamic acids as novel HIV-integrase inhibitors.

    PubMed

    Stranix, Brent R; Wu, Jinzi J; Milot, Guy; Beaulieu, Françis; Bouchard, Jean-Emanuel; Gouveia, Kristine; Forte, André; Garde, Seema; Wang, Zhigang; Mouscadet, Jean-François; Delelis, Olivier; Xiao, Yong

    2016-02-15

    A series of pyridoxine hydroxamic acid analog bearing a 5-aryl-spacers were synthesized. Evaluation of these novel HIV integrase complex inhibitors revealed compounds with high potency against wild-type HIV virus. PMID:26826732

  18. Neuronal circuit-dependent alterations in expression of two isoforms of glutamic acid decarboxylase in the hippocampus following electroconvulsive shock: A stereology-based study.

    PubMed

    Jinno, Shozo; Kosaka, Toshio

    2009-11-01

    There is an increasing body of evidence suggesting that GABAergic dysfunction is involved in various psychiatric disorders. The goal of our study was to investigate the influences of electroconvulsive therapy (ECT), one of the most effective treatments for depression, on the GABAergic system in the hippocampus. In this stereology-based study, we identified GABAergic neurons by immunostaining for two isoforms of glutamic acid decarboxylase (GAD), GAD65, and GAD67 and estimated the expression changes induced by single or repeated electroconvulsive shock (ECS; an animal model of ECT). The numerical density (ND) of entire population of GABAergic neurons (expressing GAD65 and/or GAD67) was seldom altered by the administration of ECS. GAD67-positive (GAD67(+)) neurons were also rarely affected by ECS. On the other hand, the ND of GAD65(+) neurons was changed in a layer-specific manner. In the CA1 region, the ND of GAD65(+) neurons was increased in the strata radiatum/lacunosum-moleculare (SR/SLM) by repeated ECS. In the CA3 region, the ND of GAD65(+) neurons was decreased in the stratum oriens and SR/SLM after single ECS. The expression ratio of GAD65 in GABAergic neurons was increased specifically in layers receiving afferents from the entorhinal cortex (EC), i.e., SR/SLM of the CA1 region and molecular layer of the dentate gyrus (DG), after repeated ECS administration, whereas the expression ratio of GAD67 in GABAergic neurons was decreased in several layers by the same treatment. These results indicate that the ECS-induced changes in ND of GAD65(+) or GAD67(+) neurons were most likely due to alterations in GAD expression rather than actual increases or decreases in cell numbers. Altogether, the neuronal circuit-dependent alterations in GABA-mediated signaling may play a contributory role in the depression treatment process introduced by ECT. PMID:19283776

  19. The novel R347g pathogenic mutation of aromatic amino acid decarboxylase provides additional molecular insights into enzyme catalysis and deficiency.

    PubMed

    Montioli, Riccardo; Paiardini, Alessandro; Kurian, Manju A; Dindo, Mirco; Rossignoli, Giada; Heales, Simon J R; Pope, Simon; Voltattorni, Carla Borri; Bertoldi, Mariarita

    2016-06-01

    We report here a clinical case of a patient with a novel mutation (Arg347→Gly) in the gene encoding aromatic amino acid decarboxylase (AADC) that is associated with AADC deficiency. The variant R347G in the purified recombinant form exhibits, similarly to the pathogenic mutation R347Q previously studied, a 475-fold drop of kcat compared to the wild-type enzyme. In attempting to unravel the reason(s) for this catalytic defect, we have carried out bioinformatics analyses of the crystal structure of AADC-carbidopa complex with the modelled catalytic loop (residues 328-339). Arg347 appears to interact with Phe103, as well as with both Leu333 and Asp345. We have then prepared and characterized the artificial F103L, R347K and D345A mutants. F103L, D345A and R347K exhibit about 13-, 97-, and 345-fold kcat decrease compared to the wild-type AADC, respectively. However, unlike F103L, the R347G, R347K and R347Q mutants as well as the D345A variant appear to be more defective in catalysis than in protein folding. Moreover, the latter mutants, unlike the wild-type protein and the F103L variant, share a peculiar binding mode of dopa methyl ester consisting of formation of a quinonoid intermediate. This finding strongly suggests that their catalytic defects are mainly due to a misplacement of the substrate at the active site. Taken together, our results highlight the importance of the Arg347-Leu333-Asp345 hydrogen-bonds network in the catalysis of AADC and reveal the molecular basis for the pathogenicity of the variants R347. Following the above results, a therapeutic treatment for patients bearing the mutation R347G is proposed. PMID:26994895

  20. Harmonization of Glutamic Acid Decarboxylase and Islet Antigen-2 Autoantibody Assays for National Institute of Diabetes and Digestive and Kidney Diseases Consortia

    PubMed Central

    Bonifacio, Ezio; Yu, Liping; Williams, Alastair K.; Eisenbarth, George S.; Bingley, Polly J.; Marcovina, Santica M.; Adler, Kerstin; Ziegler, Anette G.; Mueller, Patricia W.; Schatz, Desmond A.; Krischer, Jeffrey P.; Steffes, Michael W.; Akolkar, Beena

    2010-01-01

    Background/Rationale: Autoantibodies to islet antigen-2 (IA-2A) and glutamic acid decarboxylase (GADA) are markers for diagnosis, screening, and measuring outcomes in National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK) consortia studies. A harmonization program was established to increase comparability of results within and among these studies. Methods: Large volumes of six working calibrators were prepared from pooled sera with GADA 4.8–493 World Health Organization (WHO) units/ml and IA-2A 2–235 WHO units/ml. Harmonized assay protocols for IA-2A and GADA using 35S-methionine-labelled in vitro transcribed and translated antigens were developed based on methods in use in three NIDDK laboratories. Antibody thresholds were defined using sera from patients with recent onset type 1 diabetes and healthy controls. To evaluate the impact of the harmonized assay protocol on concordance of IA-2A and GADA results, two laboratories retested stored TEDDY study sera using the harmonized assays. Results: The harmonized assays gave comparable but not identical results in the three laboratories. For IA-2A, using a common threshold of 5 DK units/ml, 549 of 550 control and patient samples were concordantly scored as positive or negative, specificity was greater than 99% with sensitivity 64% in all laboratories. For GADA, using thresholds equivalent to the 97th percentile of 974 control samples in each laboratory, 1051 (97.9%) of 1074 samples were concordant. On the retested TEDDY samples, discordance decreased from 4 to 1.8% for IA-2A (n = 604 samples; P = 0.02) and from 15.4 to 2.7% for GADA (n = 515 samples; P < 0.0001). Conclusion: Harmonization of GADA and IA-2A is feasible using large volume working calibrators and common protocols and is an effective approach to ensure consistency in autoantibody measurements. PMID:20444913

  1. Differential gene expression for glutamic acid decarboxylase and type II calcium-calmodulin-dependent protein kinase in basal ganglia, thalamus, and hypothalamus of the monkey

    SciTech Connect

    Benson, D.L.; Isackson, P.J.; Hendry, S.H.; Jones, E.G. )

    1991-06-01

    In situ hybridization histochemistry, using cRNA probes, revealed a complementarity in the distributions of cells in the basal ganglia, basal nucleus of Meynert, thalamus, hypothalamus, and rostral part of the midbrain that showed gene expression for glutamic acid decarboxylase (GAD) or the alpha-subunit of type II calcium-calmodulin-dependent protein kinase (CAM II kinase-alpha). Cells in certain nuclei such as the thalamic reticular nucleus, globus pallidus, and pars reticulata of the substantia nigra show GAD gene expression only; others in nuclei such as the basal nucleus of Meynert, medial mamillary nuclei, and ventromedial hypothalamic nuclei show CAM II kinase-alpha gene expression only. A few nuclei, for example, the pars compacta of the substantia nigra and the greater part of the subthalamic nucleus, display gene expression for neither GAD nor CAM II kinase-alpha. In other nuclei, notably those of the dorsal thalamus, and possibly in the striatum, GAD- and CAM II kinase-expressing cells appear to form two separate populations that, in most thalamic nuclei, together account for the total cell population. In situ hybridization reveals large amounts of CAM II kinase-alpha mRNA in the neuropil of most nuclei containing CAM II kinase-alpha-positive cells, suggesting its association with dendritic polyribosomes. The message may thus be translated at those sites, close to the synapses with which the protein is associated. The in situ hybridization results, coupled with those from immunocytochemical staining for CAM II kinase-alpha protein, indicate that CAM II kinase-alpha is commonly found in certain non-GABAergic afferent fiber systems but is not necessarily present in the postsynaptic cells on which they terminate. It appears to be absent from most GABAergic fiber systems but can be present in the cells on which they terminate.

  2. Evolution of Substrate Specificity within a Diverse Family of [beta/alpha]-Barrel-fold Basic Amino Acid Decarboxylases X-ray Structure Determination of Enzymes with Specificity for L-Arginine and Carboxynorspermidine

    SciTech Connect

    Deng, Xiaoyi; Lee, Jeongmi; Michael, Anthony J.; Tomchick, Diana R.; Goldsmith, Elizabeth J.; Phillips, Margaret A.

    2010-08-26

    Pyridoxal 5{prime}-phosphate (PLP)-dependent basic amino acid decarboxylases from the {beta}/{alpha}-barrel-fold class (group IV) exist in most organisms and catalyze the decarboxylation of diverse substrates, essential for polyamine and lysine biosynthesis. Herein we describe the first x-ray structure determination of bacterial biosynthetic arginine decarboxylase (ADC) and carboxynorspermidine decarboxylase (CANSDC) to 2.3- and 2.0-{angstrom} resolution, solved as product complexes with agmatine and norspermidine. Despite low overall sequence identity, the monomeric and dimeric structures are similar to other enzymes in the family, with the active sites formed between the {beta}/{alpha}-barrel domain of one subunit and the {beta}-barrel of the other. ADC contains both a unique interdomain insertion (4-helical bundle) and a C-terminal extension (3-helical bundle) and it packs as a tetramer in the asymmetric unit with the insertions forming part of the dimer and tetramer interfaces. Analytical ultracentrifugation studies confirmed that the ADC solution structure is a tetramer. Specificity for different basic amino acids appears to arise primarily from changes in the position of, and amino acid replacements in, a helix in the {beta}-barrel domain we refer to as the 'specificity helix.' Additionally, in CANSDC a key acidic residue that interacts with the distal amino group of other substrates is replaced by Leu{sup 314}, which interacts with the aliphatic portion of norspermidine. Neither product, agmatine in ADC nor norspermidine in CANSDC, form a Schiff base to pyridoxal 5{prime}-phosphate, suggesting that the product complexes may promote product release by slowing the back reaction. These studies provide insight into the structural basis for the evolution of novel function within a common structural-fold.

  3. Evaluation of oxalate decarboxylase and oxalate oxidase for industrial applications.

    PubMed

    Cassland, Pierre; Sjöde, Anders; Winestrand, Sandra; Jönsson, Leif J; Nilvebrant, Nils-Olof

    2010-05-01

    Increased recirculation of process water has given rise to problems with formation of calcium oxalate incrusts (scaling) in the pulp and paper industry and in forest biorefineries. The potential in using oxalate decarboxylase from Aspergillus niger for oxalic acid removal in industrial bleaching plant filtrates containing oxalic acid was examined and compared with barley oxalate oxidase. Ten different filtrates from chemical pulping were selected for the evaluation. Oxalate decarboxylase degraded oxalic acid faster than oxalate oxidase in eight of the filtrates, while oxalate oxidase performed better in one filtrate. One of the filtrates inhibited both enzymes. The potential inhibitory effect of selected compounds on the enzymatic activity was tested. Oxalate decarboxylase was more sensitive than oxalate oxidase to hydrogen peroxide. Oxalate decarboxylase was not as sensitive to chlorate and chlorite as oxalate oxidase. Up to 4 mM chlorate ions, the highest concentration tested, had no inhibitory effect on oxalate decarboxylase. Analysis of the filtrates suggests that high concentrations of chlorate present in some of the filtrates were responsible for the higher sensitivity of oxalate oxidase in these filtrates. Oxalate decarboxylase was thus a better choice than oxalate oxidase for treatment of filtrates from chlorine dioxide bleaching. PMID:19763895

  4. Converting maslinic acid into an effective inhibitor of acylcholinesterases.

    PubMed

    Schwarz, Stefan; Loesche, Anne; Lucas, Susana Dias; Sommerwerk, Sven; Serbian, Immo; Siewert, Bianka; Pianowski, Elke; Csuk, René

    2015-10-20

    During the last decade, maslinic acid has been evaluated for many biological properties, e.g. as an anti-tumor or an anti-viral agent but also as a nutraceutical. The potential of maslinic acid and related derivatives to act as inhibitors of acetyl- or butyryl-cholinesterase was examined in this communication in more detail. Cholinesterases do still represent an interesting group of target enzymes with respect to the investigation and treatment of the Alzheimer's disease and other dementia illnesses as well. Although other triterpenoic acids have successfully been tested for their ability to act as inhibitors of cholinesterases, up to now maslinic acid has not been part of such studies. For this reason, three series of maslinic acid derivatives possessing modifications at different centers were synthesized and subjected to Ellman's assay to determine their inhibitory strength and type of inhibitory action. While parent compound maslinic acid was no inhibitor in these assays, some of the compounds exhibited an inhibition of acetylcholinesterase in the single-digit micro-molar range. Two compounds were identified as inhibitors of butyrylcholinesterase showing inhibition constants comparable to those of galantamine, a drug often used in the treatment of Alzheimer's disease. Furthermore, additional selectivity as well as cytotoxicity studies were performed underlining the potential of several derivatives and qualifying them for further investigations. Docking studies revealed that the different kinetic behavior within the same compound series may be explained by the ability of the compounds to enter the active site gorge of AChE. PMID:26383128

  5. The preparation and characterization of an immobilized l-glutamic decarboxylase and its application for determination of l-glutamic acid.

    PubMed

    Ling; Wu; Wang; Wang; Song

    2000-10-01

    This paper is to study the preparation and characterization of an immobilized L-glutamic decarboxylase (GDC) and develop a sensitive method for the determination of L-glutamate using a new biosensor, which consists of an enzyme column reactor of GDC immobilized on a novel ion exchange resin (carboxymethyl-copolymer of allyl dextran and N.N'-methylene-bisacrylamide CM-CADB) and ion analyzer coupled with a CO(2) electrode. The conditions for the enzyme immobilization were optimized by the parameters: buffer composition and concentration, adsorption equilibration time, amount of enzyme, temperature, ionic strength and pH. The dynamic response of Na(2)HPO(4)-citric acid buffer system selected is much better than that of the others, 0.10 M HAc-0.10 M NaAc and 0.10 M sodium citrate-0.10 M citric acid. The initial rate of the enzyme reaction v(0) in this buffer system is 1.76 mol. l(-1) min(-1), moreover, the rate of the enzyme reaction appears linear in the first 4 min. The optimum adsorption equilibrium time is around 6 h. The amount of enzyme adsorbed on CM-CADB resin affects the response to substrate L-glutamic acid, the widest range of linearity is obtained with over 30 mg (GDC)/g(resin). The GDC activity immobilized on CM-CADB reaches a maximum when the immobilization temperature was kept around 40 degrees C. pH was kept at 4.4 when measuring the activity of the immobilized GDC. No variation of the activity of immobilized GDC is observed when the capacity is over 2.5 meq/g.(CM-CADB resin). The properties of the immobilized enzyme on CM-CADB were characterized. No significant improvement can be achieved when the substrate concentration exceeds 12.00 mmol/l, where the activity of immobilized GDC is equal to 1.58 mmol/l.min.g. The optimum pH is found to be 5.2, which changes 0.2 unit, comparing with that of the free GDC (5.0). The optimum temperature is found to be around 48 degrees C, which is lower than that of free GDC (55 degrees C). The critical temperature of the

  6. Inactivation of 3-(3,4-dihydroxyphenyl)alanine decarboxylase by 2-(fluoromethyl)-3-(3,4-dihydroxyphenyl)alanine.

    PubMed

    Maycock, A L; Aster, S D; Patchett, A A

    1980-02-19

    2-(Fluoromethyl)-3-(3,4-dihydroxyphenyl)alanine [alpha-FM-Dopa (I)] causes rapid, time-dependent, stereospecific, and irreversible inhibition of hog kidney aromatic amino acid (Dopa) decarboxylase. The inactivation occurs with loss of both the carboxyl carbon and fluoride from I and results in the stoichimetric formation of a covalent enzyme-inhibitor adduct. The data are consistent with I being a suicide inactivator of the enzyme, and a plausible mechanism for the inactivation process is presented. The inactivation is highly efficient in that there is essentially no enzymatic turnover of I to produce the corresponding amine, 1-(fluoromethyl)-2-(3,4-dihydroxyphenyl)ethylamine [alpha-FM-dopamine (II)]. Amine II is also a potent inactivator of the enzyme. In vivo compound I is found to inactivate both brain and peripheral (liver) Dopa decarboxylase activity. The possible significance of these data with respect to the known antihypertensive effect of I is discussed. PMID:7356954

  7. Clinical and Genetic Characteristics of Non-Insulin-Requiring Glutamic Acid Decarboxylase (GAD) Autoantibody-Positive Diabetes: A Nationwide Survey in Japan

    PubMed Central

    Yasui, Junichi; Kawasaki, Eiji; Tanaka, Shoichiro; Awata, Takuya; Ikegami, Hiroshi; Imagawa, Akihisa; Uchigata, Yasuko; Osawa, Haruhiko; Kajio, Hiroshi; Kawabata, Yumiko; Shimada, Akira; Takahashi, Kazuma; Yasuda, Kazuki; Yasuda, Hisafumi; Hanafusa, Toshiaki; Kobayashi, Tetsuro

    2016-01-01

    Aims Glutamic acid decarboxylase autoantibodies (GADAb) differentiate slowly progressive insulin-dependent (type 1) diabetes mellitus (SPIDDM) from phenotypic type 2 diabetes, but many GADAb-positive patients with diabetes do not progress to insulin-requiring diabetes. To characterize GADAb-positive patients with adult-onset diabetes who do not require insulin therapy for >5 years (NIR-SPIDDM), we conducted a nationwide cross-sectional survey in Japan. Methods We collected 82 GADAb-positive patients who did not require insulin therapy for >5 years (NIR-SPIDDM) and compared them with 63 patients with insulin-requiring SPIDDM (IR-SPIDDM). Clinical and biochemical characteristics, HLA-DRB1-DQB1 haplotypes, and predictive markers for progression to insulin therapy were investigated. Results Compared with the IR-SPIDDM group, the NIR-SPIDDM patients showed later diabetes onset, higher body mass index, longer duration before diagnosis, and less frequent hyperglycemic symptoms at onset. In addition, C-peptide, LDL-cholesterol, and TG were significantly higher in the NIR-SPIDDM compared to IR-SPIDDM patients. The NIR-SPIDDM group had lower frequency of susceptible HLA-DRB1*04:05-DQB1*04:01 and a higher frequency of resistant HLA-DRB1*15:01-DQB1*06:02 haplotype compared to IR-SPIDDM. A multivariable analysis showed that age at diabetes onset (OR = 0.82), duration before diagnosis of GADAb-positive diabetes (OR = 0.82), higher GADAb level (≥10.0 U/ml) (OR = 20.41), and fasting C-peptide at diagnosis (OR = 0.07) were independent predictive markers for progression to insulin-requiring diabetes. An ROC curve analysis showed that the optimal cut-off points for discriminating two groups was the GADAb level of 13.6 U/ml, age of diabetes onset of 47 years, duration before diagnosis of 5 years, and fasting C-peptide of 0.65 ng/ml. Conclusions Clinical, biochemical and genetic characteristics of patients with NIR-SPIDDM are different from those of IR-SPIDDM patients. Age of

  8. Tyrosine hydroxylase- and/or aromatic L-amino acid decarboxylase-expressing neurons in the rat arcuate nucleus: ontogenesis and functional significance.

    PubMed

    Ugrumov, M; Melnikova, V; Ershov, P; Balan, I; Calas, A

    2002-07-01

    This study has evaluated in vivo, ex vivo and in vitro the ontogenesis and functional significance of the neurons of the arcuate nucleus (AN) expressing either individual enzymes of dopamine (DA) synthesis, tyrosine hydroxylase (TH) or aromatic L-amino acid decarboxylase (AADC) as well as both of them in rats from the 17th embryonic day (E) till adulthood. Immunocytochemistry, image analysis, confocal microscopy, high performance liquid chromatography with electrochemical detection and radioimmunoassay were used to solve this problem. Monoenzymatic TH-containing neurons were initially observed on E18 located in the ventrolateral AN whereas the neurons expressing only AADC or both AADC and TH first appeared on E20 in the dorsomedial AN. On E21, the monoenzymatic TH- or AADC-expressing neurons comprised more than 99% of the whole neuron population expressing the DA-synthesizing enzymes. In spite of an extremely small number (<1%) of the neurons expressing both enzymes (DArgic neurons), the dissected AN (ex vivo) and its primary cell culture (in vitro) contained a surprisingly high amount of DA and L-dihydroxyphenylalanine (L-DOPA) which were released in response to membrane depolarization. Furthermore, DA production in the AN of fetuses occurred to be sufficient to provide an inhibitory control of prolactin secretion, as in adults. The above data suggest that DA could be synthesized, at least in the AN of fetuses, by monoenzymatic neurons containing either TH or AADC, in co-operation. This hypothesis may be extended to adult animals as their AN contained the same populations of the neurons expressing DA-synthesizing enzymes as in fetuses though the proportion of true DArgic neurons increased up to 38%. During ontogenesis, the monoenzymatic TH- and AADC-containing neurons established axosomatic and axo-axonal junctions that might facilitate the L-DOPA transport from the former to the latter. Moreover, the monoenzymatic AADC-expressing neurons project their axons to

  9. Serum titres of anti-glutamic acid decarboxylase-65 and anti-IA-2 autoantibodies are associated with different immunoregulatory milieu in newly diagnosed type 1 diabetes patients.

    PubMed

    Gabbay, M Andrade Lima; Sato, M N; Duarte, A J S; Dib, S A

    2012-04-01

    Several studies correlated genetic background and pancreatic islet-cell autoantibody status (type and number) in type 1A diabetes mellitus (T1AD), but there are no data evaluating the relationship among these markers with serum cytokines, regulatory T cells and β cell function. This characterization has a potential importance with regard to T1AD patients' stratification and follow-up in therapeutic prevention. In this study we showed that peripheral sera cytokines [interleukin (IL)-12, IL-6, II-1β, tumour necrosis factor (TNF)-α, IL-10] and chemokines (CXCL10, CXCL8, CXCL9, CCL2) measured were significantly higher in newly diagnosed T1AD patients when compared to healthy controls (P < 0·001). Among T1AD, we found a positive correlation between CXCL10 and CCL-2 (r = 0·80; P = 0·000), IL-8 and TNF-α (r = 0·60; P = 0·000); IL-8 and IL-12 (r = 0·57; P = 0·001) and TNF-α and IL-12 (r = 0·93; P = 0·000). Glutamic acid decarboxylase-65 (GAD-65) autoantibodies (GADA) were associated negatively with CXCL10 (r = -0·45; P = 0·011) and CCL2 (r = -0·65; P = 0·000), while IA-2A showed a negative correlation with IL-10 (r = -0·38; P = 0·027). Human leucocyte antigen (HLA) DR3, DR4 or DR3/DR4 and PTPN22 polymorphism did not show any association with pancreatic islet cell antibodies or cytokines studied. In summary, our results revealed that T1AD have a proinflammatory cytokine profile compared to healthy controls and that IA-2A sera titres seem to be associated with a more inflammatory peripheral cytokine/chemokine profile than GADA. A confirmation of these data in the pre-T1AD phase could help to explain the mechanistic of the well-known role of IA-2A as a more specific marker of beta-cell damage than GADA during the natural history of T1AD. PMID:22385239

  10. Interaction of silicic acid with sulfurous acid scale inhibitor

    SciTech Connect

    Gallup, D.L.

    1997-12-31

    The solubility of amorphous silica and the inhibition of silica polymerization in the presence of sulfurous acid and sulfite salts has been investigated to 260{degrees}C. Investigations of inhibition of silica scaling from geothermal brines by sulfurous acid have produced unusual results. Bisulfite/sulfite increases amorphous silica solubility by {open_quotes}salting in{close_quotes} effects resulting from apparent complexation. Silica-sulfite complexes are postulated to form via hydrogen bonding, and appear to be much stronger than silica-sulfate complexes. Treatment of brines with sulfurous acid inhibits silica scaling by (1) retarding the kinetics of silicic acid polymerization, and (2) forming soluble sulfito-silicate complexes. Sulfurous acid offers several advantages over sulfuric acid in controlling scale deposition-reduced corrosion potential, reduced by-product scale formation potential, oxygen scavenging and inhibition of certain metal silicate scales.

  11. Polyamines are Inhibitors of Gastric Acid Secretion

    NASA Astrophysics Data System (ADS)

    Ray, Tushar K.; Nandi, Jyotirmoy; Pidhorodeckyj, Nykolai; Meng-Ai, Zhou

    1982-03-01

    The naturally occurring organic polycations such as spermine and spermidine inhibit histamine-stimulated gastric acid secretion by bullfrog gastric mucosa in vitro; spermine is much more potent than spermidine. Unlike the H2 receptor antagonists, the polyamines are completely ineffective from the nutrient side and are effective only from the secretory side of the chambered mucosa. The polyamine effects could be reversed by increasing K+ concentration in the secretory solution. Studies with isolated gastric microsomal vesicles demonstrate that the polyamines do not inhibit the gastric H+,K+-ATPase but greatly decrease the ATPase-mediated uptake of H+ under appropriate conditions. For the latter effects the presence of polyamine within the vesicle interior was found to be essential. Our data strongly suggest an uncoupling of the gastric H+,K+-ATPase system by the polyamines. The therapeutic potential of these and similar compounds in the treatment of hyperacidity and peptic ulcer is discussed.

  12. Identification and characterization of phenylpyruvate decarboxylase genes in Saccharomyces cerevisiae.

    PubMed

    Vuralhan, Zeynep; Morais, Marcos A; Tai, Siew-Leng; Piper, Matthew D W; Pronk, Jack T

    2003-08-01

    Catabolism of amino acids via the Ehrlich pathway involves transamination to the corresponding alpha-keto acids, followed by decarboxylation to an aldehyde and then reduction to an alcohol. Alternatively, the aldehyde may be oxidized to an acid. This pathway is functional in Saccharomyces cerevisiae, since during growth in glucose-limited chemostat cultures with phenylalanine as the sole nitrogen source, phenylethanol and phenylacetate were produced in quantities that accounted for all of the phenylalanine consumed. Our objective was to identify the structural gene(s) required for the decarboxylation of phenylpyruvate to phenylacetaldehyde, the first specific step in the Ehrlich pathway. S. cerevisiae possesses five candidate genes with sequence similarity to genes encoding thiamine diphosphate-dependent decarboxylases that could encode this activity: YDR380w/ARO10, YDL080C/THI3, PDC1, PDC5, and PDC6. Phenylpyruvate decarboxylase activity was present in cultures grown with phenylalanine as the sole nitrogen source but was absent from ammonia-grown cultures. Furthermore, the transcript level of one candidate gene (ARO10) increased 30-fold when phenylalanine replaced ammonia as the sole nitrogen source. Analyses of phenylalanine catabolite production and phenylpyruvate decarboxylase enzyme assays indicated that ARO10 was sufficient to encode phenylpyruvate decarboxylase activity in the absence of the four other candidate genes. There was also an alternative activity with a higher capacity but lower affinity for phenylpyruvate. The candidate gene THI3 did not itself encode an active phenylpyruvate decarboxylase but was required along with one or more pyruvate decarboxylase genes (PDC1, PDC5, and PDC6) for the alternative activity. The K(m) and V(max) values of the two activities differed, showing that Aro10p is the physiologically relevant phenylpyruvate decarboxylase in wild-type cells. Modifications to this gene could therefore be important for metabolic engineering

  13. Design and synthesis of boronic acid inhibitors of endothelial lipase.

    PubMed

    O'Connell, Daniel P; LeBlanc, Daniel F; Cromley, Debra; Billheimer, Jeffrey; Rader, Daniel J; Bachovchin, William W

    2012-02-01

    Endothelial lipase (EL) and lipoprotein lipase (LPL) are homologous lipases that act on plasma lipoproteins. EL is predominantly a phospholipase and appears to be a key regulator of plasma HDL-C. LPL is mainly a triglyceride lipase regulating (V)LDL levels. The existing biological data indicate that inhibitors selective for EL over LPL should have anti-atherogenic activity, mainly through increasing plasma HDL-C levels. We report here the synthesis of alkyl, aryl, or acyl-substituted phenylboronic acids that inhibit EL. Many of the inhibitors evaluated proved to be nearly equally potent against both EL and LPL, but several exhibited moderate to good selectivity for EL. PMID:22225633

  14. Vector-mediated chromosomal integration of the glutamate decarboxylase gene in streptococcus thermophilus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    The integrative vector pINTRS was used to transfer glutamate decarboxylase (GAD) activity to Streptococcus thermophilus ST128, thus allowing for the production of '-aminobutyric acid (GABA). In pINTRS, the gene encoding glutamate decarboxylase, gadB, was flanked by DNA fragments homologous to a S. ...

  15. Discovery of potent wall teichoic acid early stage inhibitors.

    PubMed

    Labroli, Marc A; Caldwell, John P; Yang, Christine; Lee, Sang Ho; Wang, Hao; Koseoglu, Sandra; Mann, Paul; Yang, Shu-Wei; Xiao, Jing; Garlisi, Charles G; Tan, Christopher; Roemer, Terry; Su, Jing

    2016-08-15

    The widespread emergence of methicillin-resistant Staphylococcus aureus (MRSA) has dramatically eroded the efficacy of current β-lactam antibiotics and created an urgent need for novel treatment options. Using an S. aureus phenotypic screening strategy, we have identified small molecule early stage wall teichoic acid (WTA) pathway-specific inhibitors predicted to be chemically synergistic with β-lactams. These previously disclosed inhibitors, termed tarocins, demonstrate by genetic and biochemical means inhibition of TarO, the first step in WTA biosynthesis. Tarocins demonstrate potent bactericidal synergy in combination with broad spectrum β-lactam antibiotics across diverse clinical isolates of methicillin-resistant Staphylococci. The synthesis and structure-activity relationships (SAR) of a tarocin series will be detailed. Tarocins and other WTA inhibitors may provide a rational strategy to develop Gram-positive bactericidal β-lactam combination agents active against methicillin-resistant Staphylococci. PMID:27436582

  16. Salicylic Acid Inhibits Synthesis of Proteinase Inhibitors in Tomato Leaves Induced by Systemin and Jasmonic Acid.

    PubMed Central

    Doares, S. H.; Narvaez-Vasquez, J.; Conconi, A.; Ryan, C. A.

    1995-01-01

    Salicylic acid (SA) and acetylsalicylic acid (ASA), previously shown to inhibit proteinase inhibitor synthesis induced by wounding, oligouronides (H.M. Doherty, R.R. Selvendran, D.J. Bowles [1988] Physiol Mol Plant Pathol 33: 377-384), and linolenic acid (H. Pena-Cortes, T. Albrecht, S. Prat, E.W. Weiler, L. Willmitzer [1993] Planta 191: 123-128), are shown here to be potent inhibitors of systemin-induced and jasmonic acid (JA)-induced synthesis of proteinase inhibitor mRNAs and proteins. The inhibition by SA and ASA of proteinase inhibitor synthesis induced by systemin and JA, as well as by wounding and oligosaccharide elicitors, provides further evidence that both oligosaccharide and polypeptide inducer molecules utilize the octadecanoid pathway to signal the activation of proteinase inhibitor genes. Tomato (Lycopersicon esculentum) leaves were pulse labeled with [35S]methionine, followed by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, and the inhibitory effects of SA are shown to be specific for the synthesis of a small number of JA-inducible proteins that includes the proteinase inhibitors. Previous results have shown that SA inhibits the conversion of 13S-hydroperoxy linolenic acid to 12-oxo-phytodienoic acid, thereby inhibiting the signaling pathway by blocking synthesis of JA. Here we report that the inhibition of synthesis of proteinase inhibitor proteins and mRNAs by SA in both light and darkness also occurs at a step in the signal transduction pathway, after JA synthesis but preceding transcription of the inhibitor genes. PMID:12228577

  17. Tanzawaic Acids, a Chemically Novel Set of Bacterial Conjugation Inhibitors

    PubMed Central

    Getino, María; Fernández-López, Raúl; Palencia-Gándara, Carolina; Campos-Gómez, Javier; Sánchez-López, Jose M.; Martínez, Marta; Fernández, Antonio; de la Cruz, Fernando

    2016-01-01

    Bacterial conjugation is the main mechanism for the dissemination of multiple antibiotic resistance in human pathogens. This dissemination could be controlled by molecules that interfere with the conjugation process. A search for conjugation inhibitors among a collection of 1,632 natural compounds, identified tanzawaic acids A and B as best hits. They specially inhibited IncW and IncFII conjugative systems, including plasmids mobilized by them. Plasmids belonging to IncFI, IncI, IncL/M, IncX and IncH incompatibility groups were targeted to a lesser extent, whereas IncN and IncP plasmids were unaffected. Tanzawaic acids showed reduced toxicity in bacterial, fungal or human cells, when compared to synthetic conjugation inhibitors, opening the possibility of their deployment in complex environments, including natural settings relevant for antibiotic resistance dissemination. PMID:26812051

  18. Functional analysis and transcriptional regulation of two orthologs of ARO10, encoding broad-substrate-specificity 2-oxo-acid decarboxylases, in the brewing yeast Saccharomyces pastorianus CBS1483.

    PubMed

    Bolat, Irina; Romagnoli, Gabriele; Zhu, Feibai; Pronk, Jack T; Daran, Jean-Marc

    2013-09-01

    The hybrid genomes of Saccharomyces pastorianus consist of subgenomes similar to those of S. cerevisiae and S. eubayanus, and impact of the genome structure on flavour production and its regulation is poorly understood. This study focuses on ARO10, a 2-oxo-acid decarboxylase involved in production of higher alcohols. In S. pastorianus CBS1483, four ARO10 copies were identified, three resembled S. cerevisiae ARO10 and one S. eubayanus ARO10. Substrate specificities of lager strain (Lg)ScAro10 and LgSeubAro10 were compared by individually expressing them in a pdc1Δ-pdc5Δ-pdc6Δ-aro10Δ-thi3Δ S. cerevisiae strain. Both isoenzymes catalysed decarboxylation of the 2-oxo-acids derived from branched-chain, sulphur-containing amino acids and preferably phenylpyruvate. Expression of both alleles was induced by phenylalanine, however in contrast to the S. cerevisiae strain, the two genes were not induced by leucine. Additionally, LgSeubARO10 showed higher basal expression levels during growth with ammonia. ARO80, which encodes ARO10 transcriptional activator, is located on CHRIV and counts three Sc-like and one Seub-like copies. Deletion of LgSeubARO80 did not affect LgSeubARO10 phenylalanine induction, revealing 'trans' regulation across the subgenomes. ARO10 transcript levels showed a poor correlation with decarboxylase activities. These results provide insights into flavour formation in S. pastorianus and illustrate the complexity of functional characterization in aneuploid strains. PMID:23692465

  19. Isolation and characterization of the dopa decarboxylase gene of Drosophila melanogaster.

    PubMed Central

    Hirsh, J; Davidson, N

    1981-01-01

    We have isolated chromosomal deoxyribonucleic acid clones containing the Drosophila dopa decarboxylase gene. We describe an isolation procedure which can be applied to other nonabundantly expressed Drosophila genes. The dopa decarboxylase gene lies within or very near polytene chromosome band 37C1-2. The gene is interrupted by at least one intron, and the primary mode of regulation is pretranslational. At least two additional sequences hybridized by in vivo ribonucleic acid-derived probes are found within a 35-kilobase region surrounding the gene. The developmental profile of ribonucleic acid transcribed from one of these regions differs from that of the dopa decarboxylase transcript. Images PMID:6086012

  20. Nitroaromatic amino acids as inhibitors of neuronal nitric oxide synthase.

    PubMed

    Cowart, M; Kowaluk, E A; Daanen, J F; Kohlhaas, K L; Alexander, K M; Wagenaar, F L; Kerwin, J F

    1998-07-01

    Nitric oxide (NO.) is an important biomodulator of many physiological processes. The inhibition of inappropriate production of NO. by the isoforms of nitric oxide synthase (NOS) has been proposed as a therapeutic approach for the treatment of stroke, inflammation, and other processes. In this study, certain 2-nitroaryl-substituted amino acid analogues were discovered to inhibit NOS. Analogues bearing a 5-methyl substituent on the aromatic ring demonstrated maximal inhibitory potency. For two selected inhibitors, investigation of the kinetics of the enzyme showed the inhibition to be competitive with l-arginine. Additionally, functional NOS inhibition in tissue preparations was demonstrated. PMID:9651169

  1. Mechanisms of corrosion inhibitors used in acidizing wells

    SciTech Connect

    Frenier, W.W.; Growcock, F.B.; Lopp, V.R. )

    1988-11-01

    Two model compounds, n-dodecylpyridinium bromide (n-DDPB) and 1-octyn-3-ol, were tested in HCL acid as inhibitors for J55 oilfield steel. This paper describes the kinetic and chemical analyses conducted to arrive at inhibition mechanisms for these model compounds. These studies show that the pyridinium forms a weak bond with the chloride-covered surface and is sensitive to temperature and (HCl). Octynol, however, chemisorbs and produces a film that contains a reaction product of the acetylenic alcohol. This film is quite insensitive to changes in temperature and (HCl).

  2. Arginine decarboxylase as the source of putrescine for tobacco alkaloids

    NASA Technical Reports Server (NTRS)

    Tiburcio, A. F.; Galston, A. W.

    1986-01-01

    The putrescine which forms a part of nicotine and other pyrrolidine alkaloids is generally assumed to arise through the action of ornithine decarboxylase (ODC). However, we have previously noted that changes in the activity of arginine decarboxylase (ADC), an alternate source of putrescine, parallel changes in tissue alkaloids, while changes in ODC activity do not. This led us to undertake experiments to permit discrimination between ADC and ODC as enzymatic sources of putrescine destined for alkaloids. Two kinds of evidence presented here support a major role for ADC in the generation of putrescine going into alkaloids: (a) A specific 'suicide inhibitor' of ADC effectively inhibits the biosynthesis of nicotine and nornicotine in tobacco callus, while the analogous inhibitor of ODC is less effective, and (b) the flow of 14C from uniformly labelled arginine into nicotine is much more efficient than that from ornithine.

  3. Amino derivatives of glycyrrhetinic acid as potential inhibitors of cholinesterases.

    PubMed

    Schwarz, Stefan; Lucas, Susana Dias; Sommerwerk, Sven; Csuk, René

    2014-07-01

    The development of remedies against the Alzheimer's disease (AD) is one of the biggest challenges in medicinal chemistry nowadays. Although not completely understood, there are several strategies fighting this disease or at least bringing some relief. During the progress of AD, the level of acetylcholine (ACh) decreases; hence, a therapy using inhibitors should be of some benefit to the patients. Drugs presently used for the treatment of AD inhibit the two ACh controlling enzymes, acetylcholinesterase as well as butyrylcholinesterase; hence, the design of selective inhibitors is called for. Glycyrrhetinic acid seems to be an interesting starting point for the development of selective inhibitors. Although its glycon, glycyrrhetinic acid is known for being an AChE activator, several derivatives, altered in position C-3 and C-30, exhibited remarkable inhibition constants in micro-molar range. Furthermore, five representative compounds were subjected to three more enzyme assays (on carbonic anhydrase II, papain and the lipase from Candida antarctica) to gain information about the selectivity of the compounds in comparison to other enzymes. In addition, photometric sulforhodamine B assays using murine embryonic fibroblasts (NiH 3T3) were performed to study the cytotoxicity of these compounds. Two derivatives, bearing either a 1,3-diaminopropyl or a 1H-benzotriazolyl residue, showed a BChE selective inhibition in the single-digit micro-molar range without being cytotoxic up to 30μM. In silico molecular docking studies on the active sites of AChE and BChE were performed to gain a molecular insight into the mode of action of these compounds and to explain the pronounced selectivity for BChE. PMID:24853320

  4. Total synthesis of the squalene synthase inhibitor zaragozic acid C.

    PubMed

    Nakamura, Seiichi

    2005-01-01

    Zaragozic acids and squalestatins were documented by Merck, Glaxo, and Tokyo Noko University/Mitsubishi Kasei Corporation as part of a program aimed at identifying novel inhibitors of squalene synthase, as well as farnesyl transferase. These natural products have attracted considerable attention from numerous synthetic chemists because of their therapeutic potential and novel architecture. This review highlights our total syntheses of zaragozic acid C by two convergent strategies. The key steps in our first-generation synthesis involve 1) simultaneous creation of the C4 and C5 quaternary stereocenters through the Sn(OTf)2-promoted aldol coupling reaction between the alpha-keto ester and silyl ketene thioacetal derived from L- and D-tartaric acids, respectively; and 2) construction of the bicyclic core structure via acid-catalyzed internal ketalization under kinetically controlled conditions. The second-generation strategy relies on a tandem carbonyl ylide formation/1,3-dipolar cycloaddition approach and features elongation of the C1 alkyl side chain through an olefin cross-metathesis as well as high convergency and flexibility. PMID:15635219

  5. cis-Cinnamic acid selective suppressors distinct from auxin inhibitors.

    PubMed

    Okuda, Katsuhiro; Nishikawa, Keisuke; Fukuda, Hiroshi; Fujii, Yoshiharu; Shindo, Mitsuru

    2014-01-01

    The activity of cis-cinnamic acid (cis-CA), one of the allelochemicals, in plants is very similar to that of indole-3-acetic acid (IAA), a natural auxin, and thus cis-CA has long been believed to be an analog of auxin. We have reported some structure-activity relationships studies by synthesizing over 250 cis-CA derivatives and estimating their inhibitory activities on root growth inhibition in lettuce. In this study, the compounds that showed low- or no-activity on root growth inhibition were recruited as candidates suppressors against cis-CA and/or auxin and tested for their activity. In the presence of cis-CA, lettuce root growth was inhibited; however, the addition of some cis-CA derivatives restored control-level root growth. Four compounds, (Z)-3-(4-isopropylphenyl)acrylic acid, (Z)-3-(3-butoxyphenyl)acrylic acid, (Z)-3-[3-(pentyloxy)phenyl]acrylic acid, and (Z)-3-(naphthalen-1-yl)acrylic acid were selected as candidates for a cis-CA selective suppressor they allowed the recovery of root growth from inhibition by cis-CA treatment without any effects on the IAA-induced effect or elongating activity by themselves. Three candidates significantly ameliorated the root shortening by the potent inhibitor derived from cis-CA. In brief, we have found some cis-CA selective suppressors which have never been reported from inactive cis-CA derivatives for root growth inhibition. cis-CA selective suppressors will play an important role in elucidating the mechanism of plant growth regulation. PMID:24881667

  6. Three Distinct Glutamate Decarboxylase Genes in Vertebrates

    PubMed Central

    Grone, Brian P.; Maruska, Karen P.

    2016-01-01

    Gamma-aminobutyric acid (GABA) is a widely conserved signaling molecule that in animals has been adapted as a neurotransmitter. GABA is synthesized from the amino acid glutamate by the action of glutamate decarboxylases (GADs). Two vertebrate genes, GAD1 and GAD2, encode distinct GAD proteins: GAD67 and GAD65, respectively. We have identified a third vertebrate GAD gene, GAD3. This gene is conserved in fishes as well as tetrapods. We analyzed protein sequence, gene structure, synteny, and phylogenetics to identify GAD3 as a homolog of GAD1 and GAD2. Interestingly, we found that GAD3 was lost in the hominid lineage. Because of the importance of GABA as a neurotransmitter, GAD3 may play important roles in vertebrate nervous systems. PMID:27461130

  7. Molecular assembly for high-performance bivalent nucleic acid inhibitor.

    PubMed

    Kim, Youngmi; Cao, Zehui; Tan, Weihong

    2008-04-15

    It is theorized that multivalent interaction can result in better affinity and selectivity than monovalent interaction in the design of high-performance ligands. Accordingly, biomolecular engineers are increasingly taking advantage of multivalent interactions to fabricate novel molecular assemblies, resulting in new functions for ligands or enhanced performance of existing ligands. Substantial efforts have been expended in using small molecules or epitopes of antibodies for designing multifunctional or better-performing ligands. However, few attempts to use nucleic acid aptamers as functional domains have been reported. In this study, we explore the design of bivalent nucleic acid ligands by using thrombin and its aptamers as the model by which to evaluate its functions. By assembling two thrombin-binding aptamers with optimized design parameters, this assembly has resulted in the successful development of a nucleic acid-based high-performance bivalent protein inhibitor. Our experimentation proved (i) that the simultaneous binding of two aptamers after linkage achieved 16.6-fold better inhibition efficiency than binding of the monovalent ligand and (ii) that such an improvement originated from changes in the kinetics of the binding interactions, with a k(off) rate approximately 1/50 as fast. In addition, the newly generated aptamer assembly is an excellent anticoagulant reagent when tested with different samples. Because this optimized ligand design offers a simple and noninvasive means of accomplishing higher performance from known functional aptamers, it holds promise as a potent antithrombin agent in the treatment of various diseases related to abnormal thrombin activities. PMID:18398007

  8. Identification of Bidentate Salicylic Acid Inhibitors of PTP1B.

    PubMed

    Haftchenary, Sina; Jouk, Andriana O; Aubry, Isabelle; Lewis, Andrew M; Landry, Melissa; Ball, Daniel P; Shouksmith, Andrew E; Collins, Catherine V; Tremblay, Michel L; Gunning, Patrick T

    2015-09-10

    PTP1B is a master regulator in the insulin and leptin metabolic pathways. Hyper-activated PTP1B results in insulin resistance and is viewed as a key factor in the onset of type II diabetes and obesity. Moreover, inhibition of PTP1B expression in cancer cells dramatically inhibits cell growth in vitro and in vivo. Herein, we report the computationally guided optimization of a salicylic acid-based PTP1B inhibitor 6, identifying new and more potent bidentate PTP1B inhibitors, such as 20h, which exhibited a > 4-fold improvement in activity. In CHO-IR cells, 20f, 20h, and 20j suppressed PTP1B activity and restored insulin receptor phosphorylation levels. Notably, 20f, which displayed a 5-fold selectivity for PTP1B over the closely related PTPσ protein, showed no inhibition of PTP-LAR, PRL2 A/S, MKPX, or papain. Finally, 20i and 20j displayed nanomolar inhibition of PTPσ, representing interesting lead compounds for further investigation. PMID:26396684

  9. Sulfonyl fluoride inhibitors of fatty acid amide hydrolase.

    PubMed

    Alapafuja, Shakiru O; Nikas, Spyros P; Bharathan, Indu T; Shukla, Vidyanand G; Nasr, Mahmoud L; Bowman, Anna L; Zvonok, Nikolai; Li, Jing; Shi, Xiaomeng; Engen, John R; Makriyannis, Alexandros

    2012-11-26

    Sulfonyl fluorides are known to inhibit esterases. Early work from our laboratory has identified hexadecyl sulfonylfluoride (AM374) as a potent in vitro and in vivo inhibitor of fatty acid amide hydrolase (FAAH). We now report on later generation sulfonyl fluoride analogs that exhibit potent and selective inhibition of FAAH. Using recombinant rat and human FAAH, we show that 5-(4-hydroxyphenyl)pentanesulfonyl fluoride (AM3506) has similar inhibitory activity for both the rat and the human enzyme, while rapid dilution assays and mass spectrometry analysis suggest that the compound is a covalent modifier for FAAH and inhibits its action in an irreversible manner. Our SAR results are highlighted by molecular docking of key analogs. PMID:23083016

  10. Identification of novel functional inhibitors of acid sphingomyelinase.

    PubMed

    Kornhuber, Johannes; Muehlbacher, Markus; Trapp, Stefan; Pechmann, Stefanie; Friedl, Astrid; Reichel, Martin; Mühle, Christiane; Terfloth, Lothar; Groemer, Teja W; Spitzer, Gudrun M; Liedl, Klaus R; Gulbins, Erich; Tripal, Philipp

    2011-01-01

    We describe a hitherto unknown feature for 27 small drug-like molecules, namely functional inhibition of acid sphingomyelinase (ASM). These entities named FIASMAs (Functional Inhibitors of Acid SphingoMyelinAse), therefore, can be potentially used to treat diseases associated with enhanced activity of ASM, such as Alzheimer's disease, major depression, radiation- and chemotherapy-induced apoptosis and endotoxic shock syndrome. Residual activity of ASM measured in the presence of 10 µM drug concentration shows a bimodal distribution; thus the tested drugs can be classified into two groups with lower and higher inhibitory activity. All FIASMAs share distinct physicochemical properties in showing lipophilic and weakly basic properties. Hierarchical clustering of Tanimoto coefficients revealed that FIASMAs occur among drugs of various chemical scaffolds. Moreover, FIASMAs more frequently violate Lipinski's Rule-of-Five than compounds without effect on ASM. Inhibition of ASM appears to be associated with good permeability across the blood-brain barrier. In the present investigation, we developed a novel structure-property-activity relationship by using a random forest-based binary classification learner. Virtual screening revealed that only six out of 768 (0.78%) compounds of natural products functionally inhibit ASM, whereas this inhibitory activity occurs in 135 out of 2028 (6.66%) drugs licensed for medical use in humans. PMID:21909365

  11. Identification of Novel Functional Inhibitors of Acid Sphingomyelinase

    PubMed Central

    Trapp, Stefan; Pechmann, Stefanie; Friedl, Astrid; Reichel, Martin; Mühle, Christiane; Terfloth, Lothar; Groemer, Teja W.; Spitzer, Gudrun M.; Liedl, Klaus R.; Gulbins, Erich; Tripal, Philipp

    2011-01-01

    We describe a hitherto unknown feature for 27 small drug-like molecules, namely functional inhibition of acid sphingomyelinase (ASM). These entities named FIASMAs (Functional Inhibitors of Acid SphingoMyelinAse), therefore, can be potentially used to treat diseases associated with enhanced activity of ASM, such as Alzheimer's disease, major depression, radiation- and chemotherapy-induced apoptosis and endotoxic shock syndrome. Residual activity of ASM measured in the presence of 10 µM drug concentration shows a bimodal distribution; thus the tested drugs can be classified into two groups with lower and higher inhibitory activity. All FIASMAs share distinct physicochemical properties in showing lipophilic and weakly basic properties. Hierarchical clustering of Tanimoto coefficients revealed that FIASMAs occur among drugs of various chemical scaffolds. Moreover, FIASMAs more frequently violate Lipinski's Rule-of-Five than compounds without effect on ASM. Inhibition of ASM appears to be associated with good permeability across the blood-brain barrier. In the present investigation, we developed a novel structure-property-activity relationship by using a random forest-based binary classification learner. Virtual screening revealed that only six out of 768 (0.78%) compounds of natural products functionally inhibit ASM, whereas this inhibitory activity occurs in 135 out of 2028 (6.66%) drugs licensed for medical use in humans. PMID:21909365

  12. Cyclopentanedi- and tricarboxylic acids as squalene synthase inhibitors: syntheses and evaluation.

    PubMed

    Shen, W; Garvey, D S; Cohen, J; Stein, H; Rosenberg, S H

    1998-04-21

    Based on earlier lead squalene synthase inhibitor A-87049 (3) and zaragozic acids, a series of cyclopentanedi- and tricarboxylic acids were synthesized and evaluated against the enzyme. Some exhibited good potency and SAR revealed the importance of conformation and substitution pattern of these synthetic inhibitors. PMID:9871507

  13. Development and testing of a low toxicity acid corrosion inhibitor for industrial cleaning applications

    SciTech Connect

    Frenier, W.W.

    1997-02-01

    A low toxicity corrosion inhibitor used in hydrochloric acid cleaning formulations has been developed. This formulation does not contain formaldehyde. It contains cinnamaldehyde, quaternary nitrogen salts, and a nonionic surfactant, none of which are currently known or suspected to be carcinogens. In laboratory tests, corrosion protection values were equivalent to those provided by current commercial acid inhibitors. Field tests using the low toxicity inhibitor were conducted.

  14. Multicistronic lentiviral vector-mediated striatal gene transfer of aromatic L-amino acid decarboxylase, tyrosine hydroxylase, and GTP cyclohydrolase I induces sustained transgene expression, dopamine production, and functional improvement in a rat model of Parkinson's disease.

    PubMed

    Azzouz, Mimoun; Martin-Rendon, Enca; Barber, Robert D; Mitrophanous, Kyriacos A; Carter, Emma E; Rohll, Jonathan B; Kingsman, Susan M; Kingsman, Alan J; Mazarakis, Nicholas D

    2002-12-01

    Parkinson's disease (PD) is a neurodegenerative disorder characterized by the selective loss of dopaminergic neurons in the substantia nigra. This loss leads to complete dopamine depletion in the striatum and severe motor impairment. It has been demonstrated previously that a lentiviral vector system based on equine infectious anemia virus (EIAV) gives rise to highly efficient and sustained transduction of neurons in the rat brain. Therefore, a dopamine replacement strategy using EIAV has been investigated as a treatment in the 6-hydroxydopamine (6-OHDA) animal model of PD. A self-inactivating EIAV minimal lentiviral vector that expresses tyrosine hydroxylase (TH), aromatic amino acid dopa decarboxylase (AADC), and GTP cyclohydrolase 1 (CH1) in a single transcription unit has been generated. In cultured striatal neurons transduced with this vector, TH, AADC, and CH1 proteins can all be detected. After stereotactic delivery into the dopamine-denervated striatum of the 6-OHDA-lesioned rat, sustained expression of each enzyme and effective production of catecholamines were detected, resulting in significant reduction of apomorphine-induced motor asymmetry compared with control animals (p < 0.003). Expression of each enzyme in the striatum was observed for up to 5 months after injection. These data indicate that the delivery of three catecholaminergic synthetic enzymes by a single lentiviral vector can achieve functional improvement and thus open the potential for the use of this vector for gene therapy of late-stage PD patients. PMID:12451130

  15. Inhibition of erythromycin synthesis by disruption of malonyl-coenzyme A decarboxylase gene eryM in Saccharopolyspora erythraea.

    PubMed Central

    Hsieh, Y J; Kolattukudy, P E

    1994-01-01

    Malonyl-coenzyme A (malonyl-CoA) decarboxylase is widely distributed in prokaryotes and eukaryotes. However, the biological function of this enzyme has not been established in any organism. To elucidate the structure and function of this enzyme, the malonyl-CoA decarboxylase gene from Saccharopolyspora erythraea (formerly Streptomyces erythreaus) was cloned and sequenced. This gene would encode a polypeptide of 417 amino acids. The deduced amino acid sequence matched the experimentally determined amino acid sequences of 25 N-terminal residues each of the enzyme and of an internal peptide obtained by proteolysis of the purified enzyme. This decarboxylase showed homology with aminoglycoside N6'-acetyltransferases of Pseudomonas aeruginosa, Serratia marcescens, and Klebsiella pneumoniae. Northern (RNA) blot analysis revealed a single transcript. The transcription initiation site was 220 bp upstream of the start codon. When expressed in Escherichia coli, the S. erythraea malonyl-CoA decarboxylase gene yielded a protein that cross-reacted with antiserum prepared against S. erythraea malonyl-CoA decarboxylase and catalyzed decarboxylation of [3-14C]malonyl-CoA to acetyl-CoA and 14CO2. The S. erythraea malonyl-CoA decarboxylase gene was disrupted by homologous recombination using an integrating vector pWHM3. The gene-disrupted transformant did not produce immunologically cross-reacting 45-kDa decarboxylase, lacked malonyl-CoA decarboxylase activity, and could not produce erythromycin. Exogenous propionate restored the ability to produce erythromycin. These results strongly suggest that the decarboxylase provides propionyl-CoA for erythromycin synthesis probably via decarboxylation of methylmalonyl-CoA derived from succinyl-CoA, and therefore the malonyl-CoA decarboxylase gene is designated eryM. The gene disrupted mutants also did not produce pigments. Images PMID:8300527

  16. Molecular analysis of the glutamate decarboxylase locus in Streptococcus thermophilus ST110

    Technology Transfer Automated Retrieval System (TEKTRAN)

    GABA ('-aminobutyric acid) is generated from glutamate by the action of glutamic acid decarboxylase (GAD) and characterized by hypotensive, diuretic and tranquilizing effects in humans and animals. The production of GABA by lactic acid starter bacteria would enhance the functionality of fermented da...

  17. Detection and transfer of the glutamate decarboxylase gene in Streptococcus thermophilus

    Technology Transfer Automated Retrieval System (TEKTRAN)

    GABA (gamma-aminobutyric acid) is generated from glutamate by the action of glutamic acid decarboxylase (GAD) and characterized by hypotensive, diuretic and tranquilizing effects in humans and animals. The production of GABA by lactic acid starter bacteria would enhance the functionality of fermen...

  18. Characterization of arginine decarboxylase from Dianthus caryophyllus.

    PubMed

    Ha, Byung Hak; Cho, Ki Joon; Choi, Yu Jin; Park, Ky Young; Kim, Kyung Hyun

    2004-04-01

    Arginine decarboxylase (ADC, EC 4.1.1.9) is a key enzyme in the biosynthesis of polyamines in higher plants, whereas ornithine decarboxylase represents the sole pathway of polyamine biosynthesis in animals. Previously, we characterized a genomic clone from Dianthus caryophyllus, in which the deduced polypeptide of ADC was 725 amino acids with a molecular mass of 78 kDa. In the present study, the ADC gene was subcloned into the pGEX4T1 expression vector in combination with glutathione S-transferase (GST). The fusion protein GST-ADC was water-soluble and thus was purified by sequential GSTrap-arginine affinity chromatography. A thrombin-mediated on-column cleavage reaction was employed to release free ADC from GST. Hiload superdex gel filtration FPLC was then used to obtain a highly purified ADC. The identity of the ADC was confirmed by immunoblot analysis, and its specific activity with respect to (14)C-arginine decarboxylation reaction was determined to be 0.9 CO(2) pkat mg(-1) protein. K(m) and V(max) of the reaction between ADC and the substrate were 0.077 +/- 0.001 mM and 6.0 +/- 0.6 pkat mg(-1) protein, respectively. ADC activity was reduced by 70% in the presence of 0.1 mM Cu(2+) or CO(2+), but was only marginally affected by Mg(2+), or Ca(2+) at the same concentration. Moreover, spermine at 1 mM significantly reduced its activity by 30%. PMID:15120115

  19. Assessment of CD4+ T Cell Responses to Glutamic Acid Decarboxylase 65 Using DQ8 Tetramers Reveals a Pathogenic Role of GAD65 121–140 and GAD65 250–266 in T1D Development

    PubMed Central

    Chow, I-Ting; Yang, Junbao; Gates, Theresa J.; James, Eddie A.; Mai, Duy T.; Greenbaum, Carla; Kwok, William W.

    2014-01-01

    Susceptibility to type 1 diabetes (T1D) is strongly associated with MHC class II molecules, particularly HLA-DQ8 (DQ8: DQA1*03:01/DQB1*03:02). Monitoring T1D-specific T cell responses to DQ8-restricted epitopes may be key to understanding the immunopathology of the disease. In this study, we examined DQ8-restricted T cell responses to glutamic acid decarboxylase 65 (GAD65) using DQ8 tetramers. We demonstrated that GAD65121–140 and GAD65250–266 elicited responses from DQ8+ subjects. Circulating CD4+ T cells specific for these epitopes were detected significantly more often in T1D patients than in healthy individuals after in vitro expansion. T cell clones specific for GAD65121–140 and GAD65250–266 carried a Th1-dominant phenotype, with some of the GAD65121–140-specific T cell clones producing IL-17. GAD65250–266-specific CD4+ T cells could also be detected by direct ex vivo staining. Analysis of unmanipulated peripheral blood mononuclear cells (PBMCs) revealed that GAD65250–266-specific T cells could be found in both healthy and diabetic individuals but the frequencies of specific T cells were higher in subjects with type 1 diabetes. Taken together, our results suggest a proinflammatory role for T cells specific for DQ8-restricted GAD65121–140 and GAD65250–266 epitopes and implicate their possible contribution to the progression of T1D. PMID:25405480

  20. Glutamatergic or GABAergic neuron-specific, long-term expression in neocortical neurons from helper virus-free HSV-1 vectors containing the phosphate-activated glutaminase, vesicular glutamate transporter-1, or glutamic acid decarboxylase promoter

    PubMed Central

    Rasmussen, Morten; Kong, Lingxin; Zhang, Guo-rong; Liu, Meng; Wang, Xiaodan; Szabo, Gabor; Curthoys, Norman P.; Geller, Alfred I.

    2009-01-01

    Many potential uses of direct gene transfer into neurons require restricting expression to one of the two major types of forebrain neurons, glutamatergic or GABAergic neurons. Thus, it is desirable to develop virus vectors that contain either a glutamatergic or GABAergic neuron-specific promoter. The brain/kidney phosphate-activated glutaminase (PAG), the product of the GLS1 gene, produces the majority of the glutamate for release as neurotransmitter, and is a marker for glutamatergic neurons. A PAG promoter was partially characterized using a cultured kidney cell line. The three vesicular glutamate transporters (VGLUTs) are expressed in distinct populations of neurons, and VGLUT1 is the predominant VGLUT in the neocortex, hippocampus, and cerebellar cortex. Glutamic acid decarboxylase (GAD) produces GABA; the two molecular forms of the enzyme, GAD65 and GAD67, are expressed in distinct, but largely overlapping, groups of neurons, and GAD67 is the predominant form in the neocortex. In transgenic mice, an ∼9 kb fragment of the GAD67 promoter supports expression in most classes of GABAergic neurons. Here, we constructed plasmid (amplicon) Herpes Simplex Virus (HSV-1) vectors that placed the Lac Z gene under the regulation of putative PAG, VGLUT1, or GAD67 promoters. Helper virus-free vector stocks were delivered into postrhinal cortex, and the rats were sacrificed 4 days or 2 months later. The PAG or VGLUT1 promoters supported ∼90 % glutamatergic neuron-specific expression. The GAD67 promoter supported ∼90 % GABAergic neuron-specific expression. Long-term expression was observed using each promoter. Principles for obtaining long-term expression from HSV-1 vectors, based on these and other results, are discussed. Long-term glutamatergic or GABAergic neuron-specific expression may benefit specific experiments on learning or specific gene therapy approaches. Of note, promoter analyses might identify regulatory elements that determine a glutamatergic or GABAergic

  1. Purification, characterization, and complete amino acid sequence of a trypsin inhibitor from amaranth (Amaranthus hypochondriacus) seeds.

    PubMed Central

    Valdes-Rodriguez, S; Segura-Nieto, M; Chagolla-Lopez, A; Verver y Vargas-Cortina, A; Martinez-Gallardo, N; Blanco-Labra, A

    1993-01-01

    A protein proteinase inhibitor was purified from a seed extract of amaranth (Amaranthus hypochondriacus) by precipitation with (NH4)2SO4, gel-filtration chromatography, ion-exchange chromatography, and reverse-phase high-performance liquid chromatography. It is a 69-amino acid protein with a high content of valine, arginine, and glutamic acid, but lacking in methionine. The inhibitor has a relative molecular weight of 7400 and an isoelectric point of 7.5. It is a serine proteinase inhibitor that recognizes chymotrypsin, trypsin, and trypsin-like proteinase activities extracted from larvae of the insect Prostephanus truncatus. This inhibitor belongs to the potato-I inhibitor family, showing the closest homology (59.5%) with the Lycopersicum peruvianum trypsin inhibitor, and (51%) with the proteinase inhibitor 5 extracted from the seeds of Cucurbita maxima. The position of the lysine-aspartic acid residues present in the active site of the amaranth inhibitor are found in almost the same relative position as in the inhibitor from C. maxima. PMID:8290633

  2. Cloning and sequencing of pyruvate decarboxylase (PDC) genes from bacteria and uses therefor

    DOEpatents

    Maupin-Furlow, Julie A [Gainesville, FL; Talarico, Lee Ann [Gainesville, FL; Raj, Krishnan Chandra [Tamil Nadu, IN; Ingram, Lonnie O [Gainesville, FL

    2008-02-05

    The invention provides isolated nucleic acids molecules which encode pyruvate decarboxylase enzymes having improved decarboxylase activity, substrate affinity, thermostability, and activity at different pH. The nucleic acids of the invention also have a codon usage which allows for high expression in a variety of host cells. Accordingly, the invention provides recombinant expression vectors containing such nucleic acid molecules, recombinant host cells comprising the expression vectors, host cells further comprising other ethanologenic enzymes, and methods for producing useful substances, e.g., acetaldehyde and ethanol, using such host cells.

  3. Amidation inhibitors 4-phenyl-3-butenoic acid and 5-(acetylamino)-4-oxo-6-phenyl-2-hexenoic acid methyl ester are novel HDAC inhibitors with anti-tumorigenic properties.

    PubMed

    Ali, Amna; Burns, Timothy J; Lucrezi, Jacob D; May, Sheldon W; Green, George R; Matesic, Diane F

    2015-08-01

    4-Phenyl-3-butenoic acid (PBA) is an inhibitor of peptidylglycine alpha-amidating monooxygenase with anti-inflammatory properties that has been shown to inhibit the growth of ras-mutated epithelial and human lung carcinoma cells. In this report, we show that PBA also increases the acetylation levels of selected histone subtypes in a dose and time dependent manner, an effect that is attributable to the inhibition of histone deacetylase (HDAC) enzymes. Comparison studies with the known HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) using high resolution two-dimensional polyacrylamide gels and Western analysis provide evidence that PBA acts as an HDAC inhibitor within cells. PBA and a more potent amidation inhibitor, 5-(acetylamino)-4-oxo-6-phenyl-2-hexenoic acid methyl ester (AOPHA-Me), inhibit HDAC enzymes in vitro at micromolar concentrations, with IC50 values approximately 30 fold lower for AOPHA-Me than PBA for selected HDAC isoforms. Overall, these results indicate that PBA and AOPHA-Me are novel anti-tumorigenic HDAC inhibitors. PMID:26065689

  4. Peptides inhibitors of acid-sensing ion channels.

    PubMed

    Diochot, S; Salinas, M; Baron, A; Escoubas, P; Lazdunski, M

    2007-02-01

    Acid-sensing ion channels (ASICs) channels are proton-gated cationic channels mainly expressed in central and peripheric nervous system and related to the epithelial amiloride-sensitive Na(+) channels and to the degenerin family of ion channels. ASICs comprise four proteins forming functional channel subunits (ASIC1a, ASIC1b, ASIC2a, and ASIC3) and two proteins (ASIC2b and ASIC4) without yet known activators. Functional channels are activated by external pH variations ranging from pH(0.5) 6.8 to 4.0 and currents are characterized by either rapid kinetics of inactivation (ASIC1a, ASIC1b, ASIC3) or slow kinetics of inactivation (ASIC2a) and sometimes the presence of a plateau phase (ASIC3). ASIC1a and ASIC3, which are expressed in nociceptive neurons, have been implicated in inflammation and knockout mice studies support the role of ASIC3 in various pain processes. ASIC1a seems more related to synaptic plasticity, memory, learning and fear conditioning in the CNS. ASIC2a contributes to hearing in the cochlea, sour taste sensation, and visual transduction in the retina. The pharmacology of ASICs is limited to rather nonselective drugs such as amiloride, nonsteroid anti-inflammatory drugs, and neuropeptides. Recently, two peptides, PcTx1 and APETx2, isolated from a spider and a sea anemone, have been characterized as selective and high-affinity inhibitors for ASIC1a and ASIC3 channels, respectively. PcTx1 inhibits ASIC1a homomers with an affinity of 0.7 nM (IC(50)) without any effect on ASIC1a containing heteromers and thus helped to characterize ASIC1a homomeric channels in peripheric and central neurons. PcTx1 acts as a gating modifier since it shifts the channel from the resting to an inactivated state by increasing its affinity for H(+). APETx2 is less selective since it inhibits several ASIC3-containing channels (IC(50) from 63 nM to 2 microM) and to date its mode of action is unknown. Nevertheless, APETx2 structure is related to other sea anemone peptides, which

  5. [Effect of proteolysis inhibitors on the incorporation of labelled amino acids into proteins].

    PubMed

    Konikova, A S; Korotkina, R N

    1975-01-01

    Role of peptide bond breaks in the incorporation of amino acids into proteins in a "protein--amino acid" system is investigated. For this purpose the incorporation of labelled amino acids into trypsin under the inhibition of its autolysis by a specific inhibitor from soybean and epsilon-amino-caproic acid is studied. The trypsin inhibitor from soybean is found to suppress considerably the incorporation of 14C-glycine, 14C-lysine and 14C-methionine into crystal trypsin and not to affect the incorporation of labelled amino acids into chomotrypsin, papain and carboxypeptidase. Epsilon-Aminocaproic acid inhibited 14C-glycine incorporation into crystal trypsin by 40% and did not change its incorporation level into serum albumin. The dependency of amino acid incorporation level into trypsin on the activity of autolysis in the "protein--amino acid" system is demonstrated. PMID:1212456

  6. Comparative acid tolerances and inhibitor sensitivities of isolated F-ATPases of oral lactic acid bacteria.

    PubMed Central

    Sturr, M G; Marquis, R E

    1992-01-01

    pH activity profiles and inhibitor sensitivities were compared for membrane ATPases isolated from three oral lactic acid bacteria, Lactobacillus casei ATCC 4646, Streptococcus mutans GS-5, and Streptococcus sanguis NCTC 10904, with, respectively, high, moderate, and low levels of acid tolerance. Membranes containing F1F0 ATPases were isolated by means of salt lysis of cells treated with muralytic enzymes. Membrane-free F1F0 complexes were then isolated from membranes by detergent extraction with Triton X-100 or octylglucoside. Finally, F1 complexes free of the proton-conducting F0 sector were obtained by washing membranes with buffers of low ionic strength. The pH activity profiles of the membrane-associated enzymes reflected the general acid tolerances of the organisms from which they were isolated; for example, pH optima were approximately 5.5, 6.0, and 7.0, respectively, for enzymes from L. casei, S. mutans, and S. sanguis. Roughly similar profiles were found for membrane-free F1F0 complexes, which were stabilized by phospholipids against loss of activity during storage. However, profiles for F1 enzymes were distinctly narrower, indicating that association with F0 and possibly other membrane components enhanced tolerance to both acid and alkaline media. All of the enzymes were found to have similar sensitivities to Al-F complexes, but only F1F0 enzymes were highly sensitive to dicyclohexylcarbodiimide. The procedures described for isolation of membrane-free F1F0 forms of the enzymes from oral lactic acid bacteria will be of use in future studies of the characteristics of the enzymes, especially in studies with liposomes. PMID:1386211

  7. A new case of malonyl-CoA decarboxylase deficiency with mild clinical features.

    PubMed

    Liu, Huan; Tan, Dongqiong; Han, Lianshu; Ye, Jun; Qiu, Wenjuan; Gu, Xuefan; Zhang, Huiwen

    2016-05-01

    Malonyl-CoA decarboxylase deficiency is an extremely rare autosomal recessive inborn error of fatty acid metabolism. It usually follows a severe disease course and presents poor prognosis without treatment. Here, we report an affected female juvenile with a mild clinical and biochemical phenotype who mainly featured poor schooling without cardiomyopathy and metabolic acidosis. She was suspected of malonyl-CoA decarboxylase deficiency due to a 57-kb deletion in 16q23.3 encompassing the MLCYD gene revealed by chromosome microarray. Malonyl-CoA decarboxylase deficiency was then confirmed by acylcarnitine analysis and organic acid analysis. Real-time PCR analysis of the patient revealed the first three exon deletion of the MLYCD gene, which was maternally inherited. DNA sequencing of the MLYCD gene of the patient identified a novel heterozygous mutation (c.911G>A, p.G304E) in exon 4 that was paternally inherited. The patient urine malonic acid dissolved and had a better school record in 6 month after initiation of fat-limited diet. At 1 year post treatment, the blood malonylcarnitine level decreased remarkably. Our result expands the phenotype of malonyl-CoA decarboxylase deficiency and suggests attentions should be paid to the mild form of disorders, for example, malonyl-CoA decarboxylase deficiency, which usually present a severe disease course. © 2016 Wiley Periodicals, Inc. PMID:26858006

  8. 2-Aminoimidazole Amino Acids as Inhibitors of the Binuclear Manganese Metalloenzyme Human Arginase I

    SciTech Connect

    Ilies, M.; Di Costanzo, L; North, M; Scott, J; Christianson, D

    2010-01-01

    Arginase, a key metalloenzyme of the urea cycle that converts L-arginine into L-ornithine and urea, is presently considered a pharmaceutical target for the management of diseases associated with aberrant L-arginine homeostasis, such as asthma, cardiovascular diseases, and erectile dysfunction. We now report the design, synthesis, and evaluation of a series of 2-aminoimidazole amino acid inhibitors in which the 2-aminoimidazole moiety serves as a guanidine mimetic. These compounds represent a new class of arginase inhibitors. The most potent inhibitor identified in this study, 2-(S)-amino-5-(2-aminoimidazol-1-yl)pentanoic acid (A1P, 10), binds to human arginase I with K{sub d} = 2 {micro}M and significantly attenuates airways hyperresponsiveness in a murine model of allergic airways inflammation. These findings suggest that 2-aminoimidazole amino acids represent new leads for the development of arginase inhibitors with promising pharmacological profiles.

  9. 2-Aminoimidazole Amino Acids as Inhibitors of the Binuclear Manganese Metalloenzyme Human Arginase I

    PubMed Central

    Ilies, Monica; Di Costanzo, Luigi; North, Michelle L.; Scott, Jeremy A.; Christianson, David W.

    2010-01-01

    Arginase, a key metalloenzyme of the urea cycle that converts L-arginine into L-ornithine and urea, is presently considered a pharmaceutical target for the management of diseases associated with aberrant L-arginine homeostasis, such as asthma, cardiovascular diseases, and erectile dysfunction. We now report the design, synthesis, and evaluation of a series of 2-aminoimidazole amino acids inhibitors in which the 2-aminoimidazole moiety serves as a guanidine mimetic. These compounds represent a new class of arginase inhibitors. The most potent inhibitor identified in this study, 2-(S)-amino-5-(2-aminoimidazol-1-yl)-pentanoic acid (A1P, 10), binds to human arginase I with Kd = 2 μM and significantly attenuates airways hyperresponsiveness in a murine model of allergic airways inflammation. These findings suggest that 2-aminoimidazole amino acids represent new leads for the development of arginase inhibitors with promising pharmacological profiles. PMID:20441173

  10. Inhibitors of Fatty Acid Amide Hydrolase and Monoacylglycerol Lipase: New Targets for Future Antidepressants.

    PubMed

    Ogawa, Shintaro; Kunugi, Hiroshi

    2015-01-01

    Cannabis and analogs of Δ9-tetrahydrocannabinol have been used for therapeutic purposes, but their therapeutic use remains limited because of various adverse effects. Endogenous cannabinoids have been discovered, and dysregulation of endocannabinoid signaling is implicated in the pathophysiology of major depressive disorder (MDD). Recently, endocannabinoid hydrolytic enzymes such as fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) have become new therapeutic targets in the treatment of MDD. Several FAAH or MAGL inhibitors are reported to have no cannabimimetic side effects and, therefore, are new potential therapeutic options for patients with MDD who are resistant to first-line antidepressants (selective serotonin and serotonin-norepinephrine reuptake inhibitors). In this review, we focus on the possible relationships between MDD and the endocannabinoid system as well as the inhibitors' therapeutic potential. MAGL inhibitors may reduce inflammatory responses through activation of cannabinoid receptor type 2. In the hypothalamic-pituitary-adrenal axis, repeated FAAH inhibitor administration may be beneficial for reducing circulating glucocorticoid levels. Both FAAH and MAGL inhibitors may contribute to dopaminergic system regulation. Recently, several new inhibitors have been developed with strong potency and selectivity. FAAH inhibitor, MAGL inhibitor, or dual blocker use would be promising new treatments for MDD. Further pre-clinical studies and clinical trials using these inhibitors are warranted. PMID:26630956

  11. Volatile and biogenic amines, microbiological counts, and bacterial amino acid decarboxylase activity throughout the salt-ripening process of anchovies (Engraulis encrasicholus).

    PubMed

    Pons-Sánchez-Cascado, S; Veciana-Nogués, M T; Bover-Cid, S; Mariné-Font, A; Vidal-Carou, M C

    2005-08-01

    Chemical and microbiological parameters were studied during the industrial production of salt-ripened anchovies (Engraulis encrasicholus). Gradual acidification and increases in the proteolysis index and in total volatile basic nitrogen were observed. At the end of the maturing process, the values reached pH 5.55 +/- 0.03, 21.33 +/- 5.82%, and 44.06 +/- 12.47 mg/ 100 g, respectively. In the three studied anchovy batches, the biogenic amines tyramine, histamine, putrescine, cadaverine, and agmatine increased during ripening. The highest values were found in the batch where initial microbial load was highest (batch 1), especially for enterobacteria and enterococci. Tyramine was the most abundant amine, reaching values from nondetectable to 90 mg/kg, whereas histamine did not surpass 20 mg/kg. Among the microorganisms isolated, Enterobacter cloacae, Aerococcus viridans, Kocuria varians, and Staphylococcus chromogenes were able to decarboxylate amino acids and produce biogenic amines in vitro. Most (70.59%) of the microorganisms identified were able to produce histamine, 23.53% were able to produce the diamines putrescine and cadaverine, and only 11.76% were able to produce tyramine, although this substance was the major biogenic amine found in anchovy samples. PMID:21132979

  12. Overexpression of Tyrosine hydroxylase and Dopa decarboxylase associated with pupal melanization in Spodoptera exigua

    PubMed Central

    Liu, Sisi; Wang, Mo; Li, Xianchun

    2015-01-01

    Melanism has been found in a wide range of species, but the molecular mechanisms involved remain largely elusive. In this study, we studied the molecular mechanisms of the pupal melanism in Spodoptera exigua. The full length cDNA sequences of tyrosine hydroxylase (TH) and dopa decarboxylase (DDC), two key enzymes in the biosynthesis pathway of melanin, were cloned, and their temporal expression patterns in the integument were compared during the larval-pupal metamorphosis process of the S. exigua wild type (SEW) and melanic mutant (SEM) strains. No amino acid change in the protein sequence of TH and DDC was found between the two strains. Both DDC and TH were significantly over-expressed in the integument of the SEM strain at late-prepupa and 0 h pupa, respectively, compared with those of the SEW strain. Feeding 5th instar larvae of SEM with diets incorporated with 1 mg/g of the DDC inhibitor L-α-Methyl-DOPA and 0.75 mg/g of the TH inhibitor 3-iodo-tyrosine (3-IT) resulted in 20% pupae with partially-rescued phenotype and 68.2% of pupae with partially- or fully-rescued phenotype, respectively. These results indicate that overexpressions of TH and DDC are involved in the pupal melanization of S. exigua. PMID:26084938

  13. Overexpression of Tyrosine hydroxylase and Dopa decarboxylase associated with pupal melanization in Spodoptera exigua.

    PubMed

    Liu, Sisi; Wang, Mo; Li, Xianchun

    2015-01-01

    Melanism has been found in a wide range of species, but the molecular mechanisms involved remain largely elusive. In this study, we studied the molecular mechanisms of the pupal melanism in Spodoptera exigua. The full length cDNA sequences of tyrosine hydroxylase (TH) and dopa decarboxylase (DDC), two key enzymes in the biosynthesis pathway of melanin, were cloned, and their temporal expression patterns in the integument were compared during the larval-pupal metamorphosis process of the S. exigua wild type (SEW) and melanic mutant (SEM) strains. No amino acid change in the protein sequence of TH and DDC was found between the two strains. Both DDC and TH were significantly over-expressed in the integument of the SEM strain at late-prepupa and 0 h pupa, respectively, compared with those of the SEW strain. Feeding 5(th) instar larvae of SEM with diets incorporated with 1 mg/g of the DDC inhibitor L-α-Methyl-DOPA and 0.75 mg/g of the TH inhibitor 3-iodo-tyrosine (3-IT) resulted in 20% pupae with partially-rescued phenotype and 68.2% of pupae with partially- or fully-rescued phenotype, respectively. These results indicate that overexpressions of TH and DDC are involved in the pupal melanization of S. exigua. PMID:26084938

  14. Purification of acetoacetate decarboxylase from Clostridium acetobutylicum ATCC 824 and cloning of the acetoacetate decarboxylase gene in Escherichia coli

    SciTech Connect

    Petersen, D.J.; Bennett, G.N. )

    1990-11-01

    In Clostridium acetobutylicum ATCC 824, acetoacetate decarboxylase (EC 4.1.1.4) is essential for solvent production, catalyzing the decarboxylation of acetoacetate to acetone. We report here the purification of the enzyme from C. acetobutylicum ATCC 824 and the cloning and expression of the gene encoding the acetoacetate decarboxylase enzyme in Escherichia coli. A bacteriophage lambda EMBL3 library of C. acetobutylicum DNA was screened by plaque hybridization, using oligodeoxynucleotide probes derived from the N-terminal amino acid sequence obtained from the purified protein. Phage DNA from positive plaques was analyzed by Southern hybridization. Restriction mapping and subsequent subcloning of DNA fragments hybridizing to the probes localized the gene within an {approximately}2.1-kb EcoRI/BglII fragment. A polypeptide with a molecular weight of {approximately}28,000 corresponding to that of the purified acetoacetate decarboxylase was observed in both Western blots (immunoblots) and maxicell analysis of whole-cell extracts of E. coli harboring the clostridial gene. Although the expression of the gene is tightly regulated in C. acetobutylicum, it was well expressed in E. coli, although from a promoter sequence of clostridial origin.

  15. A New alpha-Glucosidase Inhibitor, 10-Hydroxy-8(E)-Octadecenoic Acid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In our continuous effort to screen natural products for their anti-microbial and enzyme inhibitor activities, we found that 10-Hydroxy-8(E)-Octadecenoic acid (HOD) exhibited strong anti- a-glucosidase (EC 3.2.1.20) activity. HOD is an intermediate in the bioconversion of oleic acid to 7,10-dihydrox...

  16. [The clinical evaluation of the hypocholesterolemic effects of an inhibitor of cholesterol synthesis: mevalonic acid].

    PubMed

    Del Nero, E; Aloe, N; Augeri, C; Avola, F; Carta, G; Cavagnaro, A; De Grandi, R; Gianfreda, M; Magro, G P; Mazzarello, G P

    1992-07-01

    Twenty eight patients with heterozygous familial hypercholesterolemia were treated with mevalonic acid (an inhibitor of cholesterol synthesis) for 45 days. Patients received a daily dose of 750 to 1500 mg mevalonic acid depending on plasma cholesterol levels. Results showed a significant reduction in cholesterol values whereas no significant difference was observed in HDL cholesterol and triglyceride levels. PMID:1505176

  17. COMPARATIVE PATHOGENESIS OF HALOACETIC ACID AND PROTEIN KINASE INHIBITOR EMBRYOTOXICITY IN MOUSE WHOLE EMBRYO CULTURE

    EPA Science Inventory

    Comparative pathogenesis of haloacetic acid and protein kinase inhibitor embryotoxicity in mouse whole embryo culture.

    Ward KW, Rogers EH, Hunter ES 3rd.

    Curriculum in Toxicology, University of North Carolina at Chapel Hill, 27599-7270, USA.

    Haloacetic acids ...

  18. The Use of Ascorbate as an Oxidation Inhibitor in Prebiotic Amino Acid Synthesis: A Cautionary Note

    NASA Astrophysics Data System (ADS)

    Kuwahara, Hideharu; Eto, Midori; Kawamoto, Yukinori; Kurihara, Hironari; Kaneko, Takeo; Obayashi, Yumiko; Kobayashi, Kensei

    2012-12-01

    It is generally thought that the terrestrial atmosphere at the time of the origin of life was CO2-rich and that organic compounds such as amino acids would not have been efficiently formed abiotically under such conditions. It has been pointed out, however, that the previously reported low yields of amino acids may have been partially due to oxidation by nitrite/nitrate during acid hydrolysis. Specifically, the yield of amino acids was found to have increased significantly (by a factor of several hundred) after acid hydrolysis with ascorbic acid as an oxidation inhibitor. However, it has not been shown that CO2 was the carbon source for the formation of the amino acids detected after acid hydrolysis with ascorbic acid. We therefore reinvestigated the prebiotic synthesis of amino acids in a CO2-rich atmosphere using an isotope labeling experiment. Herein, we report that ascorbic acid does not behave as an appropriate oxidation inhibitor, because it contributes amino acid contaminants as a consequence of its reactions with the nitrogen containing species and formic acid produced during the spark discharge experiment. Thus, amino acids are not efficiently formed from a CO2-rich atmosphere under the conditions studied.

  19. Snake venoms. The amino-acid sequence of trypsin inhibitor E of Dendroaspis polylepis polylepis (Black Mamba) venom.

    PubMed

    Joubert, F J; Strydom, D J

    1978-06-01

    Trypsin inhibitor E from black mamba venom comprises 59 amino acid residues in a single polypeptide chain, cross-linked by three intrachain disulphide bridges. The complete primary structure of inhibitor E was elucidated. The sequence is homologous with trypsin inhibitors from different sources. Unique among this homologous series of proteinase inhibitors, inhibitor E has an affinity for transition metal ions, exemplified here by Cu2 and Co2+. PMID:668688

  20. Glutamic Acid Decarboxylase 65 and Islet Cell Antigen 512/IA-2 Autoantibodies in Relation to Human Leukocyte Antigen Class II DR and DQ Alleles and Haplotypes in Type 1 Diabetes Mellitus ▿

    PubMed Central

    Stayoussef, Mouna; Benmansour, Jihen; Al-Jenaidi, Fayza A.; Said, Hichem B.; Rayana, Chiheb B.; Mahjoub, Touhami; Almawi, Wassim Y.

    2011-01-01

    The frequencies of autoantibodies against glutamic acid decarboxylase 65 (GAD65) and islet cell antigen (ICA) 512/IA-2 (512/IA-2) are functions of the specific human leukocyte antigen (HLA) in type 1 diabetes mellitus (T1D). We investigated the association of HLA class II (DR and DQ) alleles and haplotypes with the presence of GAD and IA-2 autoantibodies in T1D. Autoantibodies were tested in 88 Tunisian T1D patients and 112 age- and gender-matched normoglycemic control subjects by enzyme immunoassay. Among T1D patients, mean anti-GAD antibody titers were higher in the DRB1*030101 allele (P < 0.001), together with the DRB1*030101/DQB1*0201 (P < 0.001) and DRB1*040101/DQB1*0302 (P = 0.002) haplotypes, while lower anti-GAD titers were associated with the DRB1*070101 (P = 0.001) and DRB1*110101 (P < 0.001) alleles and DRB1*070101/DQB1*0201 (P = 0.001) and DRB1*110101/DQB1*030101 (P = 0.001) haplotypes. Mean anti-IA-2 antibody titers were higher in the DRB1*040101 allele (P = 0.007) and DRB1*040101/DQB1*0302 (P = 0.001) haplotypes but were lower in the DRB1*110101 allele (P = 0.010) and the DRB1*110101 (P < 0.001) and DRB1*110101/DQB1*030101 (P = 0.025) haplotypes. Multinomial regression analysis confirmed the positive association of DRB1*030101 and the negative association of DRB1*110101 and DQB1*030101, along with the DRB1*070101/DQB1*0201 and DRB1*110101/DQB1*030101 haplotypes, with anti-GAD levels. In contrast, only the DRB1*040101/DQB1*0302 haplotype was positively associated with altered anti-IA-2 titers. Increased GAD65 and IA-2 antibody positivity is differentially associated with select HLA class II alleles and haplotypes, confirming the heterogeneous nature of T1D. PMID:21490167

  1. Glutamic acid decarboxylase 65 and islet cell antigen 512/IA-2 autoantibodies in relation to human leukocyte antigen class II DR and DQ alleles and haplotypes in type 1 diabetes mellitus.

    PubMed

    Stayoussef, Mouna; Benmansour, Jihen; Al-Jenaidi, Fayza A; Said, Hichem B; Rayana, Chiheb B; Mahjoub, Touhami; Almawi, Wassim Y

    2011-06-01

    The frequencies of autoantibodies against glutamic acid decarboxylase 65 (GAD65) and islet cell antigen (ICA) 512/IA-2 (512/IA-2) are functions of the specific human leukocyte antigen (HLA) in type 1 diabetes mellitus (T1D). We investigated the association of HLA class II (DR and DQ) alleles and haplotypes with the presence of GAD and IA-2 autoantibodies in T1D. Autoantibodies were tested in 88 Tunisian T1D patients and 112 age- and gender-matched normoglycemic control subjects by enzyme immunoassay. Among T1D patients, mean anti-GAD antibody titers were higher in the DRB1*030101 allele (P < 0.001), together with the DRB1*030101/DQB1*0201 (P < 0.001) and DRB1*040101/DQB1*0302 (P = 0.002) haplotypes, while lower anti-GAD titers were associated with the DRB1*070101 (P = 0.001) and DRB1*110101 (P < 0.001) alleles and DRB1*070101/DQB1*0201 (P = 0.001) and DRB1*110101/DQB1*030101 (P = 0.001) haplotypes. Mean anti-IA-2 antibody titers were higher in the DRB1*040101 allele (P = 0.007) and DRB1*040101/DQB1*0302 (P = 0.001) haplotypes but were lower in the DRB1*110101 allele (P = 0.010) and the DRB1*110101 (P < 0.001) and DRB1*110101/DQB1*030101 (P = 0.025) haplotypes. Multinomial regression analysis confirmed the positive association of DRB1*030101 and the negative association of DRB1*110101 and DQB1*030101, along with the DRB1*070101/DQB1*0201 and DRB1*110101/DQB1*030101 haplotypes, with anti-GAD levels. In contrast, only the DRB1*040101/DQB1*0302 haplotype was positively associated with altered anti-IA-2 titers. Increased GAD65 and IA-2 antibody positivity is differentially associated with select HLA class II alleles and haplotypes, confirming the heterogeneous nature of T1D. PMID:21490167

  2. Vesicular monoamine transporter-2 and aromatic L-amino acid decarboxylase gene therapy prevents development of motor complications in parkinsonian rats after chronic intermittent L-3,4-dihydroxyphenylalanine administration.

    PubMed

    Lee, Won Yong; Lee, Eun Ah; Jeon, Mi Young; Kang, Ho Young; Park, Yong Gu

    2006-01-01

    Motor complications after chronic L-3,4-dihydroxyphenylalanine (L-DOPA) therapy occur partly because of the sensitization to dopaminergic agents resulting from pulsatile dopaminergic stimulation. The loss of presynaptic storage contributes to short duration of action by dopamine. Vesicular monoamine transporter-2 (VMAT-2) controls intraneuronal dopamine storage by packaging dopamine into synaptic vesicles, thereby allowing exocytotic release of dopamine. Using primary fibroblast doubly transduced with VMAT-2 and aromatic L-amino acid decarboxylase (AADC) genes, we previously demonstrated the beneficial effects of such double gene transduction in the production, storage, and gradual release of dopamine in vitro and in vivo. In this study, we further evaluate the effect of achieving sustained level of dopamine within the striata by VMAT-2 gene on behavioral response of parkinsonian rats after chronic intermittent L-DOPA administration. Primary fibroblast (PF) cells were genetically modified with AADC and VMAT-2 genes. We grafted primary fibroblast cells, PF with AADC (PFAADC), or doubly transduced PF with AADC and VMAT-2 (PFVMAA) (n = 6 for each group) into parkinsonian rat striata and administered L-DOPA (25 mg/kg/day) intermittently for 4 weeks. For behavioral study, we employed a model of akinesia using forepaw adjusting steps (FAS) that have been well characterized to reflect the effect of the lesion and the antiparkinsonian effect of dopaminergic drugs and transplants. The duration of FAS response to L-DOPA was sustained for a longer duration in rats grafted with PFVMAA cells than in those grafted with either control cells or cells with AADC alone. In PFVMAA-grafted animals, prolonged duration of FAS responses to L-DOPA was sustained even 6 weeks after discontinuation of 4-week intermittent L-DOPA treatment. These findings suggest that the restoration of dopamine storage capacity could enhance the efficacy of L-DOPA therapy and attenuate the motor fluctuations

  3. STEREOLOGICAL ESTIMATES OF THE BASAL FOREBRAIN CELL POPULATION IN THE RAT, INCLUDING NEURONS CONTAINING CHOLINE ACETYLTRANSFERASE (ChAT), GLUTAMIC ACID DECARBOXYLASE (GAD) OR PHOSPHATE-ACTIVATED GLUTAMINASE (PAG) AND COLOCALIZING VESICULAR GLUTAMATE TRANSPORTERS (VGluTs)

    PubMed Central

    GRITTI, I.; HENNY, P.; GALLONI, F.; MAINVILLE, L.; MARIOTTI, M.; JONES, B. E.

    2006-01-01

    The basal forebrain (BF) plays an important role in modulating cortical activity and influencing attention, learning and memory. These activities are fulfilled importantly yet not entirely by cholinergic neurons. Noncholinergic neurons also contribute and are comprised by GABAergic neurons and other possibly glutamatergic neurons. The aim of the present study was to estimate the total number of cells in the BF of the rat and the proportions of that total represented by cholinergic, GABAergic and glutamatergic neurons. For this purpose, cells were counted using unbiased stereological methods within the medial septum, diagonal band, magnocellular preoptic nucleus, substantia innominata and globus pallidus in sections stained for Nissl substance and/or the neurotransmitter enzymes, choline acetyltransferase (ChAT), glutamic acid decarboxylase (GAD) or phosphate-activated glutaminase (PAG). In Nissl-stained sections, the total number of neurons in the BF was estimated as ~355,000 and the numbers of ChAT-immuno-positive (+) as ~22,000, GAD+ ~119,000 and PAG+ ~316,000, corresponding to ~5%, ~35% and ~90% of the total. Thus, of the large population of BF neurons, only a small proportion has the capacity to synthesize acetylcholine (ACh), one third to synthesize GABA and the vast majority to synthesize glutamate (Glu). Moreover, through the presence of PAG, a proportion of ACh- and GABA-synthesizing neurons also have the capacity to synthesize Glu. In sections dual fluorescent immunostained for vesicular transporters, VGluT3 and not VGluT2 was present in the cell bodies of most PAG+ and ChAT+ and half the GAD+ cells. Given previous results showing that VGluT2 and not VGluT3 was present in BF axon terminals and not colocalized with VAChT or VGAT, we conclude that the BF cell population influences cortical and subcortical regions through neurons which release ACh, GABA or Glu from their terminals but which in part can also synthesize and release Glu from their soma or

  4. Inhibitors of Fatty Acid Amide Hydrolase and Monoacylglycerol Lipase: New Targets for Future Antidepressants

    PubMed Central

    Ogawa, Shintaro; Kunugi, Hiroshi

    2015-01-01

    Cannabis and analogs of Δ9-tetrahydrocannabinol have been used for therapeutic purposes, but their therapeutic use remains limited because of various adverse effects. Endogenous cannabinoids have been discovered, and dysregulation of endocannabinoid signaling is implicated in the pathophysiology of major depressive disorder (MDD). Recently, endocannabinoid hydrolytic enzymes such as fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL) have become new therapeutic targets in the treatment of MDD. Several FAAH or MAGL inhibitors are reported to have no cannabimimetic side effects and, therefore, are new potential therapeutic options for patients with MDD who are resistant to first-line antidepressants (selective serotonin and serotonin-norepinephrine reuptake inhibitors). In this review, we focus on the possible relationships between MDD and the endocannabinoid system as well as the inhibitors’ therapeutic potential. MAGL inhibitors may reduce inflammatory responses through activation of cannabinoid receptor type 2. In the hypothalamic–pituitary–adrenal axis, repeated FAAH inhibitor administration may be beneficial for reducing circulating glucocorticoid levels. Both FAAH and MAGL inhibitors may contribute to dopaminergic system regulation. Recently, several new inhibitors have been developed with strong potency and selectivity. FAAH inhibitor, MAGL inhibitor, or dual blocker use would be promising new treatments for MDD. Further pre-clinical studies and clinical trials using these inhibitors are warranted. PMID:26630956

  5. Chitosan as a green inhibitor for copper corrosion in acidic medium.

    PubMed

    El-Haddad, Mahmoud N

    2013-04-01

    The behavior of copper in 0.5 M HCl acid containing different concentrations of chitosan has been studied by weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS) and electrochemical frequency modulation (EFM) measurements. Potentiodynamic polarization measurements show that the chitosan acts essentially as a mixed-type inhibitor. EFM can be used as a rapid and non destructive technique for corrosion rate measurements without prior knowledge of Tafel constants. The results of EIS indicate that the value of CPEs tends to decrease and both charge transfer resistance and inhibition efficiency tend to increase by increasing the inhibitor concentration. The investigated inhibitor has shown good inhibition efficiency in 0.5 M HCl. The adsorption of inhibitor on the copper surface obeys Langmuir's isotherm. Metal surface characterization was performed using scanning electron microscope (SEM) and Fourier transform infrared spectroscopy (FT-IR). Also, the relationship between quantum chemical calculations and experimental inhibition efficiency of the inhibitor was discussed. PMID:23298849

  6. Synthesis of potent inhibitors of anthrax toxin based on poly-L-glutamic acid.

    PubMed

    Joshi, Amit; Saraph, Arundhati; Poon, Vincent; Mogridge, Jeremy; Kane, Ravi S

    2006-01-01

    We report the synthesis of biodegradable polyvalent inhibitors of anthrax toxin based on poly-L-glutamic acid (PLGA). These biocompatible polyvalent inhibitors are at least 4 orders of magnitude more potent than the corresponding monovalent peptides in vitro and are comparable in potency to polyacrylamide-based inhibitors of anthrax toxin assembly. We have elucidated the influence of peptide density on inhibitory potency and demonstrated that these inhibitory potencies are limited by kinetics, with even higher activities seen when the inhibitors are preincubated with the heptameric receptor-binding subunit of anthrax toxin prior to exposure to cells. These polyvalent inhibitors are also effective at neutralizing anthrax toxin in vivo and represent attractive leads for designing biocompatible anthrax therapeutics. PMID:16984137

  7. Pyrazole phenylcyclohexylcarbamates as inhibitors of human fatty acid amide hydrolases (FAAH).

    PubMed

    Aghazadeh Tabrizi, Mojgan; Baraldi, Pier Giovanni; Ruggiero, Emanuela; Saponaro, Giulia; Baraldi, Stefania; Romagnoli, Romeo; Martinelli, Adriano; Tuccinardi, Tiziano

    2015-06-01

    Fatty acid amide hydrolase (FAAH) inhibitors have gained attention as potential therapeutic targets in the management of neuropathic pain. Here, we report a series of pyrazole phenylcyclohexylcarbamate derivatives standing on the known carbamoyl FAAH inhibitor URB597. Structural modifications led to the recognition of compound 22 that inhibited human recombinant FAAH (hrFAAH) in the low nanomolar range (IC50 = 11 nM). The most active compounds of this series showed significant selectivity toward monoacylglycerol lipase (MAGL) enzyme. In addition, molecular modeling and reversibility behavior of the new class of FAAH inhibitors are presented in this article. PMID:26002335

  8. Natural fatty acid synthase inhibitors as potent therapeutic agents for cancers: A review.

    PubMed

    Zhang, Jia-Sui; Lei, Jie-Ping; Wei, Guo-Qing; Chen, Hui; Ma, Chao-Ying; Jiang, He-Zhong

    2016-09-01

    Context Fatty acid synthase (FAS) is the only mammalian enzyme to catalyse the synthesis of fatty acid. The expression level of FAS is related to cancer progression, aggressiveness and metastasis. In recent years, research on natural FAS inhibitors with significant bioactivities and low side effects has increasingly become a new trend. Herein, we present recent research progress on natural fatty acid synthase inhibitors as potent therapeutic agents. Objective This paper is a mini overview of the typical natural FAS inhibitors and their possible mechanism of action in the past 10 years (2004-2014). Method The information was collected and compiled through major databases including Web of Science, PubMed, and CNKI. Results Many natural products induce cancer cells apoptosis by inhibiting FAS expression, with fewer side effects than synthetic inhibitors. Conclusion Natural FAS inhibitors are widely distributed in plants (especially in herbs and foods). Some natural products (mainly phenolics) possessing potent biological activities and stable structures are available as lead compounds to synthesise promising FAS inhibitors. PMID:26864638

  9. Inhibitors of fatty acid biosynthesis in sunflower seeds.

    PubMed

    Pleite, Rafael; Martínez-Force, Enrique; Garcés, Rafael

    2006-09-01

    During de novo fatty acid synthesis in sunflower seeds, saturated fatty acid production is influenced by the competition between the enzymes of the principal pathways and the saturated acyl-ACP thioesterases. Genetic backgrounds with more efficient saturated acyl-ACP thioesterase alleles only express their phenotypic effects when the alleles for the enzymes in the main pathway are less efficient. For this reason, we studied the incorporation of [2-(14)C]acetate into the lipids of developing sunflower seeds (Helianthus annuus L.) from several mutant lines in vivo. The labelling of different triacylglycerol fatty acids in different oilseed mutants reflects the fatty acid composition of the seed and supports the channelling theory of fatty acid biosynthesis. Incubation with methyl viologen diminished the conversion of stearoyl-ACP to oleoyl-ACP in vivo through a decrease in the available reductant power. In turn, this led to the accumulation of stearoyl-ACP to the levels detected in seeds from high stearic acid mutants. The concomitant reduction of oleoyl-ACP content inside the plastid allowed us to study the activity of acyl-ACP thioesterases on saturated fatty acids. In these mutants, we verified that the accumulation of saturated fatty acids requires efficient thioesterase activity on saturated-ACPs. By studying the effects of cerulenin on the in vivo incorporation of [2-(14)C]acetate into lipids and on the in vitro activity of beta-ketoacyl-ACP synthase II, we found that elongation to very long chain fatty acids can occur both inside and outside of the plastid in sunflower seeds. PMID:16500723

  10. Ferulic acid in combination with PARP inhibitor sensitizes breast cancer cells as chemotherapeutic strategy.

    PubMed

    Choi, Young Eun; Park, Eunmi

    2015-03-13

    Homologous-recombination (HR)-dependent repair defective cells are hypersensitive to poly (ADP-ribose) polymerase (PARP) inhibitors. Combinations of defective HR pathway and PARP inhibitors have been an effective chemotherapeutic modality. We previously showed that knockdown of the WD40-repeat containing protein, Uaf1, causes an HR repair defect in mouse embryo fibroblast cells and therefore, increases sensitivity to PARP inhibitor, ABT-888. Similarly, here, we show that ferulic acid reduces HR repair, inhibits RAD 51 foci formation, and accumulates γ-H2AX in breast cancer cells. Moreover, ferulic acid, when combined with ABT-888, renders breast cancer cells become hypersensitive to ABT-888. Our study indicates that ferulic acid in combination with ABT-888 treatment may serve as an effective combination chemotherapeutic agent as a natural bioactive compound. PMID:25677620

  11. Optimization of amino acid thioesters as inhibitors of metallo-β-lactamase L1.

    PubMed

    Liu, Xiao-Long; Yang, Ke-Wu; Zhang, Yue-Juan; Ge, Ying; Xiang, Yang; Chang, Ya-Nan; Oelschlaeger, Peter

    2016-10-01

    The emergence of antibiotic resistance caused by metallo-β-lactamases (MβLs) is a global public health problem. Recently, we found amino acid thioesters to be a highly promising scaffold for inhibitors of the MβL L1. In order to optimize this series of inhibitors, nine new amino acid thioesters were developed by modifying the substituents on the N-terminus of the thioesters and the groups representing the amino acid side chain. Biological activity assays indicate that all of them are very potent inhibitors of L1 with an IC50 value range of 20-600nM, lower than those of most of the previously reported inhibitors of this scaffold. Analysis of structure-activity relationship reveals that big hydrophobic substituents on the N-terminus and a methionine amino acid side chain improves inhibitory activity of the thioesters. All these inhibitors are able to restore antibacterial activity of a β-lactam antibiotic against Escherichia coli BL21(DE3) cells producing L1 to that against E. coli cells lacking a β-lactamase. Docking studies reveal that a large N-terminal hydrophobic group results in a slightly different binding mode than smaller hydrophobic groups at the same position. PMID:27595424

  12. Zaragozic acids: a family of fungal metabolites that are picomolar competitive inhibitors of squalene synthase.

    PubMed

    Bergstrom, J D; Kurtz, M M; Rew, D J; Amend, A M; Karkas, J D; Bostedor, R G; Bansal, V S; Dufresne, C; VanMiddlesworth, F L; Hensens, O D

    1993-01-01

    Three closely related fungal metabolites, zaragozic acids A, B, and C, that are potent inhibitors of squalene synthase have been isolated and characterized. Zaragozic acids A, B, and C were produced from an unidentified sterile fungal culture, Sporormiella intermedia, and Leptodontium elatius, respectively. The structures of the zaragozic acids and their trimethyl esters were determined by a combination of physical and chemical techniques. The zaragozic acids are characterized by a novel 2,8-dioxobicyclo[3.2.1]octane-4,6,7- trihydroxyl-3,4,5-tricarboxylic acid core and differ from each other in the structures of the 6-acyl and 1-alkyl side chains. They were found to be potent competitive inhibitors of rat liver squalene synthase with apparent Ki values of 78 pM, 29 pM, and 45 pM, respectively. They inhibited cholesterol synthesis in Hep G2 cells, and zaragozic acid A was an inhibitor of acute hepatic cholesterol synthesis in the mouse (50% inhibitory dose of 200 micrograms/kg of body weight). Inhibition of squalene synthase in cells and in vivo was accompanied by an accumulation of label from [3H]mevalonate into farnesyl diphosphate, farnesol, and organic acids. These data indicate that the zaragozic acids are a previously unreported class of therapeutic agents with potential for the treatment of hypercholesterolemia. PMID:8419946

  13. Arginase, Arginine Decarboxylase, Ornithine Decarboxylase, and Polyamines in Tomato Ovaries (Changes in Unpollinated Ovaries and Parthenocarpic Fruits Induced by Auxin or Gibberellin).

    PubMed Central

    Alabadi, D.; Aguero, M. S.; Perez-Amador, M. A.; Carbonell, J.

    1996-01-01

    Arginase (EC 3.5.3.1) activity has been found in the ovaries and Young fruits of tomato (Lycopersicon esculentum Mill. cv Rutgers).Changes in arginase, arginine decarboxylase (EC 4.1.1.19), and ornithine decarboxylase activity (EC 4.1.1.17) and levels of free and conjugated putrescine, spermidine, and spermine were determined in unpollinated ovaries and in parthenocarpic fruits during the early stages of development induced by 2,4-dichlorophenoxyacetic acid (2,4-D) or gibberellic acid (GA3). Levels of arginase, free spermine, and conjugates of the three polyamines were constant in unpollinated ovaries and characteristic of a presenescent step. A marked decrease in arginase activity, free spermine, and polyamine conjugates was associated with the initiation of fruit growth due to cell division, and when cell expansion was initiated, the absence of arginase indicated a redirection of nitrogen metabolism to the synthesis of arginine. A transient increase in arginine decarboxylase and ornithine decarboxylase was also observed in 2,4-D-induced fruits. In general, 2,4-D treatments produced faster changes than GA3, and without treatment, unpollinated ovaries developed only slightly and senescence was hardly visible. Sensitivity to 2,4-D and GA3 treatment remained for at least 2 weeks postanthesis. PMID:12226441

  14. Inhibitors

    MedlinePlus

    ... Community Counts Blood Safety Inhibitors Articles & Key Findings Free Materials Videos Starting the Conversation Playing it Safe A Look at Hemophilia Joint Range of Motion My Story Links to Other Websites ...

  15. Ornithine Decarboxylase Activity Is Required for Prostatic Budding in the Developing Mouse Prostate

    PubMed Central

    Gamat, Melissa; Malinowski, Rita L.; Parkhurst, Linnea J.; Steinke, Laura M.; Marker, Paul C.

    2015-01-01

    The prostate is a male accessory sex gland that produces secretions in seminal fluid to facilitate fertilization. Prostate secretory function is dependent on androgens, although the mechanism by which androgens exert their effects is still unclear. Polyamines are small cationic molecules that play pivotal roles in DNA transcription, translation and gene regulation. The rate-limiting enzyme in polyamine biosynthesis is ornithine decarboxylase, which is encoded by the gene Odc1. Ornithine decarboxylase mRNA decreases in the prostate upon castration and increases upon administration of androgens. Furthermore, testosterone administered to castrated male mice restores prostate secretory activity, whereas administering testosterone and the ornithine decarboxylase inhibitor D,L-α-difluromethylornithine (DFMO) to castrated males does not restore prostate secretory activity, suggesting that polyamines are required for androgens to exert their effects. To date, no one has examined polyamines in prostate development, which is also androgen dependent. In this study, we showed that ornithine decarboxylase protein was expressed in the epithelium of the ventral, dorsolateral and anterior lobes of the adult mouse prostate. Ornithine decarboxylase protein was also expressed in the urogenital sinus (UGS) epithelium of the male and female embryo prior to prostate development, and expression continued in prostatic epithelial buds as they emerged from the UGS. Inhibiting ornithine decarboxylase using DFMO in UGS organ culture blocked the induction of prostatic buds by androgens, and significantly decreased expression of key prostate transcription factor, Nkx3.1, by androgens. DFMO also significantly decreased the expression of developmental regulatory gene Notch1. Other genes implicated in prostatic development including Sox9, Wif1 and Srd5a2 were unaffected by DFMO. Together these results indicate that Odc1 and polyamines are required for androgens to exert their effect in mediating

  16. Ornithine Decarboxylase Activity Is Required for Prostatic Budding in the Developing Mouse Prostate.

    PubMed

    Gamat, Melissa; Malinowski, Rita L; Parkhurst, Linnea J; Steinke, Laura M; Marker, Paul C

    2015-01-01

    The prostate is a male accessory sex gland that produces secretions in seminal fluid to facilitate fertilization. Prostate secretory function is dependent on androgens, although the mechanism by which androgens exert their effects is still unclear. Polyamines are small cationic molecules that play pivotal roles in DNA transcription, translation and gene regulation. The rate-limiting enzyme in polyamine biosynthesis is ornithine decarboxylase, which is encoded by the gene Odc1. Ornithine decarboxylase mRNA decreases in the prostate upon castration and increases upon administration of androgens. Furthermore, testosterone administered to castrated male mice restores prostate secretory activity, whereas administering testosterone and the ornithine decarboxylase inhibitor D,L-α-difluromethylornithine (DFMO) to castrated males does not restore prostate secretory activity, suggesting that polyamines are required for androgens to exert their effects. To date, no one has examined polyamines in prostate development, which is also androgen dependent. In this study, we showed that ornithine decarboxylase protein was expressed in the epithelium of the ventral, dorsolateral and anterior lobes of the adult mouse prostate. Ornithine decarboxylase protein was also expressed in the urogenital sinus (UGS) epithelium of the male and female embryo prior to prostate development, and expression continued in prostatic epithelial buds as they emerged from the UGS. Inhibiting ornithine decarboxylase using DFMO in UGS organ culture blocked the induction of prostatic buds by androgens, and significantly decreased expression of key prostate transcription factor, Nkx3.1, by androgens. DFMO also significantly decreased the expression of developmental regulatory gene Notch1. Other genes implicated in prostatic development including Sox9, Wif1 and Srd5a2 were unaffected by DFMO. Together these results indicate that Odc1 and polyamines are required for androgens to exert their effect in mediating

  17. Complete amino acid sequence of the lentil trypsin-chymotrypsin inhibitor LCI-1.7 and a discussion of atypical binding sites of Bowman-Birk inhibitors.

    PubMed

    Weder, Jürgen K P; Hinkers, Sabine C

    2004-06-30

    The complete primary structure of the lentil (Lens culinaris) trypsin-chymotrypsin inhibitor LCI-1.7 was determined by conventional methods in order to find relationships between partial sequences and the difference in action against human and bovine chymotrypsin. As other Bowman-Birk type inhibitors, LCI-1.7 contained 68 amino acid residues, seven disulfide bridges, and two reactive sites, Arg16-Ser17 for trypsin and Tyr42-Ser43 for chymotrypsin. Evaluation of sequence homologies showed that it belonged to the group III Bowman-Birk inhibitors. The atypical additional binding site of LCI-1.7 for human chymotrypsin was discussed and compared with such binding sites of two other Bowman-Birk inhibitors, the Bowman-Birk soybean proteinase inhibitor BBI, and the lima bean proteinase inhibitor LBI I, for human and bovine trypsin and chymotrypsin. A concept to reduce the action of these inhibitors against human enzymes by genetic engineering was proposed. PMID:15212472

  18. Scoparic acid A, a beta-glucuronidase inhibitor from Scoparia dulcis.

    PubMed

    Hayashi, T; Kawasaki, M; Okamura, K; Tamada, Y; Morita, N; Tezuka, Y; Kikuchi, T; Miwa, Y; Taga, T

    1992-12-01

    The 70% EtOH extract of Scoparia dulcis showed inhibitory activity against beta-glucuronidase from bovine liver. Bioassay-directed fractionation of the active extract led to the isolation of three labdane-type diterpene acids, scoparic acid A [1] [6-benzoyl-12-hydroxy-labda-8(17), 13-dien-18-oic acid], scoparic acid B [2] [6-benzoyl-14,15-dinor-13-oxo-8(17)-labden-18-oic acid], and scoparic acid C [3] [6-benzoyl-15-nor-14-oxo-8(17)-labden-18-oic acid], the structures of which were established by spectral means, including X-ray analysis. Scoparic acid A was found to be a potent beta-glucuronidase inhibitor. PMID:1294695

  19. Advances in the discovery of N-acylethanolamine acid amidase inhibitors.

    PubMed

    Bandiera, Tiziano; Ponzano, Stefano; Piomelli, Daniele

    2014-08-01

    N-Acylethanolamine acid amidase (NAAA) is a cysteine amidase that hydrolyzes saturated or monounsaturated fatty acid ethanolamides, such as palmitoylethanolamide (PEA) and oleoylethanolamide (OEA). PEA has been shown to exert analgesic and anti-inflammatory effects by engaging peroxisome proliferator-activated receptor-α. Like other fatty acid ethanolamides, PEA is not stored in cells, but produced on demand from cell membrane precursors, and its actions are terminated by intracellular hydrolysis by either fatty acid amide hydrolase or NAAA. Endogenous levels of PEA and OEA have been shown to decrease during inflammation. Modulation of the tissue levels of PEA by inhibition of enzymes responsible for the breakdown of this lipid mediator may represent therefore a new therapeutic strategy for the treatment of pain and inflammation. While a large number of inhibitors of fatty acid amide hydrolase have been discovered, few compounds have been reported to inhibit NAAA activity. Here, we describe the most representative NAAA inhibitors and briefly highlight their pharmacological profile. A recent study has shown that a NAAA inhibitor attenuated heat hyperalgesia and mechanical allodynia caused by local inflammation or nerve damage in animal models of pain and inflammation. This finding encourages further exploration of the pharmacology of NAAA inhibitors. PMID:24798679

  20. Impacts of lignocellulose-derived inhibitors on L-lactic acid fermentation by Rhizopus oryzae.

    PubMed

    Zhang, Li; Li, Xin; Yong, Qiang; Yang, Shang-Tian; Ouyang, Jia; Yu, Shiyuan

    2016-03-01

    Inhibitors generated in the pretreatment and hydrolysis of corn stover and corn cob were identified. In general, they inhibited cell growth, lactate dehydrogenase, and lactic acid production but with less or no adverse effect on alcohol dehydrogenase and ethanol production in batch fermentation by Rhizopus oryzae. Furfural and 5-hydroxymethyl furfural (HMF) were highly toxic at 0.5-1 g L(-1), while formic and acetic acids at less than 4 g L(-1) and levulinic acid at 10 g L(-1) were not toxic. Among the phenolic compounds at 1 g L(-1), trans-cinnamic acid and syringaldehyde had the highest toxicity while syringic, ferulic and p-coumaric acids were not toxic. Although these inhibitors were present at concentrations much lower than their separately identified toxic levels, lactic acid fermentation with the hydrolysates showed much inferior performance compared to the control without inhibitor, suggesting synergistic or compounded effects of the lignocellulose-degraded compounds on inhibiting lactic acid fermentation. PMID:26724548

  1. Soraphen A, an inhibitor of acetyl CoA carboxylase activity, interferes with fatty acid elongation

    PubMed Central

    Jump, Donald B.; Torres-Gonzalez, Moises; Olson, L. Karl

    2010-01-01

    Acetyl CoA carboxylase (ACC1 & ACC2) generates malonyl CoA, a substrate for de novo lipogenesis (DNL) and an inhibitor of mitochondrial fatty acid β-oxidation (FAO). Malonyl CoA is also a substrate for microsomal fatty acid elongation, an important pathway for saturated (SFA), mono- (MUFA) and polyunsaturated fatty acid (PUFA) synthesis. Despite the interest in ACC as a target for obesity and cancer therapy, little attention has been given to the role ACC plays in long chain fatty acid synthesis. This report examines the effect of pharmacological inhibition of ACC on DNL & palmitate (16:0) and linoleate (18:2,n-6) metabolism in HepG2 and LnCap cells. The ACC inhibitor, soraphen A, lowers cellular malonyl CoA, attenuates DNL and the formation of fatty acid elongation products derived from exogenous fatty acids, i.e., 16:0 & 18:2,n-6; IC50 ~ 5 nM. Elevated expression of fatty acid elongases (Elovl5, Elovl6) or desaturases (FADS1, FADS2) failed to override the soraphen A effect on SFA, MUFA or PUFA synthesis. Inhibition of fatty acid elongation leads to the accumulation of 16- and 18-carbon unsaturated fatty acids derived from 16:0 and 18:2,n-6, respectively. Pharmacological inhibition of ACC activity will not only attenuate DNL and induce FAO, but will also attenuate the synthesis of very long chain saturated, mono- and polyunsaturated fatty acids. PMID:21184748

  2. Structural Requirements of Histone Deacetylase Inhibitors: SAHA Analogs Modified on the Hydroxamic Acid.

    PubMed

    Bieliauskas, Anton V; Weerasinghe, Sujith V W; Negmeldin, Ahmed T; Pflum, Mary Kay H

    2016-05-01

    Histone deacetylase (HDAC) proteins have emerged as targets for anti-cancer therapeutics, with several inhibitors used in the clinic, including suberoylanilide hydroxamic acid (SAHA, vorinostat). Because SAHA and many other inhibitors target all or most of the 11 human HDAC proteins, the creation of selective inhibitors has been studied intensely. Recently, inhibitors selective for HDAC1 and HDAC2 were reported where selectivity was attributed to interactions between substituents on the metal binding moiety of the inhibitor and residues in the 14-Å internal cavity of the HDAC enzyme structure. Based on this earlier work, we synthesized and tested SAHA analogs with substituents on the hydroxamic acid metal binding moiety. The N-substituted SAHA analogs displayed reduced potency and solubility, but greater selectivity, compared to SAHA. Docking studies suggested that the N-substituent accesses the 14-Å internal cavity to impart preferential inhibition of HDAC1. These studies with N-substituted SAHA analogs are consistent with the strategy exploiting the 14-Å internal cavity of HDAC proteins to create HDAC1/2 selective inhibitors. PMID:27062198

  3. Massive production of farnesol-derived dicarboxylic acids in mice treated with the squalene synthase inhibitor zaragozic acid A.

    PubMed

    Vaidya, S; Bostedor, R; Kurtz, M M; Bergstrom, J D; Bansal, V S

    1998-07-01

    The zaragozic acids are potent inhibitors of squalene synthase. In vivo studies in mice confirmed our earlier observations that inhibition of squalene synthase by zaragozic acid A was accompanied by an increase in the incorporation of label from [3H]mevalonate into farnesyl-diphosphate (FPP)-derived isoprenoic acids (J. D. Bergstrom et al., 1993, Proc. Natl. Acad. Sci. USA 90, 80-84). Farnesyl-diphosphate-derived metabolites appear transiently in the liver. We were unable to detect any farnesol formation in the zaragozic acid-treated animals which indicates that FPP is readily converted to farnesoic acid and dicarboxylic acids in the liver. These metabolites were found to be produced only in the liver and not in the kidney. trans-3,7-Dimethyl-2-octaen-1,8-dioic acid and 3, 7-dimethyloctan-1,8-dioic acid were identified as the major end products of farnesyl-diphosphate metabolism in the urine of mice treated with zaragozic acid A. Quantitative analysis of these FPP-derived dicarboxylic acids by gas-liquid chromatography revealed that approximately 11 mg of total dicarboxylic acids is excreted per day into the urine of a mouse after 3 days of treatment with zaragozic acid A. PMID:9647670

  4. Binding of [alpha, alpha]-Disubstituted Amino Acids to Arginase Suggests New Avenues for Inhibitor Design

    SciTech Connect

    Ilies, Monica; Di Costanzo, Luigi; Dowling, Daniel P.; Thorn, Katherine J.; Christianson, David W.

    2011-10-21

    Arginase is a binuclear manganese metalloenzyme that hydrolyzes L-arginine to form L-ornithine and urea, and aberrant arginase activity is implicated in various diseases such as erectile dysfunction, asthma, atherosclerosis, and cerebral malaria. Accordingly, arginase inhibitors may be therapeutically useful. Continuing our efforts to expand the chemical space of arginase inhibitor design and inspired by the binding of 2-(difluoromethyl)-L-ornithine to human arginase I, we now report the first study of the binding of {alpha},{alpha}-disubstituted amino acids to arginase. Specifically, we report the design, synthesis, and assay of racemic 2-amino-6-borono-2-methylhexanoic acid and racemic 2-amino-6-borono-2-(difluoromethyl)hexanoic acid. X-ray crystal structures of human arginase I and Plasmodium falciparum arginase complexed with these inhibitors reveal the exclusive binding of the L-stereoisomer; the additional {alpha}-substituent of each inhibitor is readily accommodated and makes new intermolecular interactions in the outer active site of each enzyme. Therefore, this work highlights a new region of the protein surface that can be targeted for additional affinity interactions, as well as the first comparative structural insights on inhibitor discrimination between a human and a parasitic arginase.

  5. Curcumin Derivatives as Green Corrosion Inhibitors for α-Brass in Nitric Acid Solution

    NASA Astrophysics Data System (ADS)

    Fouda, A. S.; Elattar, K. M.

    2012-11-01

    1,7- Bis-(4-hydroxy-3-methoxy-phenyl)-hepta-1,6-diene-4-arylazo-3,5-dione I-V have been investigated as corrosion inhibitors for α-brass in 2 M nitric acid solution using weight-loss and galvanostatic polarization techniques. The efficiency of the inhibitors increases with the increase in the inhibitor concentration but decreases with a rise in temperature. The conjoint effect of the curcumin derivatives and KSCN has also been studied. The apparent activation energy ( E a*) and other thermodynamic parameters for the corrosion process have also been calculated. The galvanostatic polarization data indicated that the inhibitors were of mixed-type, but the cathode is more polarized than the anode. The slopes of the cathodic and anodic Tafel lines ( b c and b a) are maintained approximately equal for various inhibitor concentrations. However, the value of the Tafel slopes increases together as inhibitor concentration increases. The adsorption of these compounds on α-brass surface has been found to obey the Frumkin's adsorption isotherm. The mechanism of inhibition was discussed in the light of the chemical structure of the undertaken inhibitors.

  6. Self-consistent synthesis of the squalene synthase inhibitor zaragozic acid C via controlled oligomerization.

    PubMed

    Nicewicz, David A; Satterfield, Andrew D; Schmitt, Daniel C; Johnson, Jeffrey S

    2008-12-24

    Despite the prevalence of repeating subunits in chiral natural products, stereocontrolled oligomerization is a largely unexplored strategy for construction of carbon skeletal frameworks. This report describes the use of silyl glyoxylates as dipolar glycolic acid synthons in a controlled oligomerization reaction for the efficient construction of the squalene synthase inhibitor zaragozic acid C. This new methodology allows rapid, stereocontrolled formation of the carbon skeleton with a desirable protecting group scheme while minimizing functional group repair and oxidation state manipulations. PMID:19053214

  7. Benzoxazolone Carboxamides as Potent Acid Ceramidase Inhibitors: Synthesis and Structure-Activity Relationship (SAR) Studies.

    PubMed

    Bach, Anders; Pizzirani, Daniela; Realini, Natalia; Vozella, Valentina; Russo, Debora; Penna, Ilaria; Melzig, Laurin; Scarpelli, Rita; Piomelli, Daniele

    2015-12-10

    Ceramides are lipid-derived intracellular messengers involved in the control of senescence, inflammation, and apoptosis. The cysteine amidase, acid ceramidase (AC), hydrolyzes these substances into sphingosine and fatty acid and, by doing so, regulates their signaling activity. AC inhibitors may be useful in the treatment of pathological conditions, such as cancer, in which ceramide levels are abnormally reduced. Here, we present a systematic SAR investigation of the benzoxazolone carboxamides, a recently described class of AC inhibitors that display high potency and systemic activity in mice. We examined a diverse series of substitutions on both benzoxazolone ring and carboxamide side chain. Several modifications enhanced potency and stability, and one key compound with a balanced activity-stability profile (14) was found to inhibit AC activity in mouse lungs and cerebral cortex after systemic administration. The results expand our arsenal of AC inhibitors, thereby facilitating the use of these compounds as pharmacological tools and their potential development as drug leads. PMID:26560855

  8. Bis(aminomethyl)phosphinic Acid, a Highly Promising Scaffold for the Development of Bacterial Urease Inhibitors

    PubMed Central

    2014-01-01

    Inhibitors of bacterial ureases are considered to be promising compounds in the treatment of infections caused by Helicobacter pylori in the gastric tract and/or by urealytic bacteria (e.g., Proteus species) in the urinary tract. A new, extended transition state scaffold, bis(aminomethyl)phosphinic acid, was successfully explored for the construction of effective enzyme inhibitors. A reliable methodology for the synthesis of phosphinate analogues in a three-component Mannich-type reaction was elaborated. The obtained molecules were assayed against ureases purified from Sporosarcina pasteurii and Proteus mirabilis, and aminomethyl(N-n-hexylaminomethyl)phosphinic acid was found to be the most potent inhibitor, with a Ki = 108 nM against the S. pasteurii enzyme. PMID:25699141

  9. Bis(aminomethyl)phosphinic Acid, a Highly Promising Scaffold for the Development of Bacterial Urease Inhibitors.

    PubMed

    Macegoniuk, Katarzyna; Dziełak, Anna; Mucha, Artur; Berlicki, Łukasz

    2015-02-12

    Inhibitors of bacterial ureases are considered to be promising compounds in the treatment of infections caused by Helicobacter pylori in the gastric tract and/or by urealytic bacteria (e.g., Proteus species) in the urinary tract. A new, extended transition state scaffold, bis(aminomethyl)phosphinic acid, was successfully explored for the construction of effective enzyme inhibitors. A reliable methodology for the synthesis of phosphinate analogues in a three-component Mannich-type reaction was elaborated. The obtained molecules were assayed against ureases purified from Sporosarcina pasteurii and Proteus mirabilis, and aminomethyl(N-n-hexylaminomethyl)phosphinic acid was found to be the most potent inhibitor, with a K i = 108 nM against the S. pasteurii enzyme. PMID:25699141

  10. Beyond gastric acid reduction: Proton pump inhibitors induce heme oxygenase-1 in gastric and endothelial cells

    SciTech Connect

    Becker, Jan C. . E-mail: beckeja@uni-muenster.de; Grosser, Nina; Waltke, Christian; Schulz, Stephanie; Erdmann, Kati; Domschke, Wolfram; Schroeder, Henning; Pohle, Thorsten

    2006-07-07

    Proton pump inhibitors (PPIs) have been demonstrated to prevent gastric mucosal injury by mechanisms independent of acid inhibition. Here we demonstrate that both omeprazole and lansoprazole protect human gastric epithelial and endothelial cells against oxidative stress. This effect was abrogated in the presence of the heme oxygenase-1 (HO-1) inhibitor ZnBG. Exposure to either PPI resulted in a strong induction of HO-1 expression on mRNA and protein level, and led to an increased activity of this enzyme. Expression of cyclooxygenase isoforms 1 and 2 remained unaffected, and COX-inhibitors did not antagonize HO-1 induction by PPIs. Our results suggest that the antioxidant defense protein HO-1 is a target of PPIs in both endothelial and gastric epithelial cells. HO-1 induction might account for the gastroprotective effects of PPIs independently of acid inhibition, especially in NSAID gastropathy. Moreover, our findings provide additional perspectives for a possible but yet unexplored use of PPIs in vasoprotection.

  11. Trypsin inhibitors from ridged gourd (Luffa acutangula Linn.) seeds: purification, properties, and amino acid sequences.

    PubMed

    Haldar, U C; Saha, S K; Beavis, R C; Sinha, N K

    1996-02-01

    Two trypsin inhibitors, LA-1 and LA-2, have been isolated from ridged gourd (Luffa acutangula Linn.) seeds and purified to homogeneity by gel filtration followed by ion-exchange chromatography. The isoelectric point is at pH 4.55 for LA-1 and at pH 5.85 for LA-2. The Stokes radius of each inhibitor is 11.4 A. The fluorescence emission spectrum of each inhibitor is similar to that of the free tyrosine. The biomolecular rate constant of acrylamide quenching is 1.0 x 10(9) M-1 sec-1 for LA-1 and 0.8 x 10(9) M-1 sec-1 for LA-2 and that of K2HPO4 quenching is 1.6 x 10(11) M-1 sec-1 for LA-1 and 1.2 x 10(11) M-1 sec-1 for LA-2. Analysis of the circular dichroic spectra yields 40% alpha-helix and 60% beta-turn for La-1 and 45% alpha-helix and 55% beta-turn for LA-2. Inhibitors LA-1 and LA-2 consist of 28 and 29 amino acid residues, respectively. They lack threonine, alanine, valine, and tryptophan. Both inhibitors strongly inhibit trypsin by forming enzyme-inhibitor complexes at a molar ratio of unity. A chemical modification study suggests the involvement of arginine of LA-1 and lysine of LA-2 in their reactive sites. The inhibitors are very similar in their amino acid sequences, and show sequence homology with other squash family inhibitors. PMID:8924202

  12. Synergism of antifungal activity between mitochondrial respiration inhibitors and kojic acid

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Co-application of certain types of compounds with conventional antimicrobial drugs results in the enhancement of efficacy of drugs through a mechanism termed chemosensitization. We show that kojic acid (KA), a natural product, is a potent chemosensitizer to complex III inhibitors of mitochondrial re...

  13. The identification and optimization of 2,4-diketobutyric acids as flap endonuclease 1 inhibitors.

    PubMed

    Tumey, L Nathan; Huck, Bayard; Gleason, Elizabeth; Wang, Jianmin; Silver, Daniel; Brunden, Kurt; Boozer, Sherry; Rundlett, Stephen; Sherf, Bruce; Murphy, Steven; Bailey, Andrew; Dent, Tom; Leventhal, Christina; Harrington, John; Bennani, Youssef L

    2004-10-01

    There have been several recent reports of chemopotentiation via inhibition of DNA repair processes. Flap endonuclease 1 (FEN1) is a key enzyme involved in base excision repair (BER), a primary pathway utilized by mammalian cells to repair DNA damage. In this report, we describe the identification and SAR of a series of 2,4-diketobutyric acid FEN1 inhibitors. PMID:15341951

  14. HALOACETIC ACIDS AND KINASE INHIBITORS PERTURB MOUSE NEURAL CREST CELLS IN VITRO

    EPA Science Inventory

    HUNTER, E.S.1, J. SMITH2, J. ANDREWS1. 1 Reproductive Toxicology Division, NHEERL, US EPA, Research Triangle Park and 2 Department of Cell and Developmental Biology, UNC-CH, Chapel Hill, North Carolina. Haloacetic acids and kinase inhibitors perturb mouse neural crest cells in vi...

  15. Hydroxyindole Carboxylic Acid-Based Inhibitors for Receptor-Type Protein Tyrosine Protein Phosphatase Beta

    PubMed Central

    Zeng, Li-Fan; Zhang, Ruo-Yu; Bai, Yunpeng; Wu, Li; Gunawan, Andrea M.

    2014-01-01

    Abstract Aims: Protein tyrosine phosphatases (PTPs) play an important role in regulating a wide range of cellular processes. Understanding the role of PTPs within these processes has been hampered by a lack of potent and selective PTP inhibitors. Generating potent and selective probes for PTPs remains a significant challenge because of the highly conserved and positively charged PTP active site that also harbors a redox-sensitive Cys residue. Results: We describe a facile method that uses an appropriate hydroxyindole carboxylic acid to anchor the inhibitor to the PTP active site and relies on the secondary binding elements introduced through an amide-focused library to enhance binding affinity for the target PTP and to impart selectivity against off-target phosphatases. Here, we disclose a novel series of hydroxyindole carboxylic acid-based inhibitors for receptor-type tyrosine protein phosphatase beta (RPTPβ), a potential target that is implicated in blood vessel development. The representative RPTPβ inhibitor 8b-1 (L87B44) has an IC50 of 0.38 μM and at least 14-fold selectivity for RPTPβ over a large panel of PTPs. Moreover, 8b-1 also exhibits excellent cellular activity and augments growth factor signaling in HEK293, MDA-MB-468, and human umbilical vein endothelial cells. Innovation: The bicyclic salicylic acid pharmacophore-based focused library approach may provide a potential solution to overcome the bioavailability issue that has plagued the PTP drug discovery field for many years. Conclusion: A novel method is described for the development of bioavailable PTP inhibitors that utilizes bicyclic salicylic acid to anchor the inhibitors to the active site and peripheral site interactions to enhance binding affinity and selectivity. Antioxid. Redox Signal. 20, 2130–2140. PMID:24180557

  16. Fatty acid amide hydrolase inhibitors confer anti-invasive and antimetastatic effects on lung cancer cells

    PubMed Central

    Winkler, Katrin; Ramer, Robert; Dithmer, Sophie; Ivanov, Igor; Merkord, Jutta; Hinz, Burkhard

    2016-01-01

    Inhibition of endocannabinoid degradation has been suggested as tool for activation of endogenous tumor defense. One of these strategies lies in blockade of fatty acid amide hydrolase (FAAH) which catalyzes the degradation of endocannabinoids (anandamide [AEA], 2-arachidonoylglycerol [2-AG]) and endocannabinoid-like substances (N-oleoylethanolamine [OEA], N-palmitoylethanolamine [PEA]). This study addressed the impact of two FAAH inhibitors (arachidonoyl serotonin [AA-5HT], URB597) on A549 lung cancer cell metastasis and invasion. LC-MS analyses revealed increased levels of FAAH substrates (AEA, 2-AG, OEA, PEA) in cells incubated with either FAAH inhibitor. In athymic nude mice FAAH inhibitors were shown to elicit a dose-dependent antimetastatic action yielding a 67% and 62% inhibition of metastatic lung nodules following repeated administration of 15 mg/kg AA-5HT and 5 mg/kg URB597, respectively. In vitro, a concentration-dependent anti-invasive action of either FAAH inhibitor was demonstrated, accompanied with upregulation of tissue inhibitor of matrix metalloproteinases-1 (TIMP-1). Using siRNA approaches, a causal link between the TIMP-1-upregulating and anti-invasive action of FAAH inhibitors was confirmed. Moreover, knockdown of FAAH by siRNA was shown to confer decreased cancer cell invasiveness and increased TIMP-1 expression. Inhibitor experiments point toward a role of CB2 and transient receptor potential vanilloid 1 in conferring anti-invasive effects of FAAH inhibitors and FAAH siRNA. Finally, antimetastatic and anti-invasive effects were confirmed for all FAAH substrates with AEA and OEA causing a TIMP-1-dependent anti-invasive action. Collectively, the present study provides first-time proof for an antimetastatic action of FAAH inhibitors. As mechanism of its anti-invasive properties an upregulation of TIMP-1 was identified. PMID:26930716

  17. Penta- and hexadienoic acid derivatives: a novel series of 5-lipoxygenase inhibitors.

    PubMed

    Malleron, J L; Roussel, G; Gueremy, G; Ponsinet, G; Robin, J L; Terlain, B; Tissieres, J M

    1990-10-01

    The synthesis of a series of pentadienoic and hexadienoic acid derivatives is reported. These compounds were tested as inhibitors of 5-lipoxygenase (5 LO) and cyclooxygenase (CO) in vitro and as inhibitors of arachidonic acid (AA) induced ear edema in mice in vivo. Their potency is compared with that of the standard inhibitors nafazatrom, BW 755C, NDGA, KME4, quercetine, and L 652,243. The most potent compound in vivo, diethyl 2-hydroxy-5-(ethylthio)-2(Z),4(Z)-hexadienedioate (20) inhibited AA-induced ear edema when administered topically or orally, with an ED50 value of 0.01 mg/ear and 20 mg/kg, respectively. Among the standard compounds tested, L 652,243 was the most active compound in this test with an ED50 value of 0.01 mg/ear and 1 mg/kg po, but unlike this compound, 20 is a selective inhibitor of 5-LO (IC50 = 2 microM) without any significant activity against CO (IC50 greater than 50 microM). Most of the other compounds in this series are also selective 5-LO inhibitors. PMID:2213827

  18. Structure-Based Design of Non-Natural Amino Acid Inhibitors of Amyloid Fibrillation

    PubMed Central

    Sievers, Stuart A.; Karanicolas, John; Chang, Howard W.; Zhao, Anni; Jiang, Lin; Zirafi, Onofrio; Stevens, Jason T.; Münch, Jan; Baker, David; Eisenberg, David

    2014-01-01

    Many globular and natively disordered proteins can convert into amyloid fibers. These fibers are associated with numerous pathologies1 as well as with normal cellular functions2,3, and frequently form during protein denaturation4,5. Inhibitors of pathological amyloid fibers could serve as leads for therapeutics, provided the inhibitors were specific enough to avoid interfering with normal processes. Here we show that computer-aided, structure-based design can yield highly specific peptide inhibitors of amyloid formation. Using known atomic structures of segments of amyloid fibers as templates, we have designed and characterized an all D-amino acid inhibitor of fibrillation of the tau protein found in Alzheimer’s disease, and a non-natural L-amino acid inhibitor of an amyloid fiber that enhances sexual transmission of HIV. Our results indicate that peptides from structure-based designs can disrupt the fibrillation of full-length proteins, including those like tau that lack fully ordered native structures. PMID:21677644

  19. Structure-based design of non-natural amino-acid inhibitors of amyloid fibril formation

    SciTech Connect

    Sievers, Stuart A.; Karanicolas, John; Chang, Howard W.; Zhao, Anni; Jiang, Lin; Zirafi, Onofrio; Stevens, Jason T.; Münch, Jan; Baker, David; Eisenberg, David

    2011-09-20

    Many globular and natively disordered proteins can convert into amyloid fibrils. These fibrils are associated with numerous pathologies as well as with normal cellular functions, and frequently form during protein denaturation. Inhibitors of pathological amyloid fibril formation could be useful in the development of therapeutics, provided that the inhibitors were specific enough to avoid interfering with normal processes. Here we show that computer-aided, structure-based design can yield highly specific peptide inhibitors of amyloid formation. Using known atomic structures of segments of amyloid fibrils as templates, we have designed and characterized an all-D-amino-acid inhibitor of the fibril formation of the tau protein associated with Alzheimer's disease, and a non-natural L-amino-acid inhibitor of an amyloid fibril that enhances sexual transmission of human immunodeficiency virus. Our results indicate that peptides from structure-based designs can disrupt the fibril formation of full-length proteins, including those, such as tau protein, that lack fully ordered native structures. Because the inhibiting peptides have been designed on structures of dual-{beta}-sheet 'steric zippers', the successful inhibition of amyloid fibril formation strengthens the hypothesis that amyloid spines contain steric zippers.

  20. Peroxisomal fatty acid oxidation and inhibitors of the mitochondrial carnitine palmitoyltransferase I in isolated rat hepatocytes.

    PubMed Central

    Skorin, C; Necochea, C; Johow, V; Soto, U; Grau, A M; Bremer, J; Leighton, F

    1992-01-01

    Fatty acid oxidation was studied in the presence of inhibitors of carnitine palmitoyltransferase I (CPT I), in normal and in peroxisome-proliferated rat hepatocytes. The oxidation decreased in mitochondria, as expected, but in peroxisomes it increased. These two effects were seen, in variable proportions, with (+)-decanoylcarnitine, 2-tetradecylglycidic acid (TDGA) and etomoxir. The decrease in mitochondrial oxidation (ketogenesis) affected saturated fatty acids with 12 or more carbon atoms, whereas the increase in peroxisomal oxidation (H2O2 production) affected saturated fatty acids with 8 or more carbon atoms. The peroxisomal increase was sensitive to chlorpromazine, a peroxisomal inhibitor. To study possible mechanisms, palmitoyl-, octanoyl- and acetyl-carnitine acyltransferase activities were measured, in homogenates and in subcellular fractions from control and TDGA-treated cells. The palmitoylcarnitine acyltransferase was inhibited, as expected, but the octanoyltransferase activity also decreased. The CoA derivative of TDGA was synthesized and tentatively identified as being responsible for inhibition of the octanoylcarnitine acyltransferase. These results show that inhibitors of the mitochondrial CPT I may also inhibit the peroxisomal octanoyl transferase; they also support the hypothesis that the octanoyltransferase has the capacity to control or regulate peroxisomal fatty acid oxidation. PMID:1736904

  1. Fatty Acid Synthase Inhibitor C75 Ameliorates Experimental Colitis

    PubMed Central

    Matsuo, Shingo; Yang, Weng-Lang; Aziz, Monowar; Kameoka, Shingo; Wang, Ping

    2014-01-01

    Abnormalities of lipid metabolism through overexpression of fatty acid synthase (FASN), which catalyzes the formation of long-chain fatty acids, are associated with the development of inflammatory bowel disease (IBD). C75 is a synthetic α-methylene-γ-butyrolactone compound that inhibits FASN activity. We hypothesized that C75 treatment could effectively reduce the severity of experimental colitis. Male C57BL/6 mice were fed 4% dextran sodium sulfate (DSS) for 7 d. C75 (5 mg/kg body weight) or dimethyl sulfoxide (DMSO) (vehicle) was administered intraperitoneally from d 2 to 6. Clinical parameters were monitored daily. Mice were euthanized on d 8 for histological evaluation and measurements of colon length, chemokine, cytokine and inflammatory mediator expression. C75 significantly reduced body weight loss from 23% to 15% on d 8, compared with the vehicle group. The fecal bleeding, diarrhea and colon histological damage scores in the C75-treated group were significantly lower than scores in the vehicle animals. Colon shortening was significantly improved after C75 treatment. C75 protected colon tissues from DSS-induced apoptosis by inhibiting caspase-3 activity. Macrophage inflammatory protein 2, keratinocyte-derived chemokine, myeloperoxidase activity and proinflammatory cytokines (tumor necrosis factor-α, interleukin [IL]-1β and IL-6) in the colon were significantly downregulated in the C75-treated group, compared with the vehicle group. Treatment with C75 in colitis mice inhibited the elevation of FASN, cyclooxygenase-2 and inducible nitric oxide synthase expression as well as IκB degradation in colon tissues. C75 administration alleviates the severity of colon damage and inhibits the activation of inflammatory pathways in DSS-induced colitis. Thus, inhibition of FASN may represent an attractive therapeutic potential for treating IBD. PMID:24306512

  2. Discovery and molecular basis of potent noncovalent inhibitors of fatty acid amide hydrolase (FAAH)

    PubMed Central

    Min, Xiaoshan; Thibault, Stephen T.; Porter, Amy C.; Gustin, Darin J.; Carlson, Timothy J.; Xu, Haoda; Lindstrom, Michelle; Xu, Guifen; Uyeda, Craig; Ma, Zhihua; Li, Yihong; Kayser, Frank; Walker, Nigel P. C.; Wang, Zhulun

    2011-01-01

    Fatty acid amide hydrolase (FAAH), an amidase-signature family member, is an integral membrane enzyme that degrades lipid amides including the endogenous cannabinoid anandamide and the sleep-inducing molecule oleamide. Both genetic knock out and pharmacological administration of FAAH inhibitors in rodent models result in analgesic, anxiolytic, and antiinflammatory phenotypes. Targeting FAAH activity, therefore, presents a promising new therapeutic strategy for the treatment of pain and other neurological-related or inflammatory disorders. Nearly all FAAH inhibitors known to date attain their binding potency through a reversible or irreversible covalent modification of the nucleophile Ser241 in the unusual Ser-Ser-Lys catalytic triad. Here, we report the discovery and mechanism of action of a series of ketobenzimidazoles as unique and potent noncovalent FAAH inhibitors. Compound 2, a representative of these ketobenzimidazoles, was designed from a series of ureas that were identified from high-throughput screening. While urea compound 1 is characterized as an irreversible covalent inhibitor, the cocrystal structure of FAAH complexed with compound 2 reveals that these ketobenzimidazoles, though containing a carbonyl moiety, do not covalently modify Ser241. These inhibitors achieve potent inhibition of FAAH activity primarily from shape complementarity to the active site and through numerous hydrophobic interactions. These noncovalent compounds exhibit excellent selectivity and good pharmacokinetic properties. The discovery of this distinctive class of inhibitors opens a new avenue for modulating FAAH activity through nonmechanism-based inhibition. PMID:21502526

  3. Structure–Activity Relationships of α-Keto Oxazole Inhibitors of Fatty Acid Amide Hydrolase

    PubMed Central

    Hardouin, Christophe; Kelso, Michael J.; Romero, F. Anthony; Rayl, Thomas J.; Leung, Donmienne; Hwang, Inkyu; Cravatt, Benjamin F.; Boger, Dale L.

    2008-01-01

    A systematic study of the structure–activity relationships (SAR) of 2b (OL-135), a potent inhibitor of fatty acid amide hydrolase (FAAH), is detailed targeting the C2 acyl side chain. A series of aryl replacements or substituents for the terminal phenyl group provided effective inhibitors (e.g., 5c, aryl = 1-napthyl, Ki = 2.6 nM) with 5hh (aryl = 3-Cl-Ph, Ki = 900 pM) being 5-fold more potent than 2b. Conformationally-restricted C2 side chains were examined and many provided exceptionally potent inhibitors of which 11j (ethylbiphenyl side chain) was established to be a 750 pM inhibitor. A systematic series of heteroatoms (O, NMe, S), electron-withdrawing groups (SO, SO2), and amides positioned within and hydroxyl substitutions on the linking side chain were investigated which typically led to a loss in potency. The most tolerant positions provided effective inhibitors (12p, 6-position S, Ki = 3 nM or 13d, 2-position OH, Ki = 8 nM) comparable in potency to 2b. Proteomic-wide screening of selected inhibitors from the systematic series of >100 candidates prepared revealed that they are selective for FAAH over all other mammalian serine proteases. PMID:17559203

  4. Cathepsin D-mediated yolk protein degradation is blocked by acid phosphatase inhibitors.

    PubMed

    Fialho, Eliane; Nakamura, Angelica; Juliano, Luiz; Masuda, Hatisaburo; Silva-Neto, Mário A C

    2005-04-15

    Vitellin (VT) is a lipoglycophosphoprotein stored inside the eggs of every oviparous organism during oogenesis. In the blood-sucking bug Rhodnius prolixus, VT is deposited inside growing oocytes together with two acid hydrolases: acid phosphatase (AP) and cathepsin D (CD). Egg fertilization triggers AP activity and VT proteolysis in vivo [Insect Biochem. Mol. Biol. 2002 (32) 847]. Here, we show that CD is the main protease targeting VT proteolysis during egg development. CD activity in total egg homogenates is blocked by the classical aspartyl protease inhibitor, pepstatin A. Surprisingly, AP inhibitors such as NaF, Na+/K+ tartrate, and inorganic phosphate also block VT proteolysis, whereas this effect is not observed when tyrosine phosphatase inhibitors such as vanadate and phenylarsine oxide or an inhibitor of alkaline phosphatases such as levamisole are used in a VT proteolysis assay. NaF concentrations that block isolated AP activity do not affect the activity of partially purified CD. Therefore, a specific repressor of VT proteolysis must be dephosphorylated by AP in vivo. In conclusion, these results demonstrate for the first time that acid hydrolases act cooperatively to promote yolk degradation during egg development in arthropods. PMID:15797237

  5. Identification of new quinic acid derivatives as histone deacetylase inhibitors by fluorescence-based cellular assay.

    PubMed

    Son, Dohyun; Kim, Chung Sub; Lee, Kang Ro; Park, Hyun-Ju

    2016-05-01

    A fluorescence-based cellular assay system was established to identify potential epigenetic modulator ligands. This assay method is to detect the de-repression of an EGFP reporter in cancer cells by the treatment of HDAC (histone deacetylase) or DNMT (DNA methyltransferase) inhibitor. Using this system, we conducted a preliminary screening of in-house natural product library containing extracts and pure compounds, and identified several active compounds. Among them, novel quinic acid derivatives were recognized as excellent HDAC inhibitors by both enzymatic and cell-based HDAC assays. PMID:26996372

  6. Triacontanol negatively modulates the jasmonic acid-stimulated proteinase inhibitors in tomato (Lycopersicon esculentum).

    PubMed

    Ramanarayan, Krishnamurthy; Swamy, Gangadharamurthy Sivakumar

    2004-04-01

    Triacontanol (TRIA), a long chain aliphatic alcohol (C30H61OH) reverses the effect of jasmonic acid (JA) in inducing proteinase inhibitors (PIs) in tomato leaves. Porcine pancreas trypsin and Spodoptera litura gut proteinases were inhibited in the presence of leaf proteins treated with JA, and TRIA partially reverses this effect. Spodoptera litura larvae fed with tomato leaves treated with JA were reduced in body weight and TRIA is able to partially reverse this JA-induced effect. These results reflect the partial reversal effect of TRIA in down regulating the JA-induced production of proteinase inhibitors. PMID:15128037

  7. 3-Cyano-3-aza-β-amino Acid Derivatives as Inhibitors of Human Cysteine Cathepsins

    PubMed Central

    2014-01-01

    Nitrile-type inhibitors are known to interact with cysteine proteases in a covalent-reversible manner. The chemotype of 3-cyano-3-aza-β-amino acid derivatives was designed in which the N-cyano group is centrally arranged in the molecule to allow for interactions with the nonprimed and primed binding regions of the target enzymes. These compounds were evaluated as inhibitors of the human cysteine cathepsins K, S, B, and L. They exhibited slow-binding behavior and were found to be exceptionally potent, in particular toward cathepsin K, with second-order rate constants up to 52 900 × 103 M–1 s–1. PMID:25313316

  8. Resistance of horse alpha 1-proteinase inhibitor to perchloric acid denaturation and a simplified purification procedure resulting therefrom.

    PubMed

    Pellegrini, A; Hägeli, G; von Fellenberg, R

    1986-11-21

    Addition of perchloric acid (6.4% w/v final concentration) to horse alpha 1-proteinase inhibitor or to horse plasma neither precipitated nor inactivated alpha 1-proteinase inhibitor. None of the isoinhibitors of alpha 1-proteinase inhibitor was altered by dilute perchloric acid. This unexpected behavior led to a simplified procedure for the purification of horse alpha 1-proteinase inhibitor, consisting of removal of the bulk of plasma proteins, by perchloric acid precipitation and by gel filtration on Sephadex G-75 and G-200. The resulting preparations of alpha 1-proteinase inhibitor were immunogenically pure. The simplified purification procedure permitted the immunochemical comparison of the isoinhibitors of alpha 1-proteinase inhibitor, which proved to be immunologically identical. PMID:3022814

  9. A dual inhibitor of cyclooxygenase and 5-lipoxygenase protects against kainic acid-induced brain injury.

    PubMed

    Minutoli, Letteria; Marini, Herbert; Rinaldi, Mariagrazia; Bitto, Alessandra; Irrera, Natasha; Pizzino, Gabriele; Pallio, Giovanni; Calò, Margherita; Adamo, Elena Bianca; Trichilo, Vincenzo; Interdonato, Monica; Galfo, Federica; Squadrito, Francesco; Altavilla, Domenica

    2015-06-01

    Systemic administration of kainic acid causes inflammation and apoptosis in the brain, resulting in neuronal loss. Dual cyclooxygenase/5-lipoxygenase (COX/5-LOX) inhibitors could represent a possible neuroprotective approach in preventing glutamate excitotoxicity. Consequently, we investigated the effects of a dual inhibitor of COX/5-LOX following intraperitoneal administration of kainic acid (KA, 10 mg/kg) in rats. Animals were randomized to receive either the dual inhibitor of COX/5-LOX (flavocoxid, 20 mg/kg i.p.) or its vehicle (1 ml/kg i.p.) 30 min after KA administration. Sham brain injury rats were used as controls. We evaluated protein expression of phosphorylated extracellular signal-regulated kinase (p-ERK1/2) and tumor necrosis factor alpha (TNF-α) as well as levels of malondialdehyde (MDA), prostaglandin E2 (PGE2) and leukotriene B4 (LTB4) in the hippocampus. Animals were also observed for monitoring behavioral changes according to Racine Scale. Finally, histological analysis and brain edema evaluation were carried out. Treatment with the dual inhibitor of COX/5-LOX decreased protein expression of p-ERK1/2 and TNF-α in hippocampus, markedly reduced MDA, LTB4 and PGE2 hippocampal levels, and also ameliorated brain edema. Histological analysis showed a reduction in cell damage in rats treated with the dual inhibitor of COX/5-LOX, particularly in hippocampal subregion CA3c. Moreover, flavocoxid significantly improved behavioral signs following kainic acid administration. Our results suggest that dual inhibition of COX/5-LOX by flavocoxid has neuroprotective effects during kainic acid-induced excitotoxicity. PMID:25893744

  10. ALLYLISOPROPYLACETAMIDE INDUCES RAT HEPATIC ORNITHINE DECARBOXYLASE

    EPA Science Inventory

    In rat liver, allylisopropylacetamide (AIA) treatment strongly induced (25-fold) the activity of rat hepatic ornithine decarboxylase (ODC). y either the oral or the subcutaneous routes, AIA produced a long-lasting induction (30 to 4O hours) of hepatic ODC activity. hree analogs o...

  11. Formation of 10-Formylfolic Acid, a Potent Inhibitor of Dihydrofolate Reductase, in Rat Liver Slices Incubated with Folic Acid

    PubMed Central

    d'Urso-Scott, M.; Uhoch, J.; Bertino, J. R.

    1974-01-01

    During investigation of folate polyglutamate biosynthesis in rat liver slices utilizing [2-14C]folic acid, a folate compound that behaved like a polyglutamate form in the Sephadex G-15 gel filtration system was found to accumulate. Subsequent chromatographic, spectral, chemical, and enzymic studies have indicated that the compound formed in liver slices incubated with [14C]folic acid with and without methotrexate was 10-formyl folate. This folate is of interest in that it is the most potent natural inhibitor of dihydrofolate reductase known and may be capable of serving a regulatory function within the cell. PMID:4527808

  12. Identification of ellagic acid as potent inhibitor of protein kinase CK2: a successful example of a virtual screening application.

    PubMed

    Cozza, Giorgio; Bonvini, Paolo; Zorzi, Elisa; Poletto, Giorgia; Pagano, Mario A; Sarno, Stefania; Donella-Deana, Arianna; Zagotto, Giuseppe; Rosolen, Angelo; Pinna, Lorenzo A; Meggio, Flavio; Moro, Stefano

    2006-04-20

    Casein kinase 2 (CK2) is a ubiquitous, essential, and highly pleiotropic protein kinase whose abnormally high constitutive activity is suspected to underlie its pathogenic potential in neoplasia and other diseases. Using a virtual screening approach, we have identified the ellagic acid, a naturally occurring tannic acid derivative, as a novel potent CK2 inhibitor. At present, ellagic acid represents the most potent known CK2 inhibitor (K(i) = 20 nM). PMID:16610779

  13. Discovery, biosynthesis, and mechanism of action of the zaragozic acids: potent inhibitors of squalene synthase.

    PubMed

    Bergstrom, J D; Dufresne, C; Bills, G F; Nallin-Omstead, M; Byrne, K

    1995-01-01

    The zaragozic acids (ZAs), a family of fungal metabolites containing a novel 4,6,7-trihydroxy-2,8-dioxobicyclo[3.2.1]octane-3,4,5-tricarboxylic acid core, were discovered independently by two separate groups screening natural product sources to discover inhibitors of squalene synthase. This family of compounds all contain the same core but differ in their 1-alkyl and their 6-acyl side chains. Production of the ZAs is distributed over an extensive taxonomic range of Ascomycotina or their anamorphic states. The zaragozic acids are very potent inhibitors of squalene synthase that inhibit cholesterol synthesis and lower plasma cholesterol levels in primates. They also inhibit fungal ergosterol synthesis and are potent fungicidal compounds. The biosynthesis of the zaragozic acids appears to proceed through alkyl citrate intermediates and new members of the family have been produced through directed biosynthesis. These potent natural product based inhibitors of squalene synthase have potential to be developed either as cholesterol lowering agents and/or as antifungal agents. PMID:8561474

  14. Antitumor effects of tyropeptin-boronic acid derivatives: New proteasome inhibitors

    PubMed Central

    Momose, Isao; Abe, Hikaru; Watanabe, Takumi; Ohba, Shun-ichi; Yamazaki, Kanami; Dan, Shingo; Yamori, Takao; Masuda, Tohru; Nomoto, Akio

    2014-01-01

    The proteasome degrades numerous regulatory proteins that are critical for tumor growth. Thus, proteasome inhibitors are promising antitumor agents. New proteasome inhibitors, such as tyropeptins and tyropeptin-boronic acid derivatives, have a potent inhibitory activity. Here we report the antitumor effects of two new tyropeptin-boronic acid derivatives, AS-06 and AS-29. AS-06 and AS-29 significantly suppress the degradation of the proteasome-sensitive fluorescent proteins in HEK293PS cells, and induce the accumulation of ubiquitinated proteins in human multiple myeloma cells. We show that these derivatives also suppress the degradation of the NF-κB inhibitor IκB-α and the nuclear translocation of NF-κB p65 in multiple myeloma cells, resulting in the inhibition of NF-κB activation. Furthermore, we demonstrate that AS-06 and AS-29 induce apoptosis through the caspase-8 and caspase-9 cascades. In a xenograft mouse model, i.v. administration of tyropeptin-boronic acid derivatives inhibits proteasome in tumors and clearly suppresses tumor growth in mice bearing human multiple myeloma. Our results indicate that tyropeptin-boronic acid derivatives could be lead therapeutic agents against human multiple myeloma. PMID:25251038

  15. N-Benzyl-indolo carboxylic acids: Design and synthesis of potent and selective adipocyte fatty-acid binding protein (A-FABP) inhibitors.

    PubMed

    Barf, Tjeerd; Lehmann, Fredrik; Hammer, Kristin; Haile, Saba; Axen, Eva; Medina, Carmen; Uppenberg, Jonas; Svensson, Stefan; Rondahl, Lena; Lundbäck, Thomas

    2009-03-15

    Small molecule inhibitors of adipocyte fatty-acid binding protein (A-FABP) have gained renewed interest following the recent publication of pharmacologically beneficial effects of such inhibitors. Despite the potential utility of selective A-FABP inhibitors within the fields of metabolic disease, inflammation and atherosclerosis, there are few examples of useful A-FABP inhibitors in the public domain. Herein, we describe the optimization of N-benzyl-tetrahydrocarbazole derivatives through the use of co-crystal structure guided medicinal chemistry efforts. This led to the identification of a potent and selective class of A-FABP inhibitors as illustrated by N-benzyl-hexahydrocyclohepta[b]indole 30. PMID:19217286

  16. Synthesis of 4-substituted nipecotic acid derivatives and their evaluation as potential GABA uptake inhibitors.

    PubMed

    Hellenbrand, Tim; Höfner, Georg; Wein, Thomas; Wanner, Klaus T

    2016-05-01

    In this study, we disclose the design and synthesis of novel 4-susbtituted nipecotic acid derivatives as inhibitors of the GABA transporter mGAT1. Based on molecular modeling studies the compounds are assumed to adopt a binding pose similar to that of the potent mGAT1 inhibitor nipecotic acid. As substitution in 4-position should not cause an energetically unfavorable orientation of nipecotic acid as it is the case for N-substituted derivatives this is expected to lead to highly potent binders. For the synthesis of novel 4-substituted nipecotic acid derivatives a linear synthetic strategy was employed. As a key step, palladium catalyzed cross coupling reactions were used to attach the required biaryl moieties to the ω-position of the alkenyl- or alkynyl spacers of varying length in the 4-position of the nipecotic acid scaffold. The resulting amino acids were characterized with respect to their binding affinities and inhibitory potencies at mGAT1. Though the biological activities found were generally insignificant to poor, two compounds, one of which possesses a reasonable binding affinity for mGAT1, rac-57, the other a notable inhibitory potency at mGAT4, rac-84, both displaying a slight subtype selectivity for the individual transporters, could be identified. PMID:27039250

  17. Lichen secondary metabolite evernic acid as potential quorum sensing inhibitor against Pseudomonas aeruginosa.

    PubMed

    Gökalsın, Barış; Sesal, Nüzhet Cenk

    2016-09-01

    Cystic Fibrosis is a genetic disease and it affects the respiratory and digestive systems. Pseudomonas aeruginosa infections in Cystic Fibrosis are presented as the main cause for high mortality and morbidity rates. Pseudomonas aeruginosa populations can regulate their virulence gene expressions via the bacterial communication system: quorum sensing. Inhibition of quorum sensing by employing quorum sensing inhibitors can leave the bacteria vulnerable. Therefore, determining natural sources to obtain potential quorum sensing inhibitors is essential. Lichens have ethnobotanical value for their medicinal properties and it is possible that their secondary metabolites have quorum sensing inhibitor properties. This study aims to investigate an alternative treatment approach by utilizing lichen secondary metabolite evernic acid to reduce the expressions of Pseudomonas aeruginosa virulence factors by inhibiting quorum sensing. For this purpose, fluorescent monitor strains were utilized for quorum sensing inhibitor screens and quantitative reverse-transcriptase PCR analyses were conducted for comparison. Results indicate that evernic acid is capable of inhibiting Pseudomonas aeruginosa quorum sensing systems. PMID:27465850

  18. HDAC inhibitor valproic acid upregulates CAR in vitro and in vivo

    PubMed Central

    Segura-Pacheco, Blanca; Avalos, Berenice; Rangel, Edgar; Velazquez, Dora; Cabrera, Gustavo

    2007-01-01

    Background The presence of CAR in diverse tumor types is heterogeneous with implications in tumor transduction efficiency in the context of adenoviral mediated cancer gene therapy. Preliminary studies suggest that CAR transcriptional regulation is modulated through histone acetylation and not through promoter methylation. Furthermore, it has been documented that the pharmacological induction of CAR using histone deacetylase inhibitor (iHDAC) compounds is a viable strategy to enhance adenoviral mediated gene delivery to cancer cells in vitro. The incorporation of HDAC drugs into the overall scheme in adenoviral based cancer gene therapy clinical trials seems rational. However, reports using compounds with iHDAC properties utilized routinely in the clinic are pending. Valproic acid, a short chained fatty acid extensively used in the clinic for the treatment of epilepsy and bipolar disorder has been recently described as an effective HDAC inhibitor at therapeutic concentrations. Methods We studied the effect of valproic acid on histone H3 and H4 acetylation, CAR mRNA upregulation was studied using semiquantitative PCR and adenoviral transduction on HeLa cervical cancer cells, on MCF-7 breast cancer cells, on T24 transitional cell carcinoma of the bladder cells. CAR mRNA was studied using semiquantitative PCR on tumor tissue extracted from patients diagnosed with cervical cancer treated with valproic acid. Results CAR upregulation through HDAC inhibition was observed in the three cancer cell lines with enhancement of adenoviral transduction. CAR upregulation was also observed in tumor samples obtained from patients with cervical cancer treated with therapeutic doses of valproic acid. These results support the addition of the HDAC inhibitor valproic acid to adenoviral mediated cancer gene therapy clinical trials to enhance adenoviral mediated gene delivery to the tumor cells. PMID:17892546

  19. Products of the Black Sea alga Phyllophora nervosa as corrosion inhibitor for steel in acids

    SciTech Connect

    Popelyukh, G.M.; Andrianov, A.M.; Burtnenko, L.M.; Gazha, P.A.; Talavira, L.I.

    1986-05-01

    The authors have investigated the inhibiting properties of the processing products of the Black Sea red seaweed Phyllophora nervosa on specimens of steel St3 in phosphoric and hydrochloric acids of various concentrations at temperatures in the range from 30 to 95 /sup 0/C. They have studied how the concentrations of urotropin, sodium chloride, and Fe/sup 3 +/ ions influence the protective properties of the seaweed inhibitor. They have made preliminary investigations of the mechanisms of the protective action.

  20. The gyrase inhibitor albicidin consists of p-aminobenzoic acids and cyanoalanine.

    PubMed

    Cociancich, Stéphane; Pesic, Alexander; Petras, Daniel; Uhlmann, Stefanie; Kretz, Julian; Schubert, Vivien; Vieweg, Laura; Duplan, Sandrine; Marguerettaz, Mélanie; Noëll, Julie; Pieretti, Isabelle; Hügelland, Manuela; Kemper, Sebastian; Mainz, Andi; Rott, Philippe; Royer, Monique; Süssmuth, Roderich D

    2015-03-01

    Albicidin is a potent DNA gyrase inhibitor produced by the sugarcane pathogenic bacterium Xanthomonas albilineans. Here we report the elucidation of the hitherto unknown structure of albicidin, revealing a unique polyaromatic oligopeptide mainly composed of p-aminobenzoic acids. In vitro studies provide further insights into the biosynthetic machinery of albicidin. These findings will enable structural investigations on the inhibition mechanism of albicidin and its assessment as a highly effective antibacterial drug. PMID:25599532

  1. How polyamine synthesis inhibitors and cinnamic acid affect tropane alkaloid production.

    PubMed

    Marconi, Patricia L; Alvarez, María A; Pitta-Alvarez, Sandra I

    2007-01-01

    Hairy roots of Brugmansia candida produce the tropane alkaloids scopolamine and hyoscyamine. In an attempt to divert the carbon flux from competing pathways and thus enhance productivity, the polyamine biosynthesis inhibitors cyclohexylamine (CHA) and methylglyoxal-bis-guanylhydrazone (MGBG) and the phenylalanine-ammonia-lyase inhibitor cinnamic acid were used. CHA decreased the specific productivity of both alkaloids but increased significantly the release of scopolamine (approx 500%) when it was added in the mid-exponential phase. However, when CHA was added for only 48 h during the exponential phase, the specific productivity of both alkaloids increased (approx 200%), favoring scopolamine. Treatment with MGBG was detrimental to growth but promoted release into the medium of both alkaloids. However, when it was added for 48 h during the exponential phase, MGBG increased the specific productivity (approx 200%) and release (250- 1800%) of both alkaloids. Cinnamic acid alone also favored release but not specific productivity. When a combination of CHA or MGBG with cinnamic acid was used, the results obtained were approximately the same as with each polyamine biosynthesis inhibitor alone, although to a lesser extent. Regarding root morphology, CHA inhibited growth of primary roots and ramification. However, it had a positive effect on elongation of lateral roots. PMID:17416978

  2. Corrosion damage of the surface of high-speed tool steel in acid-inhibitor pickling

    SciTech Connect

    Mindyuk, A.K.; Sholok, V.I.; Shvets, V.V. Gural', V.M.

    1988-01-01

    Profilograms were recorded of the surface of 20-mm-diameter 1.5-mm-thick specimens prepared from hardened and tempered R6M5 high-speed tool steel (62 HRC) and also of similar specimens subjected to the action of pure hydrochloric acid etching solution and of the same solutions with additions of KhOSP-10, KhOSP-10D, and urotropin inhibitors at 30, 60, and 90/sup 0/C for 4.0, 2.0, and 0.5 h, respectively. The analysis of corrosion damage and determination of the surface finish of the steel made it possible to develop the optimum method of acid-inhibitor pickling specifying the addition to the acid of 1.5 g/liter KhOSP-10 inhibitor and a temperature of 30/sup 0/C. This suppressed the corrosion rate, hydrogen impregnation and embrittlement, decarburization of the steel, and sensitivity to crack formation, and reduced the number of scrapped parts.

  3. Inhibition of human ornithine decarboxylase activity by enantiomers of difluoromethylornithine.

    PubMed Central

    Qu, Ning; Ignatenko, Natalia A; Yamauchi, Phillip; Stringer, David E; Levenson, Corey; Shannon, Patrick; Perrin, Scott; Gerner, Eugene W

    2003-01-01

    Racemic difluoromethylornithine (D/L-DFMO) is an inhibitor of ODC (ornithine decarboxylase), the first enzyme in eukaryotic polyamine biosynthesis. D/L-DFMO is an effective anti-parasitic agent and inhibitor of mammalian cell growth and development. Purified human ODC-catalysed ornithine decarboxylation is highly stereospecific. However, both DFMO enantiomers suppressed ODC activity in a time- and concentration-dependent manner. ODC activity failed to recover after treatment with either L- or D-DFMO and dialysis to remove free inhibitor. The inhibitor dissociation constant (K(D)) values for the formation of enzyme-inhibitor complexes were 28.3+/-3.4, 1.3+/-0.3 and 2.2+/-0.4 microM respectively for D-, L- and D/L-DFMO. The differences in these K(D) values were statistically significant ( P <0.05). The inhibitor inactivation constants (K(inact)) for the irreversible step were 0.25+/-0.03, 0.15+/-0.03 and 0.15+/-0.03 min(-1) respectively for D-, L- and D/L-DFMO. These latter values were not statistically significantly different ( P >0.1). D-DFMO was a more potent inhibitor (IC50 approximately 7.5 microM) when compared with D-ornithine (IC50 approximately 1.5 mM) of ODC-catalysed L-ornithine decarboxylation. Treatment of human colon tumour-derived HCT116 cells with either L- or D-DFMO decreased the cellular polyamine contents in a concentration-dependent manner. These results show that both enantiomers of DFMO irreversibly inactivate ODC and suggest that this inactivation occurs by a common mechanism. Both enantiomers form enzyme-inhibitor complexes with ODC, but the probability of formation of these complexes is 20 times greater for L-DFMO when compared with D-DFMO. The rate of the irreversible reaction in ODC inactivation is similar for the L- and D-enantiomer. This unexpected similarity between DFMO enantiomers, in contrast with the high degree of stereospecificity of the substrate ornithine, appears to be due to the alpha-substituent of the inhibitor. The D

  4. The ornithine decarboxylase gene of Caenorhabditis elegans: Cloning, mapping and mutagenesis

    SciTech Connect

    Macrae, M.; Coffino, P.; Plasterk, R.H.A.

    1995-06-01

    The gene (odc-1) encoding ornithine decarboxylase, a key enzyme in polyamine biosynthesis, was cloned and characterized. Two introns interrupt the coding sequence of the gene. The deduced protein contains 442 amino acids and is homologous to ornithine decarboxylases of other eukaryotic species. In vitro translation of a transcript of the cDNA yielded an enzymatically active product. The mRNA is 1.5 kb in size and is formed by trans-splicing to SL1, a common 5{prime} RNA segment. odc-1 maps to the middle of LG V, between dpy-11 and unc-42 and near a breakpoint of the nDf32 deficiency strain. Enzymatic activity is low in starved 1 (L1) larva and, after feeding, rises progressively as the worms develop. Targeted gene disruption was used to create a null allele. Homozygous mutants are normally viable and show no apparent defects, with the exception of a somewhat reduced brood size. In vitro assays for ornithine decarboxylase activity, however, show no detectable enzymatic activity, suggesting that ornithine decarboxylase is dispensible for nematode growth in the laboratory. 37 refs., 6 figs., 1 tab.

  5. Plasmin inhibitors with hydrophobic amino acid-based linker between hydantoin moiety and benzimidazole scaffold enhance inhibitory activity.

    PubMed

    Teno, Naoki; Gohda, Keigo; Yamashita, Yukiko; Otsubo, Tadamune; Yamaguchi, Masafumi; Wanaka, Keiko; Tsuda, Yuko

    2016-05-01

    In this letter we report the design and synthesis of a series of plasmin inhibitors, which share the amino acid-based linker with limited free rotation between the hydantoin moiety and the benzimidazole scaffold. Our studies led to potent plasmin inhibitors and yielded important new insights into their structure-activity relationship for binding to the active site of plasmin. PMID:27009905

  6. Suppression of asymmetric acid efflux and gravitropism in maize roots treated with auxin transport inhibitors of sodium orthovanadate

    NASA Technical Reports Server (NTRS)

    Mulkey, T. J.; Evans, M. L.

    1982-01-01

    In gravitropically stimulated roots of maize (Zea mays L., hybrid WF9 x 38MS), there is more acid efflux on the rapidly growing upper side than on the slowly growing lower side. In light of the Cholodny/Went hypothesis of gravitropism which states that gravitropic curvature results from lateral redistribution of auxin, the effects of auxin transport inhibitors on the development of acid efflux asymmetry and curvature in gravistimulated roots were examined. All the transport inhibitors tested prevented both gravitropism and the development of asymmetric acid efflux in gravistimulated roots. The results indicate that auxin redistribution may cause the asymmetry of acid efflux, a finding consistent with the Cholodny/Went hypothesis of gravitropism. As further evidence that auxin-induced acid efflux asymmetry may mediate gravitropic curvature, sodium orthovanadate, an inhibitor of auxin-induced H+ efflux was found to prevent both gravitropism and the development of asymmetric acid efflux in gravistimulated roots.

  7. Discovery of novel, non-acidic mPGES-1 inhibitors by virtual screening with a multistep protocol

    PubMed Central

    Noha, Stefan M.; Fischer, Katrin; Koeberle, Andreas; Garscha, Ulrike; Werz, Oliver; Schuster, Daniela

    2015-01-01

    Microsomal prostaglandin E2 synthase-1 (mPGES-1) inhibitors are considered as potential therapeutic agents for the treatment of inflammatory pain and certain types of cancer. So far, several series of acidic as well as non-acidic inhibitors of mPGES-1 have been discovered. Acidic inhibitors, however, may have issues, such as loss of potency in human whole blood and in vivo, stressing the importance of the design and identification of novel, non-acidic chemical scaffolds of mPGES-1 inhibitors. Using a multistep virtual screening protocol, the Vitas-M compound library (∼1.3 million entries) was filtered and 16 predicted compounds were experimentally evaluated in a biological assay in vitro. This approach yielded two molecules active in the low micromolar range (IC50 values: 4.5 and 3.8 μM, respectively). PMID:26088337

  8. Functional Roles of the Dimer-Interface Residues in Human Ornithine Decarboxylase

    PubMed Central

    Lee, Chien-Yun; Liu, Yi-Liang; Lin, Chih-Li; Liu, Guang-Yaw; Hung, Hui-Chih

    2014-01-01

    Ornithine decarboxylase (ODC) catalyzes the decarboxylation of ornithine to putrescine and is the rate-limiting enzyme in the polyamine biosynthesis pathway. ODC is a dimeric enzyme, and the active sites of this enzyme reside at the dimer interface. Once the enzyme dissociates, the enzyme activity is lost. In this paper, we investigated the roles of amino acid residues at the dimer interface regarding the dimerization, protein stability and/or enzyme activity of ODC. A multiple sequence alignment of ODC and its homologous protein antizyme inhibitor revealed that 5 of 9 residues (residues 165, 277, 331, 332 and 389) are divergent, whereas 4 (134, 169, 294 and 322) are conserved. Analytical ultracentrifugation analysis suggested that some dimer-interface amino acid residues contribute to formation of the dimer of ODC and that this dimerization results from the cooperativity of these interface residues. The quaternary structure of the sextuple mutant Y331S/Y389D/R277S/D332E/V322D/D134A was changed to a monomer rather than a dimer, and the Kd value of the mutant was 52.8 µM, which is over 500-fold greater than that of the wild-type ODC (ODC_WT). In addition, most interface mutants showed low but detectable or negligible enzyme activity. Therefore, the protein stability of these interface mutants was measured by differential scanning calorimetry. These results indicate that these dimer-interface residues are important for dimer formation and, as a consequence, are critical for enzyme catalysis. PMID:25140796

  9. Structures of Bacterial Biosynthetic Arginine Decarboxylases

    SciTech Connect

    F Forouhar; S Lew; J Seetharaman; R Xiao; T Acton; G Montelione; L Tong

    2011-12-31

    Biosynthetic arginine decarboxylase (ADC; also known as SpeA) plays an important role in the biosynthesis of polyamines from arginine in bacteria and plants. SpeA is a pyridoxal-5'-phosphate (PLP)-dependent enzyme and shares weak sequence homology with several other PLP-dependent decarboxylases. Here, the crystal structure of PLP-bound SpeA from Campylobacter jejuni is reported at 3.0 {angstrom} resolution and that of Escherichia coli SpeA in complex with a sulfate ion is reported at 3.1 {angstrom} resolution. The structure of the SpeA monomer contains two large domains, an N-terminal TIM-barrel domain followed by a {beta}-sandwich domain, as well as two smaller helical domains. The TIM-barrel and {beta}-sandwich domains share structural homology with several other PLP-dependent decarboxylases, even though the sequence conservation among these enzymes is less than 25%. A similar tetramer is observed for both C. jejuni and E. coli SpeA, composed of two dimers of tightly associated monomers. The active site of SpeA is located at the interface of this dimer and is formed by residues from the TIM-barrel domain of one monomer and a highly conserved loop in the {beta}-sandwich domain of the other monomer. The PLP cofactor is recognized by hydrogen-bonding, {pi}-stacking and van der Waals interactions.

  10. Chemical Genetics Uncovers Novel Inhibitors of Lignification, Including p-Iodobenzoic Acid Targeting CINNAMATE-4-HYDROXYLASE.

    PubMed

    Van de Wouwer, Dorien; Vanholme, Ruben; Decou, Raphaël; Goeminne, Geert; Audenaert, Dominique; Nguyen, Long; Höfer, René; Pesquet, Edouard; Vanholme, Bartel; Boerjan, Wout

    2016-09-01

    Plant secondary-thickened cell walls are characterized by the presence of lignin, a recalcitrant and hydrophobic polymer that provides mechanical strength and ensures long-distance water transport. Exactly the recalcitrance and hydrophobicity of lignin put a burden on the industrial processing efficiency of lignocellulosic biomass. Both forward and reverse genetic strategies have been used intensively to unravel the molecular mechanism of lignin deposition. As an alternative strategy, we introduce here a forward chemical genetic approach to find candidate inhibitors of lignification. A high-throughput assay to assess lignification in Arabidopsis (Arabidopsis thaliana) seedlings was developed and used to screen a 10-k library of structurally diverse, synthetic molecules. Of the 73 compounds that reduced lignin deposition, 39 that had a major impact were retained and classified into five clusters based on the shift they induced in the phenolic profile of Arabidopsis seedlings. One representative compound of each cluster was selected for further lignin-specific assays, leading to the identification of an aromatic compound that is processed in the plant into two fragments, both having inhibitory activity against lignification. One fragment, p-iodobenzoic acid, was further characterized as a new inhibitor of CINNAMATE 4-HYDROXYLASE, a key enzyme of the phenylpropanoid pathway synthesizing the building blocks of the lignin polymer. As such, we provide proof of concept of this chemical biology approach to screen for inhibitors of lignification and present a broad array of putative inhibitors of lignin deposition for further characterization. PMID:27485881

  11. Effect of carbonyl inhibitors and their H₂O₂ detoxification on lactic acid fermentation.

    PubMed

    Li, Jing; Zhu, Caiqing; Tu, Maobing; Han, Pingping; Wu, Yonnie

    2015-04-01

    Biomass degradation compounds significantly inhibit biochemical conversion of biomass prehydrolysates to biofuels and chemicals, such as lactic acid. To characterize the structure-activity relationship of carbonyl inhibition on lactic acid fermentation, we examined effects of eight carbonyl compounds (furfural, 5-hydroxymethyl furfural, vanillin, syringaldehyde, 4-hydroxybenzaldehyde, phthalaldehyde, benzoic acid, and pyrogallol aldehyde) and creosol on lactic acid production by Lactobacillus delbrueckii. Pyrogallol aldehyde reduced the cell growth rate by 35 % at 1.0 mM and inhibited lactic acid production completely at 2.0 mM. By correlating the molecular descriptors to the inhibition constants in lactic acid fermentation, we found a good relationship between the hydrophobicity (Log P) of aldehydes and their inhibition constants in fermentation. The inhibitory effect of carbonyl inhibitors appeared to correlate with their thiol reactivity as well. In addition, we found that H2O2 detoxified pyrogallol aldehyde and phthalaldehyde inhibitory activity. H2O2 detoxification was applied to real biomass prehydrolysates in lactic acid fermentation. PMID:25666370

  12. Select microtubule inhibitors increase lysosome acidity and promote lysosomal disruption in acute myeloid leukemia (AML) cells.

    PubMed

    Bernard, Dannie; Gebbia, Marinella; Prabha, Swayam; Gronda, Marcela; MacLean, Neil; Wang, Xiaoming; Hurren, Rose; Sukhai, Mahadeo A; Cho, Eunice E; Manolson, Morris F; Datti, Alessandro; Wrana, Jeffrey; Minden, Mark D; Al-Awar, Rima; Aman, Ahmed; Nislow, Corey; Giaever, Guri; Schimmer, Aaron D

    2015-07-01

    To identify new biological vulnerabilities in acute myeloid leukemia, we screened a library of natural products for compounds cytotoxic to TEX leukemia cells. This screen identified the novel small molecule Deoxysappanone B 7,4' dimethyl ether (Deox B 7,4), which possessed nanomolar anti-leukemic activity. To determine the anti-leukemic mechanism of action of Deox B 7,4, we conducted a genome-wide screen in Saccharomyces cerevisiae and identified enrichment of genes related to mitotic cell cycle as well as vacuolar acidification, therefore pointing to microtubules and vacuolar (V)-ATPase as potential drug targets. Further investigations into the mechanisms of action of Deox B 7,4 and a related analogue revealed that these compounds were reversible microtubule inhibitors that bound near the colchicine site. In addition, Deox B 7,4 and its analogue increased lysosomal V-ATPase activity and lysosome acidity. The effects on microtubules and lysosomes were functionally important for the anti-leukemic effects of these drugs. The lysosomal effects were characteristic of select microtubule inhibitors as only the Deox compounds and nocodazole, but not colchicine, vinca alkaloids or paclitaxel, altered lysosome acidity and induced lysosomal disruption. Thus, our data highlight a new mechanism of action of select microtubule inhibitors on lysosomal function. PMID:25832785

  13. N-substituted aminomethanephosphonic and aminomethane-P-methylphosphinic acids as inhibitors of ureases.

    PubMed

    Berlicki, Lukasz; Bochno, Marta; Grabowiecka, Agnieszka; Białas, Arkadiusz; Kosikowska, Paulina; Kafarski, Paweł

    2012-05-01

    Small unextended molecules based on the diamidophosphate structure with a covalent carbon-to-phosphorus bond to improve hydrolytic stability were developed as a novel group of inhibitors to control microbial urea decomposition. Applying a structure-based inhibitor design approach using available crystal structures of bacterial urease, N-substituted derivatives of aminomethylphosphonic and P-methyl-aminomethylphosphinic acids were designed and synthesized. In inhibition studies using urease from Bacillus pasteurii and Canavalia ensiformis, the N,N-dimethyl derivatives of both lead structures were most effective with dissociation constants in the low micromolar range (Ki=13±0.8 and 0.62±0.09 μM, respectively). Whole-cell studies on a ureolytic strain of Proteus mirabilis showed the high efficiency of N,N-dimethyl and N-methyl derivatives of aminomethane-P-methylphosphinic acids for urease inhibition in pathogenic bacteria. The high hydrolytic stability of selected inhibitors was confirmed over a period of 30 days using NMR technique. PMID:21559954

  14. Search for novel histone deacetylase inhibitors. Part II: design and synthesis of novel isoferulic acid derivatives.

    PubMed

    Lu, Wen; Wang, Fang; Zhang, Tao; Dong, Jinyun; Gao, Hongping; Su, Ping; Shi, Yaling; Zhang, Jie

    2014-05-01

    Previously, we described the discovery of potent ferulic acid-based histone deacetylase inhibitors (HDACIs) with halogeno-acetanilide as novel surface recognition moiety (SRM). In order to improve the affinity and activity of these HDACIs, twenty seven isoferulic acid derivatives were described herein. The majority of title compounds displayed potent HDAC inhibitory activity. In particular, IF5 and IF6 exhibited significant enzymatic inhibitory activities, with IC50 values of 0.73 ± 0.08 and 0.57 ± 0.16 μM, respectively. Furthermore, these compounds showed moderate antiproliferative activity against human cancer cells. Especially, IF6 displayed promising profile as an antitumor candidate with IC50 value of 3.91 ± 0.97 μM against HeLa cells. The results indicated that these isoferulic acid derivatives could serve as promising lead compounds for further optimization. PMID:24702857

  15. Development of novel ferulic acid derivatives as potent histone deacetylase inhibitors.

    PubMed

    Wang, Fang; Lu, Wen; Zhang, Tao; Dong, Jinyun; Gao, Hongping; Li, Pengfei; Wang, Sicen; Zhang, Jie

    2013-11-15

    Histone deacetylase inhibitors (HDACIs) offer a promising strategy for cancer therapy. The discovery of potent ferulic acid-based HDACIs with hydroxamic acid or 2-aminobenzamide group as zinc binding group was reported. The halogeno-acetanilide was introduced as novel surface recognition moiety (SRM). The majority of title compounds displayed potent HDAC inhibitory activity. In particular, FA6 and FA16 exhibited significant enzymatic inhibitory activities, with IC50 values of 3.94 and 2.82 μM, respectively. Furthermore, these compounds showed moderate antiproliferative activity against a panel of human cancer cells. FA17 displayed promising profile as an antitumor candidate. The results indicated that these ferulic acid derivatives could serve as promising lead compounds for further optimization. PMID:24095016

  16. Inhibitory activity of Filipendula ulmaria constituents on recombinant human histidine decarboxylase.

    PubMed

    Nitta, Yoko; Kikuzaki, Hiroe; Azuma, Toshiaki; Ye, Yuan; Sakaue, Motoyoshi; Higuchi, Yoshiki; Komori, Hirohumi; Ueno, Hiroshi

    2013-06-01

    Histidine decarboxylase (HDC) catalyses the formation of histamine, a bioactive amine. Agents that control HDC activity are beneficial for treating histamine-mediated symptoms, such as allergies and stomach ulceration. We searched for inhibitors of HDC from the ethyl acetate extract of the petal of Filipendula ulmaria, also called meadowsweet. Rugosin D, rugosin A, rugosin A methyl ester (a novel compound), and tellimagrandin II were the main components; these 4 ellagitannins exhibited a non-competitive type of inhibition, with K(i) values of approximately 0.35-1 μM. These K(i) values are nearly equal to that of histidine methyl ester (K(i)=0.46 μM), an existing substrate analogue inhibitor. Our results show that food products contain potent HDC inhibitors and that these active food constituents might be useful for designing clinically available HDC inhibitors. PMID:23411280

  17. Discovery of arjunolic acid as a novel non-zinc binding carbonic anhydrase II inhibitor.

    PubMed

    Kalyanavenkataraman, Subhalakshmi; Nanjan, Pandurangan; Banerji, Asoke; Nair, Bipin G; Kumar, Geetha B

    2016-06-01

    Elevated levels of carbonic anhydrase II (CA II) have been shown to be associated with cardiac hypertrophy and heart failure. Although arjunolic acid (AA) has a diverse range of therapeutic applications including cardio-protection, there have been no reports on the effect of AA on CA II. The present study describes for the first time, the novel zinc independent inhibition of CA II by AA. The molecular docking studies of AA indicated that the hydroxyl group at C2 of the A-ring, which hydrogen bonds with the catalytic site residues (His64, Asn62 and Asn67), along with the gem-dimethyl group at C20 of the E-ring, greatly influences the inhibitory activity, independent of the catalytic zinc, unlike the inhibition observed with most CA II inhibitors. Among the triterpenoids tested viz. arjunolic acid, arjunic acid, asiatic acid, oleanolic acid and ursolic acid, AA was the most potent in inhibiting CA II in vitro with an IC50 of 9μM. It was interesting to note, that in spite of exhibiting very little differences in their structures, these triterpenoids exhibited vast differences in their inhibitory activities, with IC50 values ranging from 9μM to as high as 333μM. Furthermore, AA also inhibited the cytosolic activity of CA in H9c2 cardiomyocytes, as reflected by the decrease in acidification of the intracellular pH (pHi). The decreased acidification reduced the intracellular calcium levels, which further prevented the mitochondrial membrane depolarization. Thus, these studies provide a better understanding for establishing the novel molecular mechanism involved in CA II inhibition by the non-zinc binding inhibitor AA. PMID:27038848

  18. Potent inhibitors of HCV-NS3 protease derived from boronic acids

    SciTech Connect

    Venkatraman, Srikanth; Wu, Wanli; Prongay, Andrew; Girijavallabhan, Viyyoor; Njoroge, F. George

    2009-07-23

    Chronic hepatitis C infection is the leading causes for cirrhosis of the liver and hepatocellular carcinoma, leading to liver failure and liver transplantation. The etiological agent, HCV virus produces a single positive strand of RNA that is processed with the help of serine protease NS3 to produce mature virus. Inhibition of NS3 protease can be potentially used to develop effective drugs for HCV infections. Numerous efforts are now underway to develop potent inhibitors of HCV protease that contain ketoamides as serine traps. Herein we report the synthesis of a series of potent inhibitors that contain a boronic acid as a serine trap. The activity of these compounds were optimized to 200 pM. X-ray structure of compound 17 bound to NS3 protease is also discussed.

  19. Synthesis and characterization of phosphocitric acid, a potent inhibitor of hydroxylapatite crystal growth.

    PubMed

    Tew, W P; Mahle, C; Benavides, J; Howard, J E; Lehninger, A L

    1980-04-29

    Human urine and extracts of rat liver mitochondria contain apparently identical agents capable of inhibiting the precipitation or crystallization of calcium phosphate. Its general properties, as well as 1H NMR and mass spectra, have suggested that the agent is phosphocitric acid. This paper reports the synthesis of phosphocitric acid via the phosphorylation of triethyl citrate with o-phenylene phosphochloridate, hydrogenolysis of the product to yield triethyl phosphocitrate, hydrolytic removal of the blocking ethyl groups and also chromatographic purification. An enzymatic assay of phosphocitrate is described. Synthetic phosphocitrate was found to be an exceedingly potent inhibitor of the growth of hydroxylapatite seed crystals in a medium supersaturated with respect to Ca2+ and phosphate. Comparative assays showed phosphocitrate to be much more potent than the most active precipitation-crystallization inhibitors previously reported, which include pyrophosphate and ATP. 14C-Labeled phosphocitrate was bound very tightly to hydroxylapatite crystals. Such binding appeared to be essential for its inhibitory activity on crystal growth. Citrate added before but not after, phosphocitrate greatly enhanced the inhibitory potency of the latter. This enhancement effect was not given by other tricarboxylic acids. The monoethyl ester of phosphocitrate had no inhibitory effect on hydroxylapatite crystal growth. PMID:7378389

  20. Inhibition of Pig Phosphoenolpyruvate Carboxykinase Isoenzymes by 3-Mercaptopicolinic Acid and Novel Inhibitors.

    PubMed

    Hidalgo, Jorge; Latorre, Pedro; Carrodeguas, José Alberto; Velázquez-Campoy, Adrián; Sancho, Javier; López-Buesa, Pascual

    2016-01-01

    There exist two isoforms of cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C) in pig populations that differ in a single amino acid (Met139Leu). The isoenzymes have different kinetic properties, affecting more strongly the Km and Vmax of nucleotides. They are associated to different phenotypes modifying traits of considerable economic interest. In this work we use inhibitors of phosphoenolpyruvate carboxykinase activity to search for further differences between these isoenzymes. On the one hand we have used the well-known inhibitor 3-mercaptopicolinic acid. Its inhibition patterns were the same for both isoenzymes: a three-fold decrease of the Ki values for GTP in 139Met and 139Leu (273 and 873 μM, respectively). On the other hand, through screening of a chemical library we have found two novel compounds with inhibitory effects of a similar magnitude to that of 3-mercaptopicolinic acid but with less solubility and specificity. One of these novel compounds, (N'1-({5-[1-methyl-5-(trifluoromethyl)-1H-pyrazol-3-yl]-2-thienyl}methylidene)-2,4-dichlorobenzene-1-carbohydrazide), exhibited significantly different inhibitory effects on either isoenzyme: it enhanced threefold the apparent Km value for GTP in 139Met, whereas in 139Leu, it reduced it from 99 to 69 μM. The finding of those significant differences in the binding of GTP reinforces the hypothesis that the Met139Leu substitution affects strongly the nucleotide binding site of PEPCK-C. PMID:27391465

  1. Inhibition of Pig Phosphoenolpyruvate Carboxykinase Isoenzymes by 3-Mercaptopicolinic Acid and Novel Inhibitors

    PubMed Central

    Hidalgo, Jorge; Latorre, Pedro; Carrodeguas, José Alberto; Velázquez-Campoy, Adrián; Sancho, Javier; López-Buesa, Pascual

    2016-01-01

    There exist two isoforms of cytosolic phosphoenolpyruvate carboxykinase (PEPCK-C) in pig populations that differ in a single amino acid (Met139Leu). The isoenzymes have different kinetic properties, affecting more strongly the Km and Vmax of nucleotides. They are associated to different phenotypes modifying traits of considerable economic interest. In this work we use inhibitors of phosphoenolpyruvate carboxykinase activity to search for further differences between these isoenzymes. On the one hand we have used the well-known inhibitor 3-mercaptopicolinic acid. Its inhibition patterns were the same for both isoenzymes: a three-fold decrease of the Ki values for GTP in 139Met and 139Leu (273 and 873 μM, respectively). On the other hand, through screening of a chemical library we have found two novel compounds with inhibitory effects of a similar magnitude to that of 3-mercaptopicolinic acid but with less solubility and specificity. One of these novel compounds, (N'1-({5-[1-methyl-5-(trifluoromethyl)-1H-pyrazol-3-yl]-2-thienyl}methylidene)-2,4-dichlorobenzene-1-carbohydrazide), exhibited significantly different inhibitory effects on either isoenzyme: it enhanced threefold the apparent Km value for GTP in 139Met, whereas in 139Leu, it reduced it from 99 to 69 μM. The finding of those significant differences in the binding of GTP reinforces the hypothesis that the Met139Leu substitution affects strongly the nucleotide binding site of PEPCK-C. PMID:27391465

  2. Polyamine formation by arginine decarboxylase as a transducer of hormonal, environmental and stress stimuli in higher plants

    NASA Technical Reports Server (NTRS)

    Galston, A. W.; Flores, H. E.; Kaur-Sawhney, R.

    1982-01-01

    Recent evidence implicates polyamines including putrescine in the regulation of such diverse plant processes as cell division, embryogenesis and senescence. We find that the enzyme arginine decarboxylase, which controls the rate of putrescine formation in some plant systems, is activated by light acting through P(r) phytochrome as a receptor, by the plant hormone gibberellic acid, by osmotic shock and by other stress stimuli. We therefore propose arginine decarboxylase as a possible transducer of the various initially received tropistic stimuli in plants. The putrescine formed could act by affecting cytoskeletal components.

  3. C-3 benzoic acid derivatives of C-3 deoxybetulinic acid and deoxybetulin as HIV-1 maturation inhibitors.

    PubMed

    Liu, Zheng; Swidorski, Jacob J; Nowicka-Sans, Beata; Terry, Brian; Protack, Tricia; Lin, Zeyu; Samanta, Himadri; Zhang, Sharon; Li, Zhufang; Parker, Dawn D; Rahematpura, Sandhya; Jenkins, Susan; Beno, Brett R; Krystal, Mark; Meanwell, Nicholas A; Dicker, Ira B; Regueiro-Ren, Alicia

    2016-04-15

    A series of C-3 phenyl- and heterocycle-substituted derivatives of C-3 deoxybetulinic acid and C-3 deoxybetulin was designed and synthesized as HIV-1 maturation inhibitors (MIs) and evaluated for their antiviral activity and cytotoxicity in cell culture. A 4-subsituted benzoic acid moiety was identified as an advantageous replacement for the 3'3'-dimethylsuccinate moiety present in previously disclosed MIs that illuminates new aspects of the topography of the pharmacophore. The new analogs exhibit excellent in vitro antiviral activity against wild-type (wt) virus and a lower serum shift when compared with the prototypical HIV-1 MI bevirimat (1, BVM), the first MI to be evaluated in clinical studies. Compound 9a exhibits comparable cell culture potency toward wt virus as 1 (WT EC50=16nM for 9a compared to 10nM for 1). However, the potency of 9a is less affected by the presence of human serum, while the compound displays a similar pharmacokinetic profile in rats to 1. Hence 9a, the 4-benzoic acid derivative of deoxybetulinic acid, represents a new starting point from which to explore the design of a 2nd generation MI. PMID:26968652

  4. Benzimidazole as corrosion inhibitor for heat treated 6061 Al- SiCp composite in acetic acid

    NASA Astrophysics Data System (ADS)

    Chacko, Melby; Nayak, Jagannath

    2015-06-01

    6061 Al-SiCpcomposite was solutionizedat 350 °C for 30 minutes and water quenched. It was then underaged at 140 °C (T6 treatment). The aging behaviour of the composite was studied using Rockwell B hardness measurement. Corrosion behaviour of the underaged sample was studied in different concentrations of acetic acid and at different temperatures. Benzimidazole at different concentrations was used for the inhibition studies. Inhibition efficiency of benzimidazole was calculated for different experimental conditions. Thermodynamic parameters were found out which suggested benzimidazole is an efficient inhibitor and it adsorbed on to the surface of composite by mixed adsorption where chemisorption is predominant.

  5. Effect of acid-corrosion inhibitors on the pickling of scale from steels

    SciTech Connect

    Podobaev, N.I.

    1988-07-01

    This article examines features of the dissolution of scale and its component oxides in contact with steel in acids. It also looks at possible kinetic mechanisms of the dissolution of iron oxides, the effect of inhibitors and other additives on the dissolution of the metal and scale, and methods of measuring the dynamics of pickling. A distinction is made between high-temperature scale formed on plain-carbon and low-alloy steels above 570-800/degree/C and low-temperature scale formed below 570/degree/C.

  6. Reduced food intake and body weight in mice treated with fatty acid synthase inhibitors.

    PubMed

    Loftus, T M; Jaworsky, D E; Frehywot, G L; Townsend, C A; Ronnett, G V; Lane, M D; Kuhajda, F P

    2000-06-30

    With the escalation of obesity-related disease, there is great interest in defining the mechanisms that control appetite and body weight. We have identified a link between anabolic energy metabolism and appetite control. Both systemic and intracerebroventricular treatment of mice with fatty acid synthase (FAS) inhibitors (cerulenin and a synthetic compound C75) led to inhibition of feeding and dramatic weight loss. C75 inhibited expression of the prophagic signal neuropeptide Y in the hypothalamus and acted in a leptin-independent manner that appears to be mediated by malonyl-coenzyme A. Thus, FAS may represent an important link in feeding regulation and may be a potential therapeutic target. PMID:10875926

  7. Absence of malonyl coenzyme A decarboxylase in mice increases cardiac glucose oxidation and protects the heart from ischemic injury

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Acute pharmacological inhibition of cardiac malonyl coenzyme A decarboxylase (MCD) protects the heart from ischemic damage by inhibiting fatty acid oxidation and stimulating glucose oxidation. However, it is unknown whether chronic inhibition of MCD results in altered cardiac function, energy metabo...

  8. Zaragozic acids D and D2: potent inhibitors of squalene synthase and of Ras farnesyl-protein transferase.

    PubMed

    Dufresne, C; Wilson, K E; Singh, S B; Zink, D L; Bergstrom, J D; Rew, D; Polishook, J D; Meinz, M; Huang, L; Silverman, K C

    1993-11-01

    Two new zaragozic acids, D and D2, have been isolated from the keratinophilic fungus Amauroascus niger. Zaragozic acids D [4] and D2 [5] are related to the previously described zaragozic acids A [1], B [2], and C [3] and are potent inhibitors of squalene synthase. Furthermore, all the zaragozic acids (A, B, C, D, and D2) are also active against farnesyl transferase. Zaragozic acids D and D2 inhibit farnesyl transferase with IC50 values of 100 nM, while zaragozic acids A and B are less potent. PMID:8289063

  9. Investigation on the ZBG-functionality of phenyl-4-yl-acrylohydroxamic acid derivatives as histone deacetylase inhibitors.

    PubMed

    Musso, Loana; Cincinelli, Raffaella; Zuco, Valentina; Zunino, Franco; Nurisso, Alessandra; Cuendet, Muriel; Giannini, Giuseppe; Vesci, Loredana; Pisano, Claudio; Dallavalle, Sabrina

    2015-10-15

    A series of alternative Zn-binding groups were explored in the design of phenyl-4-yl-acrylohydroxamic acid derivatives as histone deacetylase (HDAC) inhibitors. Most of the synthesized compounds were less effective than the parent hydroxamic acid. However, the profile of activity shown by the analog bearing a hydroxyurea head group, makes this derivative promising for further investigation. PMID:26376355

  10. Isolated etioplasts as test system for inhibitors of fatty acid biosynthesis

    SciTech Connect

    Lichtenthaler, H.K.; Kobek, K. )

    1989-04-01

    Isolated intact chloroplasts of mono- and dicotyledonous plants possess the capacity for de novo fatty acid biosynthesis, starting from {sup 14}C-acetate. These can be taken as test system for herbicides affecting fatty acid biosynthesis as shown earlier in our laboratory. The incorporation rates of acetate into the total fatty acids depend on the photosynthetic cofactors ATP and NADPH and amount in the light to 33 kBq (oat) and 39 kBq (pea) per mg chlorophyll x h, whereas in the dark only ca. 10% of these rates are obtained. In order to establish a test system, which is fully independent of light, we isolated and characterized etioplast fractions from oat and pea seedlings with a very high capacity of de novo fatty acid biosynthesis (500 and 400 kBq per mg carotenoids in a 20 min period). This activity was blocked by herbicides such as cycloxydim, sethoxydim and diclofop in a dose-dependent manner. This new test system has the great advantage that one can verify whether inhibitors of photosynthesis affect fatty acid biosynthesis.

  11. Synthesis of water soluble glycosides of pentacyclic dihydroxytriterpene carboxylic acids as inhibitors of α-glucosidase.

    PubMed

    Xu, Jiancong; Nie, Xuliang; Hong, Yanping; Jiang, Yan; Wu, Guoqiang; Yin, Xiaoli; Wang, Chunrong; Wang, Xiaoqiang

    2016-04-01

    A series of compounds were synthesized by glycosylation of maslinic acid (MA) and corosolic acid (CA) with monosaccharides and disaccharides, and the structures of the derivatives were elucidated by standard spectroscopic methods including (1)H NMR, (13)C NMR and HRMS. The α-glucosidase inhibitory activities of all the novel compounds were evaluated in vitro. The solubility and inhibitory activity of α-glucosidase assays showed that the bis-disaccharide glycosides of triterpene acids possessed higher water solubility and α-glucosidase inhibitory activities than the bis-monosaccharide glycosides. Among these compounds, maslinic acid bis-lactoside (8e, IC50 = 684 µM) and corosolic acid bis-lactoside (9e, IC50 = 428 µM) had the best water solubility, and 9e exhibited a better inhibitory activity than acarbose (IC50 = 478 µM). However, most of glycosylated derivatives possessed lower inhibitory activities than the parent compounds, although their water solubility was enhanced obviously. Moreover, the kinetic inhibition studies indicated that 9e was a non-competitive inhibitor, and structure-activity relationships of the derivatives are also discussed. PMID:26974355

  12. Isoprenoid biosynthesis as a target for antibacterial and antiparasitic drugs: phosphonohydroxamic acids as inhibitors of deoxyxylulose phosphate reducto-isomerase

    PubMed Central

    2004-01-01

    Isoprenoid biosynthesis via the methylerythritol phosphate pathway is a target against pathogenic bacteria and the malaria parasite Plasmodium falciparum. 4-(Hydroxyamino)-4-oxobutylphosphonic acid and 4-[hydroxy(methyl)amino]-4-oxobutyl phosphonic acid, two novel inhibitors of DXR (1-deoxy-D-xylulose 5-phosphate reducto-isomerase), the second enzyme of the pathway, have been synthesized and compared with fosmidomycin, the best known inhibitor of this enzyme. The latter phosphonohydroxamic acid showed a high inhibitory activity towards DXR, much like fosmidomycin, as well as significant antibacterial activity against Escherichia coli in tests on Petri dishes. PMID:15473867

  13. Epigenetic suppression of the antitumor cytotoxicity of NK cells by histone deacetylase inhibitor valproic acid

    PubMed Central

    Shi, Xiumin; Li, Min; Cui, Meizi; Niu, Chao; Xu, Jianting; Zhou, Lei; Li, Wei; Gao, Yushun; Kong, Weisheng; Cui, Jiuwei; Hu, Jifan; Jin, Haofan

    2016-01-01

    Natural killer (NK) cells play an essential role in the fight against tumor development. The therapeutic use of autologous NK cells has been exploited to treat human malignancies, yet only limited antitumor activity is observed in cancer patients. In this study, we sought to augment the antitumor activity of NK cells using epigenetic approaches. Four small molecules that have been known to promote epigenetic reprogramming were tested for their ability to enhance the activity of NK cells. Using a tumor cell lysis assay, we found that the DNA demethylating agent 5-azacytidine and vitamin C did not significantly affect the tumor killing ability of NK cells. The thyroid hormone triiodothyronine (T3) slightly increased the activity of NK cells. The histone deacetylase inhibitor valproic acid (VPA), however, inhibited NK cell lytic activity against leukemic cells in a dose-dependent manner. Pretreatment using VPA reduced IFNγ secretion, impaired CD107a degranulation, and induced apoptosis by activating the PD-1/PD-L1 pathway. VPA downregulated the expression of the activating receptor NKG2D (natural-killer group 2, member D) by inducing histone K9 hypermethylation and DNA methylation in the gene promoter. Histone deacetylase inhibitors have been developed as anticancer agents for use as monotherapies or in combination with other anticancer therapies. Our data suggest that the activity of histone deacetylase inhibitors on NK cell activity should be considered in drug development. PMID:27152238

  14. Snake venoms. The amino acid sequences of two proteinase inhibitor homologues from Dendroaspis angusticeps venom.

    PubMed

    Joubert, F J; Taljaard, N

    1980-05-01

    Toxins C13S1C3 and C13S2C3 from D. angusticeps venom were purified by gel filtration and ion exchange chromatography. Whereas C13S1C3 contains 57 amino acids, C13S2C3 contains 59 but each include six half-cystine residues. The complete primary structure of the low toxicity proteins have been elucidated. The sequences and the invariant residues of toxins C13S1C3 and C13S2C3 from D. angusticeps venom resemble, respectively, those of the proteinase inhibitor homologues K and I from D. polylepis polylepis venom and they are also homologous to the active proteinase inhibitors from various sources. In C13S1C3 and K the active site lysyl residue of active bovine pancreatic proteinase inhibitor is conserved but the site residue alanine, is replaced by lysine. In C13S2C3 and I the active site residue is replaced by tyrosine. PMID:7429422

  15. A pharmaceutical product as corrosion inhibitor for carbon steel in acidic environments.

    PubMed

    Samide, Adriana

    2013-01-01

    A pharmaceutical product, Trimethoprim (TMP), IUPAC name: 5-(3,4,5-trimethoxybenzyl)pyrimidine-2,4-diamine was investigated, as inhibitor to prevent carbon steel corrosion in acidic environments. The study was performed using weight loss and electrochemical measurements, in temperatures ranging between 25-55°C. The surface morphology before and after corrosion of carbon steel in 1.0 M HCl solution in the presence and absence of TMP was evaluated using scanning electron microscopy (SEM). The inhibition efficiency (IE) increased with the increasing of the inhibitor concentration, reaching a maximum value of 92% at 25°C and 0.9 mM TMP, and decreased with increasing temperature. The inhibition of carbon steel corrosion by TMP can be attributed to the adsorption ability of inhibitor molecules onto the reactive sites of the metal surface. The adsorption is spontaneous and it is best described by the Langmuir isotherm. The apparent activation energy (E(a)) for the corrosion process in the absence and presence of TMP was evaluated from Arrhenius equation, to elucidate its inhibitive properties. PMID:23043337

  16. Hydrophobic amino acids as a new class of kinetic inhibitors for gas hydrate formation.

    PubMed

    Sa, Jeong-Hoon; Kwak, Gye-Hoon; Lee, Bo Ram; Park, Da-Hye; Han, Kunwoo; Lee, Kun-Hong

    2013-01-01

    As the foundation of energy industry moves towards gas, flow assurance technology preventing pipelines from hydrate blockages becomes increasingly significant. However, the principle of hydrate inhibition is still poorly understood. Here, we examined natural hydrophobic amino acids as novel kinetic hydrate inhibitors (KHIs), and investigated hydrate inhibition phenomena by using them as a model system. Amino acids with lower hydrophobicity were found to be better KHIs to delay nucleation and retard growth, working by disrupting the water hydrogen bond network, while those with higher hydrophobicity strengthened the local water structure. It was found that perturbation of the water structure around KHIs plays a critical role in hydrate inhibition. This suggestion of a new class of KHIs will aid development of KHIs with enhanced biodegradability, and the present findings will accelerate the improved control of hydrate formation for natural gas exploitation and the utilization of hydrates as next-generation gas capture media. PMID:23938301

  17. Hydrophobic amino acids as a new class of kinetic inhibitors for gas hydrate formation

    PubMed Central

    Sa, Jeong-Hoon; Kwak, Gye-Hoon; Lee, Bo Ram; Park, Da-Hye; Han, Kunwoo; Lee, Kun-Hong

    2013-01-01

    As the foundation of energy industry moves towards gas, flow assurance technology preventing pipelines from hydrate blockages becomes increasingly significant. However, the principle of hydrate inhibition is still poorly understood. Here, we examined natural hydrophobic amino acids as novel kinetic hydrate inhibitors (KHIs), and investigated hydrate inhibition phenomena by using them as a model system. Amino acids with lower hydrophobicity were found to be better KHIs to delay nucleation and retard growth, working by disrupting the water hydrogen bond network, while those with higher hydrophobicity strengthened the local water structure. It was found that perturbation of the water structure around KHIs plays a critical role in hydrate inhibition. This suggestion of a new class of KHIs will aid development of KHIs with enhanced biodegradability, and the present findings will accelerate the improved control of hydrate formation for natural gas exploitation and the utilization of hydrates as next-generation gas capture media. PMID:23938301

  18. Hydrophobic amino acids as a new class of kinetic inhibitors for gas hydrate formation

    NASA Astrophysics Data System (ADS)

    Sa, Jeong-Hoon; Kwak, Gye-Hoon; Lee, Bo Ram; Park, Da-Hye; Han, Kunwoo; Lee, Kun-Hong

    2013-08-01

    As the foundation of energy industry moves towards gas, flow assurance technology preventing pipelines from hydrate blockages becomes increasingly significant. However, the principle of hydrate inhibition is still poorly understood. Here, we examined natural hydrophobic amino acids as novel kinetic hydrate inhibitors (KHIs), and investigated hydrate inhibition phenomena by using them as a model system. Amino acids with lower hydrophobicity were found to be better KHIs to delay nucleation and retard growth, working by disrupting the water hydrogen bond network, while those with higher hydrophobicity strengthened the local water structure. It was found that perturbation of the water structure around KHIs plays a critical role in hydrate inhibition. This suggestion of a new class of KHIs will aid development of KHIs with enhanced biodegradability, and the present findings will accelerate the improved control of hydrate formation for natural gas exploitation and the utilization of hydrates as next-generation gas capture media.

  19. Adsorptive removal of fermentation inhibitors from concentrated acid hydrolyzates of lignocellulosic biomass.

    PubMed

    Sainio, Tuomo; Turku, Irina; Heinonen, Jari

    2011-05-01

    Adsorptive purification of concentrated acid hydrolyzate of lignocellulose was investigated. Cation exchange resin (CS16GC), neutral polymer adsorbent (XAD-16), and granulated activated carbon (GAC) were studied to remove furfural, HMF, and acetic acid from a synthetic hydrolyzate containing 20 wt.% H(2)SO(4). Adsorption isotherms were determined experimentally. Loading and regeneration were investigated in a laboratory scale column. GAC has the highest adsorption capacity, but regeneration with water was not feasible. XAD-16 and CS16GC had lower adsorption capacities but also shorter cycle times due to easier regeneration. Productivity increased when regenerating with 50 wt.% EtOH(aq) solution. To compare adsorbents, process performance was quantified by productivity and fraction of inhibitors removed. GAC yields highest performance when high purity is required and ethanol can be used in regeneration. For lower purities, XAD-16 and GAC yield approximately equal performance. When using ethanol must be avoided, CS16GC offers highest productivity. PMID:21441022

  20. Adaptive laboratory evolution of ethanologenic Zymomonas mobilis strain tolerant to furfural and acetic acid inhibitors.

    PubMed

    Shui, Zong-Xia; Qin, Han; Wu, Bo; Ruan, Zhi-yong; Wang, Lu-shang; Tan, Fu-Rong; Wang, Jing-Li; Tang, Xiao-Yu; Dai, Li-Chun; Hu, Guo-Quan; He, Ming-Xiong

    2015-07-01

    Furfural and acetic acid from lignocellulosic hydrolysates are the prevalent inhibitors to Zymomonas mobilis during cellulosic ethanol production. Developing a strain tolerant to furfural or acetic acid inhibitors is difficul by using rational engineering strategies due to poor understanding of their underlying molecular mechanisms. In this study, strategy of adaptive laboratory evolution (ALE) was used for development of a furfural and acetic acid-tolerant strain. After three round evolution, four evolved mutants (ZMA7-2, ZMA7-3, ZMF3-2, and ZMF3-3) that showed higher growth capacity were successfully obtained via ALE method. Based on the results of profiling of cell growth, glucose utilization, ethanol yield, and activity of key enzymes, two desired strains, ZMA7-2 and ZMF3-3, were achieved, which showed higher tolerance under 7 g/l acetic acid and 3 g/l furfural stress condition. Especially, it is the first report of Z. mobilis strain that could tolerate higher furfural. The best strain, Z. mobilis ZMF3-3, has showed 94.84% theoretical ethanol yield under 3-g/l furfural stress condition, and the theoretical ethanol yield of ZM4 is only 9.89%. Our study also demonstrated that ALE method might also be used as a powerful metabolic engineering tool for metabolic engineering in Z. mobilis. Furthermore, the two best strains could be used as novel host for further metabolic engineering in cellulosic ethanol or future biorefinery. Importantly, the two strains may also be used as novel-tolerant model organisms for the genetic mechanism on the "omics" level, which will provide some useful information for inverse metabolic engineering. PMID:25935346

  1. Click Chemistry in Lead Optimization of Boronic Acids as β-Lactamase Inhibitors.

    PubMed

    Caselli, Emilia; Romagnoli, Chiara; Vahabi, Roza; Taracila, Magdalena A; Bonomo, Robert A; Prati, Fabio

    2015-07-23

    Boronic acid transition-state inhibitors (BATSIs) represent one of the most promising classes of β-lactamase inhibitors. Here we describe a new class of BATSIs, namely, 1-amido-2-triazolylethaneboronic acids, which were synthesized by combining the asymmetric homologation of boronates with copper-catalyzed azide-alkyne cycloaddition for the stereoselective insertion of the amido group and the regioselective formation of the 1,4-disubstituted triazole, respectively. This synthetic pathway, which avoids intermediate purifications, proved to be flexible and efficient, affording in good yields a panel of 14 BATSIs bearing three different R1 amide side chains (acetamido, benzylamido, and 2-thienylacetamido) and several R substituents on the triazole. This small library was tested against two clinically relevant class C β-lactamases from Enterobacter spp. and Pseudomonas aeruginosa. The K(i) value of the best compound (13a) was as low as 4 nM with significant reduction of bacterial resistance to the combination of cefotaxime/13a. PMID:26102369

  2. Integrase Inhibitor Prodrugs: Approaches to Enhancing the Anti-HIV Activity of β-Diketo Acids.

    PubMed

    Nair, Vasu; Okello, Maurice

    2015-01-01

    HIV integrase, encoded at the 3'-end of the HIV pol gene, is essential for HIV replication. This enzyme catalyzes the incorporation of HIV DNA into human DNA, which represents the point of "no-return" in HIV infection. Integrase is a significant target in anti-HIV drug discovery. This review article focuses largely on the design of integrase inhibitors that are β-diketo acids constructed on pyridinone scaffolds. Methodologies for synthesis of these compounds are discussed. Integrase inhibition data for the strand transfer (ST) step are compared with in vitro anti-HIV data. The review also examines the issue of the lack of correlation between the ST enzymology data and anti-HIV assay results. Because this disconnect appeared to be a problem associated with permeability, prodrugs of these inhibitors were designed and synthesized. Prodrugs dramatically improved the anti-HIV activity data. For example, for compound, 96, the anti-HIV activity (EC50) improved from 500 nM for this diketo acid to 9 nM for its prodrug 116. In addition, there was excellent correlation between the IC50 and IC90 ST enzymology data for 96 (6 nM and 97 nM, respectively) and the EC50 and EC90 anti-HIV data for its prodrug 116 (9 nM and 94 nM, respectively). Finally, it was confirmed that the prodrug 116 was rapidly hydrolyzed in cells to the active compound 96. PMID:26184144

  3. Design, synthesis, crystal structures and antimicrobial activity of sulfonamide boronic acids as β-lactamase inhibitors

    PubMed Central

    Eidam, Oliv; Romagnoli, Chiara; Caselli, Emilia; Babaoglu, Kerim; Pohlhaus, Denise Teotico; Karpiak, Joel; Bonnet, Richard; Shoichet, Brian K.; Prati, Fabio

    2010-01-01

    We investigated a series of sulfonamide boronic acids that resulted from the merging of two unrelated AmpC β-lactamase inhibitor series. The new boronic acids differed in the replacement of the canonical carboxamide, found in all penicillin and cephalosporin antibiotics, with a sulfonamide. Surprisingly, these sulfonamides had a highly distinct structure-activity relationship from the previously explored carboxamides, high ligand efficiencies (up to 0.91), Ki values down to 25 nM and up to 23 times better for smaller analogs. Conversely, Ki values were 10 to 20 times worse for larger molecules than in the carboxamide congener series. X-ray crystal structures (1.6–1.8 Å) of AmpC with three of the new sulfonamides suggest that this altered structure-activity relationship results from the different geometry and polarity of the sulfonamide versus the carboxamide. The most potent inhibitor reversed β-lactamase-mediated resistance to third generation cephalosporins, lowering their minimum inhibitory concentrations up to 32-fold in cell culture. PMID:20945905

  4. Pharmacodynamic effects of antibiotics and acid pump inhibitors on Helicobacter pylori.

    PubMed Central

    Sörberg, M; Hanberger, H; Nilsson, M; Nilsson, L E

    1997-01-01

    Pharmacodynamic studies of Helicobacter pylori exposed to amoxicillin, clarithromycin, metronidazole, omeprazole, and lansoprazole were performed with microscopy, viable count determination, and bioluminescence assay of intracellular ATP. The pharmacodynamic parameters determined were change in morphology, change in cell density, postantibiotic effect (PAE), and control-related effective regrowth time (CERT). The PAE is delayed regrowth after brief exposure to antibiotics or acid pump inhibitors. CERT was defined as the time required for the bacteria to resume logarithmic growth and return to the pre-exposure inoculum in the test culture minus the corresponding time for the control culture. CERT measures the combined effect of initial killing and PAE. There was a good concordance between the bioluminescence assay and viable counts for determining CERT, which makes this parameter useful for pharmacodynamic studies of the effects of antibiotics and acid pump inhibitors on H. pylori. Amoxicillin and metronidazole produced a strong, concentration-dependent initial decrease in CFU per milliliter, but there was a less prominent initial change in intracellular ATP in these cultures. Amoxicillin caused a long PAE when assayed by the bioluminescence assay but no PAE or a negative PAE when assayed by viable count determination. However, amoxicillin showed similar long CERTs with both methods. The pharmacodynamic effects of amoxicillin were concentration dependent up to a maximum response, indicating that concentrations above this level do not increase the antibiotic effect. The PAEs and CERTs of clarithromycin and metronidazole were concentration dependent with no maximum response. With omeprazole and lanzoprazole, there was no PAE or CERT. PMID:9333051

  5. The myeloperoxidase product hypochlorous acid generates irreversible high-density lipoprotein receptor inhibitors

    PubMed Central

    Binder, Veronika; Ljubojevic, Senka; Haybaeck, Johannes; Holzer, Michael; El-Gamal, Dalia; Schicho, Rudolf; Pieske, Burkert; Heinemann, Akos; Marsche, Gunther

    2014-01-01

    Objective Elevated levels of advanced oxidation protein products (AOPPs) have been described in several chronic inflammatory diseases, like chronic renal insufficiency, rheumatoid arthritis and atherosclerosis. Recent findings revealed that AOPPs are inhibitors of the major high-density lipoprotein (HDL) receptor, scavenger receptor class B, type 1 (SR-BI). Here we investigated what oxidation induced structural alterations convert plasma albumin into an HDL-receptor inhibitor. Approach and Results Exposure of albumin to the physiological oxidant, hypochlorous acid, generated high affinity SR-BI ligands. Protection of albumin lysine-residues prior exposure to hypochlorous acid as well as regeneration of N-chloramines after oxidation of albumin completely prevented binding of oxidized albumin to SR-BI, indicating that modification of albumin lysine-residues is required to generate SR-BI ligands. Of particular interest, N-chloramines within oxidized albumin promoted irreversible binding to SR-BI, resulting in permanent receptor blockade. We observed that the SR-BI inhibitory activity of albumin isolated from chronic kidney disease patients correlated with the content of the myeloperoxidase-specific oxidation product 3-chlorotyrosine and was associated with alterations in the composition of HDL. Conclusion Given that several potential atheroprotective activities of HDL are mediated by SR-BI, the present results raise the possibility that oxidized plasma albumin, through permanent SR-BI blockade, contributes to the pathophysiology of cardiovascular disease. PMID:23493288

  6. Herbicidal inhibitors of amino acid biosynthesis and herbicide-tolerant crops.

    PubMed

    Tan, S; Evans, R; Singh, B

    2006-03-01

    Acetohydroxyacid synthase (AHAS) inhibitors interfere with branched-chain amino acid biosynthesis by inhibiting AHAS. Glyphosate affects aromatic amino acid biosynthesis by inhibiting 5-enolpyruvylshikimate-3-phosphate synthase (EPSPS). Glufosinate inhibits glutamine synthetase and blocks biosynthesis of glutamine. AHAS gene variants that confer tolerance to AHAS inhibitors have been discovered in plants through selection or mutagenesis. Imidazolinone-tolerant crops have been commercialized based on these AHAS gene variants. A modified maize EPSPS gene and CP4-EPSPS gene from Agrobacterium sp. have been used to transform plants for target-based tolerance to glyphosate. A gox gene isolated from Ochrobactrum anthropi has also been employed to encode glyphosate oxidoreductase to detoxify glyphosate in plants. Glyphosate-tolerant crops with EPSPS transgene alone or both EPSPS and gox transgenes have been commercialized. Similarly, bar and pat genes isolated from Streptomyces hygroscopicus and S. viridochromogenes, respectively, have been inserted into plants to encode phosphinothricin N-acetyltransferase to detoxify glufosinate. Glufosinate-tolerant crops have been commercialized using one of these two transgenes. PMID:16547651

  7. Amino acid amides of piperic acid (PA) and 4-ethylpiperic acid (EPA) as NorA efflux pump inhibitors of Staphylococcus aureus.

    PubMed

    Wani, Naiem Ahmad; Singh, Samsher; Farooq, Saleem; Shankar, Sudha; Koul, Surrinder; Khan, Inshad Ali; Rai, Rajkishor

    2016-09-01

    A total of eighteen piperic acid (PA) and 4-ethylpiperic acid (EPA) amides (C1-C18) with α-, β- and γ-amino acids were synthesized, characterized and evaluated for their efflux pump inhibitory activity against ciprofloxacin resistant Staphylococcus aureus. The amides were screened against NorA overexpressing S. aureus SA-1199B and wild type S. aureus SA-1199 using ethidium bromide as NorA efflux pump substrate. EPI C6 was found to be most potent and reduced the MIC of ciprofloxacin by 16 fold followed by C18 which showed 4 fold reduction of MIC. Ethidium bromide efflux inhibition and accumulation assay proved these compounds as NorA inhibitors. PMID:27503686

  8. Observation of superoxide production during catalysis of Bacillus subtilis oxalate decarboxylase at pH 4.

    PubMed

    Twahir, Umar T; Stedwell, Corey N; Lee, Cory T; Richards, Nigel G J; Polfer, Nicolas C; Angerhofer, Alexander

    2015-03-01

    This contribution describes the trapping of the hydroperoxyl radical at a pH of 4 during turnover of wild-type oxalate decarboxylase and its T165V mutant using the spin-trap BMPO. Radicals were detected and identified by a combination of EPR and mass spectrometry. Superoxide, or its conjugate acid, the hydroperoxyl radical, is expected as an intermediate in the decarboxylation and oxidation reactions of the oxalate monoanion, both of which are promoted by oxalate decarboxylase. Another intermediate, the carbon dioxide radical anion was also observed. The quantitative yields of superoxide trapping are similar in the wild type and the mutant while it is significantly different for the trapping of the carbon dioxide radical anion. This suggests that the two radicals are released from different sites of the protein. PMID:25526893

  9. Observation of Superoxide Production During Catalysis of Bacillus subtilis Oxalate Decarboxylase at pH4

    PubMed Central

    Twahir, Umar T.; Stedwell, Corey N.; Lee, Cory T.; Richards, Nigel G. J.; Polfer, Nicolas C.; Angerhofer, Alexander

    2015-01-01

    This contribution describes the trapping of the hydroperoxyl radical at a pH of 4 during turnover of wild-type oxalate decarboxylase and its T165V mutant using the spin trap BMPO. Radicals were detected and identified by a combination of EPR and mass spectrometry. Superoxide, or its conjugate acid, the hydroperoxyl radical, is expected as an intermediate in the decarboxylation and oxidation reactions of the oxalate monoanion both of which are promoted by oxalate decarboxylase. Another intermediate, the carbon dioxide radical anion was also observed. The quantitative yields of superoxide trapping is similar in the wild type and the mutant while it is significantly different for the trapping of the carbon dioxide radical anion. This suggests that the two radicals are released from different sites of the protein. PMID:25526893

  10. Cloning and characterization of indolepyruvate decarboxylase from Methylobacterium extorquens AM1.

    PubMed

    Fedorov, D N; Doronina, N V; Trotsenko, Yu A

    2010-12-01

    For the first time for methylotrophic bacteria an enzyme of phytohormone indole-3-acetic acid (IAA) biosynthesis, indole-3-pyruvate decarboxylase (EC 4.1.1.74), has been found. An open reading frame (ORF) was identified in the genome of facultative methylotroph Methylobacterium extorquens AM1 using BLAST. This ORF encodes thiamine diphosphate-dependent 2-keto acid decarboxylase and has similarity with indole-3-pyruvate decarboxylases, which are key enzymes of IAA biosynthesis. The ORF of the gene, named ipdC, was cloned into overexpression vector pET-22b(+). Recombinant enzyme IpdC was purified from Escherichia coli BL21(DE3) and characterized. The enzyme showed the highest k(cat) value for benzoylformate, albeit the indolepyruvate was decarboxylated with the highest catalytic efficiency (k(cat)/K(m)). The molecular mass of the holoenzyme determined using gel-permeation chromatography corresponds to a 245-kDa homotetramer. An ipdC-knockout mutant of M. extorquens grown in the presence of tryptophan had decreased IAA level (46% of wild type strain). Complementation of the mutation resulted in 6.3-fold increase of IAA concentration in the culture medium compared to that of the mutant strain. Thus involvement of IpdC in IAA biosynthesis in M. extorquens was shown. PMID:21314613

  11. Theoretical study of inhibition efficiencies of some amino acids on corrosion of carbon steel in acidic media: green corrosion inhibitors.

    PubMed

    Dehdab, Maryam; Shahraki, Mehdi; Habibi-Khorassani, Sayyed Mostafa

    2016-01-01

    Inhibition efficiencies of three amino acids [tryptophan (B), tyrosine (c), and serine (A)] have been studied as green corrosion inhibitors on corrosion of carbon steel using density functional theory (DFT) method in gas and aqueous phases. Quantum chemical parameters such as EH OMO (highest occupied molecular orbital energy), E LUMO (lowest unoccupied molecular orbital energy), hardness (η), polarizability ([Formula: see text]), total negative charges on atoms (TNC), molecular volume (MV) and total energy (TE) have been calculated at the B3LYP level of theory with 6-311++G** basis set. Consistent with experimental data, theoretical results showed that the order of inhibition efficiency is tryptophan (B) > tyrosine (C) > serine (A). In order to determine the possible sites of nucleophilic and electrophilic attacks, local reactivity has been evaluated through Fukui indices. PMID:26347374

  12. Substitution of the phosphonic acid and hydroxamic acid functionalities of the DXR inhibitor FR900098: an attempt to improve the activity against Mycobacterium tuberculosis.

    PubMed

    Andaloussi, Mounir; Lindh, Martin; Björkelid, Christofer; Suresh, Surisetti; Wieckowska, Anna; Iyer, Harini; Karlén, Anders; Larhed, Mats

    2011-09-15

    Two series of FR900098/fosmidomycin analogs were synthesized and evaluated for MtDXR inhibition and Mycobacterium tuberculosis whole-cell activity. The design rationale of these compounds involved the exchange of either the phosphonic acid or the hydroxamic acid part for alternative acidic and metal-coordinating functionalities. The best inhibitors provided IC(50) values in the micromolar range, with a best value of 41 μM. PMID:21824775

  13. Structural determinants for the inhibitory ligands of orotidine-5′-monophosphate decarboxylase

    SciTech Connect

    Meza-Avina, Maria Elena; Wei, Lianhu; Liu, Yan; Poduch, Ewa; Bello, Angelica M.; Mishra, Ram K.; Pai, Emil F.; Kotra, Lakshmi P.

    2010-06-14

    In recent years, orotidine-5{prime}-monophosphate decarboxylase (ODCase) has gained renewed attention as a drug target. As a part of continuing efforts to design novel inhibitors of ODCase, we undertook a comprehensive study of potent, structurally diverse ligands of ODCase and analyzed their structural interactions in the active site of ODCase. These ligands comprise of pyrazole or pyrimidine nucleotides including the mononucleotide derivatives of pyrazofurin, barbiturate ribonucleoside, and 5-cyanouridine, as well as, in a computational approach, 1,4-dihydropyridine-based non-nucleoside inhibitors such as nifedipine and nimodipine. All these ligands bind in the active site of ODCase exhibiting distinct interactions paving the way to design novel inhibitors against this interesting enzyme. We propose an empirical model for the ligand structure for rational modifications in new drug design and potentially new lead structures.

  14. Structural Determinants for Inhibitory Ligands of Orotidine-5′-Monophosphate Decarboxylase

    PubMed Central

    Meza-Avina, Maria Elena; Wei, Lianhu; Liu, Yan; Poduch, Ewa; Bello, Angelica M.; Mishra, Ram K.; Pai, Emil F.; Kotra, Lakshmi P.

    2011-01-01

    In recent years, orotidine-5′-monophosphate decarboxylase (ODCase) has gained renewed attention as a drug target. As a part of continuing efforts to design novel inhibitors of ODCase, we undertook a comprehensive study of potent, structurally diverse ligands of ODCase and analyzed their structural interactions in the active site of ODCase. These ligands comprise of pyrazole or pyrimidine nucleotides including the mononucleotide derivatives of pyrazofurin, barbiturate ribonucleoside, and 5-cyanouridine, as well as, in a computational approach, 1,4-dihydropyridine-based non-nucleoside inhibitors such as nifedipine and nimodipine. All these ligands bind in the active site of ODCase exhibiting distinct interactions paving the way to design novel inhibitors against this interesting enzyme. We propose an empirical model for the ligand structure for rational modifications in new drug design and potentially new lead structures. PMID:20452222

  15. Dianils: New and effective corrosion inhibitors for oil-well steel (N-80) and mild steel in boiling hydrochloric acid

    SciTech Connect

    Quraishi, M.A.; Jamal, D.

    2000-02-01

    Selected condensation products of aromatic aldehydes and p-phenylenediamine have been synthesized and evaluated as corrosion inhibitors for mild steel (MS) and oil-well steel (N-80) in 15% hydrochloric acid (HCl) at 105 C {+-} 2 C by the weight loss method. All the condensation products showed excellent performance. 2,4-dicinnamyledene aminophenylene (DCAP) was found to be the best corrosion inhibitor. It exhibited 99.75% inhibition efficiency (IE) for MS and 99.12% for N-80 steel at 5,000 ppm of inhibitor concentration. The potentiodynamic polarization studies carried out at room temperature on MS in 15% HCl containing 500 ppm of condensation products showed that all the investigated compounds were mixed type inhibitors, whereas 500 ppm DCAP on N-80 steel behaved predominantly as anodic inhibitors. The adsorption of all the condensation products was found to obey Temkin's adsorption isotherm.

  16. Pharmacokinetics, pharmacodynamics, and safety of lesinurad, a selective uric acid reabsorption inhibitor, in healthy adult males.

    PubMed

    Shen, Zancong; Rowlings, Colin; Kerr, Brad; Hingorani, Vijay; Manhard, Kimberly; Quart, Barry; Yeh, Li-Tain; Storgard, Chris

    2015-01-01

    Lesinurad is a selective uric acid reabsorption inhibitor under investigation for the treatment of gout. Single and multiple ascending dose studies were conducted to evaluate pharmacokinetics, pharmacodynamics, and safety of lesinurad in healthy males. Lesinurad was administered as an oral solution between 5 mg and 600 mg (single ascending dose; N=34) and as an oral solution or immediate-release capsules once daily (qday) between 100 mg and 400 mg for 10 days under fasted or fed condition (multiple ascending dose; N=32). Following single doses of lesinurad solution, absorption was rapid and exposure (maximum observed plasma concentration and area under the plasma concentration-time curve) increased in a dose-proportional manner. Following multiple qday doses, there was no apparent accumulation of lesinurad. Urinary excretion of unchanged lesinurad was generally between 30% and 40% of dose. Increases in urinary excretion of uric acid and reductions in serum uric acid correlated with dose. Following 400 mg qday dosing, serum uric acid reduction was 35% at 24 hours post-dose, supporting qday dosing. A relative bioavailability study in healthy males (N=8) indicated a nearly identical pharmacokinetic profile following dosing of tablets or capsules. Lesinurad was generally safe and well tolerated. PMID:26170627

  17. Pharmacokinetics, pharmacodynamics, and safety of lesinurad, a selective uric acid reabsorption inhibitor, in healthy adult males

    PubMed Central

    Shen, Zancong; Rowlings, Colin; Kerr, Brad; Hingorani, Vijay; Manhard, Kimberly; Quart, Barry; Yeh, Li-Tain; Storgard, Chris

    2015-01-01

    Lesinurad is a selective uric acid reabsorption inhibitor under investigation for the treatment of gout. Single and multiple ascending dose studies were conducted to evaluate pharmacokinetics, pharmacodynamics, and safety of lesinurad in healthy males. Lesinurad was administered as an oral solution between 5 mg and 600 mg (single ascending dose; N=34) and as an oral solution or immediate-release capsules once daily (qday) between 100 mg and 400 mg for 10 days under fasted or fed condition (multiple ascending dose; N=32). Following single doses of lesinurad solution, absorption was rapid and exposure (maximum observed plasma concentration and area under the plasma concentration–time curve) increased in a dose-proportional manner. Following multiple qday doses, there was no apparent accumulation of lesinurad. Urinary excretion of unchanged lesinurad was generally between 30% and 40% of dose. Increases in urinary excretion of uric acid and reductions in serum uric acid correlated with dose. Following 400 mg qday dosing, serum uric acid reduction was 35% at 24 hours post-dose, supporting qday dosing. A relative bioavailability study in healthy males (N=8) indicated a nearly identical pharmacokinetic profile following dosing of tablets or capsules. Lesinurad was generally safe and well tolerated. PMID:26170627

  18. Basic Quinolinonyl Diketo Acid Derivatives as Inhibitors of HIV Integrase and their Activity against RNase H Function of Reverse Transcriptase

    PubMed Central

    2015-01-01

    A series of antiviral basic quinolinonyl diketo acid derivatives were developed as inhibitors of HIV-1 IN. Compounds 12d,f,i inhibited HIV-1 IN with IC50 values below 100 nM for strand transfer and showed a 2 order of magnitude selectivity over 3′-processing. These strand transfer selective inhibitors also inhibited HIV-1 RNase H with low micromolar potencies. Molecular modeling studies based on both the HIV-1 IN and RNase H catalytic core domains provided new structural insights for the future development of these compounds as dual HIV-1 IN and RNase H inhibitors. PMID:24684270

  19. Purification and properties of diaminopimelate decarboxylase from Escherichia coli

    PubMed Central

    White, P. J.; Kelly, Bridget

    1965-01-01

    1. Diaminopimelate decarboxylase from a soluble extract of Escherichia coli A.T.C.C. 9637 was purified 200-fold by precipitation of nucleic acids, fractionation with acetone and then with ammonium sulphate, adsorption on calcium phosphate gel and chromatography on DEAE-cellulose or DEAE-Sephadex. 2. The purified enzyme showed only one component in the ultracentrifuge, with a sedimentation coefficient of 5·4s. One major peak and three much smaller peaks were observed on electrophoresis of the enzyme at pH8·9. 3. The mol.wt. of the enzyme was approx. 200000. The catalytic constant was 2000mol. of meso-diaminopimelic acid decomposed/min./mol. of enzyme, at 37°. The relative rates of decarboxylation at 25°, 37° and 45° were 0·17:1·0:1·6. At 37° the Michaelis constant was 1·7mm and the optimum pH was 6·7–6·8. 4. There was an excess of acidic amino acids over basic amino acids in the enzyme, which was bound only on basic cellulose derivatives at pH6·8. 5. The enzyme had an absolute requirement for pyridoxal phosphate as a cofactor; no other derivative of pyridoxine had activity. A thiol compound (of which 2,3-dimercaptopropan-1-ol was the most effective) was also needed as an activator. 6. In the presence of 2,3-dimercaptopropan-1-ol (1mm), heavy-metal ions (Cu2+, Hg2+) did not inhibit the enzyme, but there was inhibition by several amino acids with analogous structures to diaminopimelate, generally at high concentrations relative to the substrate. Penicillamine was inhibitory at relatively low concentrations; its action was prevented by pyridoxal phosphate. PMID:14343156

  20. Dipeptide boronic acid inhibitors of dipeptidyl peptidase IV: determinants of potency and in vivo efficacy and safety.

    PubMed

    Connolly, Beth A; Sanford, David G; Chiluwal, Amrita K; Healey, Sarah E; Peters, Diane E; Dimare, Matthew T; Wu, Wengen; Liu, Yuxin; Maw, Hlaing; Zhou, Yuhong; Li, Youhua; Jin, Zhiping; Sudmeier, James L; Lai, Jack H; Bachovchin, William W

    2008-10-01

    Dipeptidyl peptidase IV (DPP-IV; E.C. 3.4.14.5), a serine protease that degrades the incretin hormones GLP-1 and GIP, is now a validated target for the treatment of type 2 diabetes. Dipeptide boronic acids, among the first, and still among the most potent DPP-IV inhibitors known, suffer from a concern over their safety. Here we evaluate the potency, in vivo efficacy, and safety of a selected set of these inhibitors. The adverse effects induced by boronic acid-based DPP-IV inhibitors are essentially limited to what has been observed previously for non-boronic acid inhibitors and attributed to cross-reactivity with DPP8/9. While consistent with the DPP8/9 hypothesis, they are also consistent with cross-reactivity with some other intracellular target. The results further show that the potency of simple dipeptide boronic acid-based inhibitors can be combined with selectivity against DPP8/9 in vivo to produce agents with a relatively wide therapeutic index (>500) in rodents. PMID:18783201

  1. Valproic Acid as a Potential Inhibitor of Plasmodium falciparum Histone Deacetylase 1 (PfHDAC1): An in Silico Approach

    PubMed Central

    Elbadawi, Mohamed A. Abdallah; Awadalla, Mohamed Khalid Alhaj; Abdel Hamid, Muzamil Mahdi; Mohamed, Magdi Awadalla; Awad, Talal Ahmed

    2015-01-01

    A new Plasmodium falciparum histone deacetylase1 (PfHDAC1) homology model was built based on the highest sequence identity available template human histone deacetylase 2 structure. The generated model was carefully evaluated for stereochemical accuracy, folding correctness and overall structure quality. All evaluations were acceptable and consistent. Docking a group of hydroxamic acid histone deacetylase inhibitors and valproic acid has shown binding poses that agree well with inhibitor-bound histone deacetylase-solved structural interactions. Docking affinity dG scores were in agreement with available experimental binding affinities. Further, enzyme-ligand complex stability and reliability were investigated by running 5-nanosecond molecular dynamics simulations. Thorough analysis of the simulation trajectories has shown that enzyme-ligand complexes were stable during the simulation period. Interestingly, the calculated theoretical binding energies of the docked hydroxamic acid inhibitors have shown that the model can discriminate between strong and weaker inhibitors and agrees well with the experimental affinities reported in the literature. The model and the docking methodology can be used in screening virtual libraries for PfHDAC1 inhibitors, since the docking scores have ranked ligands in accordance with experimental binding affinities. Valproic acid calculated theoretical binding energy suggests that it may inhibit PfHDAC1. PMID:25679451

  2. Concentrated sulfite-yeast fermenting mixture as a corrosion inhibitor of copper in mixtures of sulfuric and nitric acid

    SciTech Connect

    Agaev, N.M.; Smorodin, A.E.; Rzaev, E.R.; Tyr, S.G.; Shlimak, Ya.B.; Geidarova, G.D.; Eremeeva, R.A.; Nasirov, G.N.

    1987-03-01

    At the Baku factory of residential air conditioning systems both preliminary and final pickling of copper tubing is carried out in a solution of sulfuric and nitric acids. The authors of this study, in seeking an inhibitor to control this process, evaluate the protective properties of an inhibitor based on a concentrated sulfite-yeast fermenting mixture that is generated as a common waste product by the cellulose-pulp industry. It consists of calcium, sodium, and ammonium salts of lignin sulfonic acids. Tests revealed not only its inhibiting effectiveness but also its capacity to lower toxic gas levels of nitrogen oxides in the plant environment.

  3. Improvement of dolichol-linked oligosaccharide biosynthesis by the squalene synthase inhibitor zaragozic acid.

    PubMed

    Haeuptle, Micha A; Welti, Michael; Troxler, Heinz; Hülsmeier, Andreas J; Imbach, Timo; Hennet, Thierry

    2011-02-25

    The majority of congenital disorders of glycosylation (CDG) are caused by defects of dolichol (Dol)-linked oligosaccharide assembly, which lead to under-occupancy of N-glycosylation sites. Most mutations encountered in CDG are hypomorphic, thus leaving residual activity to the affected biosynthetic enzymes. We hypothesized that increased cellular levels of Dol-linked substrates might compensate for the low biosynthetic activity and thereby improve the output of protein N-glycosylation in CDG. To this end, we investigated the potential of the squalene synthase inhibitor zaragozic acid A to redirect the flow of the polyisoprene pathway toward Dol by lowering cholesterol biosynthesis. The addition of zaragozic acid A to CDG fibroblasts with a Dol-P-Man synthase defect led to the formation of longer Dol-P species and to increased Dol-P-Man levels. This treatment was shown to decrease the pathologic accumulation of incomplete Dol pyrophosphate-GlcNAc(2)Man(5) in Dol-P-Man synthase-deficient fibroblasts. Zaragozic acid A treatment also decreased the amount of truncated protein N-linked oligosaccharides in these CDG fibroblasts. The increased cellular levels of Dol-P-Man and possibly the decreased cholesterol levels in zaragozic acid A-treated cells also led to increased availability of the glycosylphosphatidylinositol anchor as shown by the elevated cell-surface expression of the CD59 protein. This study shows that manipulation of the cellular Dol pool, as achieved by zaragozic acid A addition, may represent a valuable approach to improve N-linked glycosylation in CDG cells. PMID:21183681

  4. Improvement of Dolichol-linked Oligosaccharide Biosynthesis by the Squalene Synthase Inhibitor Zaragozic Acid*

    PubMed Central

    Haeuptle, Micha A.; Welti, Michael; Troxler, Heinz; Hülsmeier, Andreas J.; Imbach, Timo; Hennet, Thierry

    2011-01-01

    The majority of congenital disorders of glycosylation (CDG) are caused by defects of dolichol (Dol)-linked oligosaccharide assembly, which lead to under-occupancy of N-glycosylation sites. Most mutations encountered in CDG are hypomorphic, thus leaving residual activity to the affected biosynthetic enzymes. We hypothesized that increased cellular levels of Dol-linked substrates might compensate for the low biosynthetic activity and thereby improve the output of protein N-glycosylation in CDG. To this end, we investigated the potential of the squalene synthase inhibitor zaragozic acid A to redirect the flow of the polyisoprene pathway toward Dol by lowering cholesterol biosynthesis. The addition of zaragozic acid A to CDG fibroblasts with a Dol-P-Man synthase defect led to the formation of longer Dol-P species and to increased Dol-P-Man levels. This treatment was shown to decrease the pathologic accumulation of incomplete Dol pyrophosphate-GlcNAc2Man5 in Dol-P-Man synthase-deficient fibroblasts. Zaragozic acid A treatment also decreased the amount of truncated protein N-linked oligosaccharides in these CDG fibroblasts. The increased cellular levels of Dol-P-Man and possibly the decreased cholesterol levels in zaragozic acid A-treated cells also led to increased availability of the glycosylphosphatidylinositol anchor as shown by the elevated cell-surface expression of the CD59 protein. This study shows that manipulation of the cellular Dol pool, as achieved by zaragozic acid A addition, may represent a valuable approach to improve N-linked glycosylation in CDG cells. PMID:21183681

  5. Identification and analysis of hepatitis C virus NS3 helicase inhibitors using nucleic acid binding assays

    PubMed Central

    Mukherjee, Sourav; Hanson, Alicia M.; Shadrick, William R.; Ndjomou, Jean; Sweeney, Noreena L.; Hernandez, John J.; Bartczak, Diana; Li, Kelin; Frankowski, Kevin J.; Heck, Julie A.; Arnold, Leggy A.; Schoenen, Frank J.; Frick, David N.

    2012-01-01

    Typical assays used to discover and analyze small molecules that inhibit the hepatitis C virus (HCV) NS3 helicase yield few hits and are often confounded by compound interference. Oligonucleotide binding assays are examined here as an alternative. After comparing fluorescence polarization (FP), homogeneous time-resolved fluorescence (HTRF®; Cisbio) and AlphaScreen® (Perkin Elmer) assays, an FP-based assay was chosen to screen Sigma’s Library of Pharmacologically Active Compounds (LOPAC) for compounds that inhibit NS3-DNA complex formation. Four LOPAC compounds inhibited the FP-based assay: aurintricarboxylic acid (ATA) (IC50 = 1.4 μM), suramin sodium salt (IC50 = 3.6 μM), NF 023 hydrate (IC50 = 6.2 μM) and tyrphostin AG 538 (IC50 = 3.6 μM). All but AG 538 inhibited helicase-catalyzed strand separation, and all but NF 023 inhibited replication of subgenomic HCV replicons. A counterscreen using Escherichia coli single-stranded DNA binding protein (SSB) revealed that none of the new HCV helicase inhibitors were specific for NS3h. However, when the SSB-based assay was used to analyze derivatives of another non-specific helicase inhibitor, the main component of the dye primuline, it revealed that some primuline derivatives (e.g. PubChem CID50930730) are up to 30-fold more specific for HCV NS3h than similarly potent HCV helicase inhibitors. PMID:22740655

  6. Synthesis and biological evaluation of enantiomerically pure glyceric acid derivatives as LpxC inhibitors.

    PubMed

    Tangherlini, Giovanni; Torregrossa, Tullio; Agoglitta, Oriana; Köhler, Jens; Melesina, Jelena; Sippl, Wolfgang; Holl, Ralph

    2016-03-01

    Inhibitors of the UDP-3-O-[(R)-3-hydroxymyristoyl]-N-acetylglucosamine deacetylase (LpxC) represent a promising class of novel antibiotics, selectively combating Gram-negative bacteria. In order to elucidate the impact of the hydroxymethyl groups of diol (S,S)-4 on the inhibitory activity against LpxC, glyceric acid ethers (R)-7a, (S)-7a, (R)-7b, and (S)-7b, lacking the hydroxymethyl group in benzylic position, were synthesized. The compounds were obtained in enantiomerically pure form by a chiral pool synthesis and a lipase-catalyzed enantioselective desymmetrization, respectively. The enantiomeric hydroxamic acids (R)-7b (Ki=230nM) and (S)-7b (Ki=390nM) show promising enzyme inhibition. However, their inhibitory activities do not substantially differ from each other leading to a low eudismic ratio. Generally, the synthesized glyceric acid derivatives 7 show antibacterial activities against two Escherichia coli strains exceeding the ones of their respective regioisomes 6. PMID:26827141

  7. New metabolically stabilized analogues of lysophosphatidic acid: agonists, antagonists and enzyme inhibitors.

    PubMed

    Prestwich, G D; Xu, Y; Qian, L; Gajewiak, J; Jiang, G

    2005-12-01

    Lysophosphatidic acid (LPA) is a metabolically labile natural phospholipid with a bewildering array of physiological effects. We describe herein a variety of long-lived receptor-specific agonists and antagonists for LPA receptors. Several LPA and PA (phosphatidic acid) analogues also inhibit LPP (lipid phosphate phosphatase). The sn-1 or sn-2 hydroxy groups have been replaced by fluorine, difluoromethyl, difluoroethyl, O-methyl or O-hydroxyethoxy groups to give non-migrating LPA analogues that resist acyltransferases. Alkyl ether replacement of acyl esters produced lipase and acyltransferase-resistant analogues. Replacement of the bridging oxygen in the monophosphate by an alpha-monofluoromethylene-, alpha-bromomethylene- or alpha,alpha-difluoromethylenephosphonate gave phosphatase-resistant analogues. Phosphorothioate analogues with O-acyl and O-alkyl chains are potent, long-lived agonists for LPA1 and LPA3 receptors. Most recently, we have (i) prepared stabilized O-alkyl analogues of lysobisphosphatidic acid, (ii) explored the structure-activity relationship of stabilized cyclic LPA analogues and (iii) synthesized neutral head group trifluoromethylsulphonamide analogues of LPA. Through collaborative studies, we have collected data for these stabilized analogues as selective LPA receptor (ant)agonists, LPP inhibitors, TREK (transmembrane calcium channel) K+ channel agonists, activators of the nuclear transcription factor PPAR-gamma (peroxisome-proliferator-activated receptor-gamma), promoters of cell motility and survival, and radioprotectants for human B-cells. PMID:16246118

  8. Effects of the Histone Deacetylase Inhibitor Valproic Acid on Human Pericytes In Vitro

    PubMed Central

    Friman, Tomas; Dencker, Lennart; Sundberg, Christian; Scholz, Birger

    2011-01-01

    Microvascular pericytes are of key importance in neoformation of blood vessels, in stabilization of newly formed vessels as well as maintenance of angiostasis in resting tissues. Furthermore, pericytes are capable of differentiating into pro-fibrotic collagen type I producing fibroblasts. The present study investigates the effects of the histone deacetylase (HDAC) inhibitor valproic acid (VPA) on pericyte proliferation, cell viability, migration and differentiation. The results show that HDAC inhibition through exposure of pericytes to VPA in vitro causes the inhibition of pericyte proliferation and migration with no effect on cell viability. Pericyte exposure to the potent HDAC inhibitor Trichostatin A caused similar effects on pericyte proliferation, migration and cell viability. HDAC inhibition also inhibited pericyte differentiation into collagen type I producing fibroblasts. Given the importance of pericytes in blood vessel biology a qPCR array focusing on the expression of mRNAs coding for proteins that regulate angiogenesis was performed. The results showed that HDAC inhibition promoted transcription of genes involved in vessel stabilization/maturation in human microvascular pericytes. The present in vitro study demonstrates that VPA influences several aspects of microvascular pericyte biology and suggests an alternative mechanism by which HDAC inhibition affects blood vessels. The results raise the possibility that HDAC inhibition inhibits angiogenesis partly through promoting a pericyte phenotype associated with stabilization/maturation of blood vessels. PMID:21966390

  9. Valproic Acid and Other HDAC Inhibitors Induce Microglial Apoptosis and Attenuate Lipopolysaccharide- induced Dopaminergic Neurotoxicity

    PubMed Central

    Chen, Po See; Wang, Chao-Chuan; Bortner, Carl D.; Peng, Giia-Sheun; Wu, Xuefei; Pang, Hao; Lu, Ru-Band; Gean, Po-Wu; Chuang, De-Maw; Hong, Jau-Shyong

    2009-01-01

    Valproic acid (VPA), a widely prescribed drug for seizures and bipolar disorder, has been shown to be an inhibitor of histone deacetylase (HDAC). Our previous study has demonstrated that VPA pretreatment reduces lipopolysaccharide (LPS)-induced dopaminergic (DA) neurotoxicity through the inhibition of microglia over-activation. The aim of this study was to determine the mechanism underlying VPA-induced attenuation of microglia over-activation. Other HDAC inhibitors (HDACIs) were compared with VPA for their effects on microglial activity. We found that VPA induced apoptosis of microglia cells in a time and concentration-dependent manner. VPA-treated microglial cells showed typical apoptotic hallmarks including phosphatidylserine externalization, chromatin condensation and DNA fragmentation. Further studies revealed that trichostatin A (TSA) and sodium butyrate (SB), two structurally dissimilar HDACIs, also induced microglial apoptosis. The apoptosis of microglia was accompanied by the disruption of mitochondrial membrane potential and the enhancement of acetylation levels of the histone H3 protein. Moreover, pretreatment with SB or TSA caused a robust decrease in LPS-induced pro-inflammatory responses and protected DA neurons from damage in mesencephalic neuron-glia cultures. Taken together, our results shed light on a novel mechanism whereby HDACIs induce neuroprotection and underscore the potential utility of HDACIs in preventing inflammation-related neurodegenerative disorders such as Parkinson’s disease. PMID:17850978

  10. Combined kinetic studies and computational analysis on kojic acid analogous as tyrosinase inhibitors.

    PubMed

    Lima, Carlyle Ribeiro; Silva, José Rogério A; de Tássia Carvalho Cardoso, Erica; Silva, Edilene O; Lameira, Jerônimo; do Nascimento, José Luiz Martins; do Socorro Barros Brasil, Davi; Alves, Cláudio N

    2014-01-01

    Tyrosinase is a key enzyme in melanin synthesis and widely distributed in plants and animals tissues. In mammals, this enzyme is related to pigment production, involved in wound healing, primary immune response and it can also contribute to catecholamines synthesis in the brain. Consequently, tyrosinase enzyme represents an attractive and selective target in the field of the medicine, cosmetics and bio-insecticides. In this paper, experimental kinetics and computational analysis were used to study the inhibition of tyrosinase by analogous of Kojic acid. The main interactions occurring between inhibitors-tyrosinase complexes and the influence of divalent cation (Cu2+) in enzymatic inhibition were investigated by using molecular docking, molecular dynamic simulations and electrostatic binding free energy by using the Linear Interaction Energy (LIE) method. The results showed that the electrostatic binding free energy are correlated with values of constant inhibition (r2 = 0.97).Thus, the model obtained here could contribute to future studies of this important system and, therefore, eventually facilitate development of tyrosinase inhibitors. PMID:25004069

  11. Identification of a D-amino acid decapeptide HIV-1 entry inhibitor

    SciTech Connect

    Boggiano, Cesar; Jiang Shibo; Lu Hong; Zhao Qian; Liu Shuwen; Binley, James; Blondelle, Sylvie E. . E-mail: sylvieb@burnham.org

    2006-09-08

    Entry of human immunodeficiency virus type 1 (HIV-1) virion into host cells involves three major steps, each being a potential target for the development of entry inhibitors: gp120 binding to CD4, gp120-CD4 complex interacting with a coreceptor, and gp41 refolding to form a six-helix bundle. Using a D-amino acid decapeptide combinatorial library, we identified peptide DC13 as having potent HIV-1 fusion inhibitory activity, and effectively inhibiting infection by several laboratory-adapted and primary HIV-1 strains. While DC13 did not block binding of gp120 to CD4, nor disrupt the gp41 six-helix bundle formation, it effectively blocked the binding of an anti-CXCR4 monoclonal antibody and chemokine SDF-1{alpha} to CXCR4-expressing cells. However, because R5-using primary viruses were also neutralized, the antiviral activity of DC13 implies additional mode(s) of action. These results suggest that DC13 is a useful HIV-1 coreceptor antagonist for CXCR4 and, due to its biostability and simplicity, may be of value for developing a new class of HIV-1 entry inhibitors.

  12. Effect of free nitrous acid as inhibitors on nitrate reduction by a biological nutrient removal sludge.

    PubMed

    Ma, Juan; Yang, Qing; Wang, Shuying; Wang, Li; Takigawa, Akio; Peng, Yongzhen

    2010-03-15

    Nitrite has been commonly thought to have a broad inhibitory effect on bacterial metabolism. Little is known about the impact of nitrite on nitrate reduction with pH considered as an important factor. This study investigates the nitrite inhibition on nitrate reduction during denitrification under various pH conditions by using a biological nutrient removal (BNR) sludge. The results showed that nitrate reduction performance had a much stronger relationship with the free nitrous acid (FNA) than that of nitrite concentration, implying that FNA, rather than nitrite, is likely the real inhibitor on nitrate reduction. The nitrate reduction activity of the biomass was observed to be inhibited about 60% in the range of 0.01-0.025 mg HNO(2)-N/L and was totally inhibited when FNA level was greater than the threshold concentration (0.2mg HNO(2)-N/L). Moreover, the recovery rate from inhibitory effect was found to be dependent much more strongly on the concentration of FNA, of which the biomass was exposed to during the inhibition period, than on the duration of the inhibition and the feeding mode of inhibitor. It was also found that nitrite reduction was significantly inhibited by FNA and the nitrite reduction rate was linear to nitrate reduction rate due to the inhibitory mechanism under which FNA may react with the enzymes involved in the denitrification process. PMID:19910113

  13. Coexpression of Tyrosine Hydroxylase, GTP Cyclohydrolase I, Aromatic Amino Acid Decarboxylase, and Vesicular Monoamine Transporter 2 from a Helper Virus-Free Herpes Simplex Virus Type 1 Vector Supports High-Level, Long-Term Biochemical and Behavioral Correction of a Rat Model of Parkinson’s Disease

    PubMed Central

    SUN, MEI; KONG, LINGXIN; WANG, XIAODAN; HOLMES, COURTNEY; GAO, QINGSHENG; ZHANG, GUO-RONG; PFEILSCHIFTER, JOSEF; GOLDSTEIN, DAVID S.; GELLER, ALFRED I.

    2006-01-01

    Parkinson’s disease is due to the selective loss of nigrostriatal dopaminergic neurons. Consequently, many therapeutic strategies have focused on restoring striatal dopamine levels, including direct gene transfer to striatal cells, using viral vectors that express specific dopamine biosynthetic enzymes. The central hypothesis of this study is that coexpression of four dopamine biosynthetic and transporter genes in striatal neurons can support the efficient production and regulated, vesicular release of dopamine: tyrosine hydroxylase (TH) converts tyrosine to l-3,4-dihydroxyphenylalanine (l -DOPA), GTP cyclohydrolase I (GTP CH I) is the rate-limiting enzyme in the biosynthesis of the cofactor for TH, aromatic amino acid decarboxylase (AADC) converts l -DOPA to dopamine, and a vesicular monoamine transporter (VMAT-2) transports dopamine into synaptic vesicles, thereby supporting regulated, vesicular release of dopamine and relieving feedback inhibition of TH by dopamine. Helper virus-free herpes simplex virus type 1 vectors that coexpress the three dopamine biosynthetic enzymes (TH, GTP CH I, and AADC; 3-gene-vector) or these three dopamine biosynthetic enzymes and the vesicular monoamine transporter (TH, GTP CH I, AADC, and VMAT-2; 4-gene-vector) were compared. Both vectors supported production of dopamine in cultured fibroblasts. These vectors were microinjected into the striatum of 6-hydroxydopamine-lesioned rats. These vectors carry a modified neurofilament gene promoter, and γ-aminobutyric acid (GABA)-ergic neuron-specific gene expression was maintained for 14 months after gene transfer. The 4-gene-vector supported higher levels of correction of apomorphine-induced rotational behavior than did the 3-gene-vector, and this correction was maintained for 6 months. Proximal to the injection sites, the 4-gene-vector, but not the 3-gene-vector, supported extracellular levels of dopamine and dihydroxyphenylacetic acid (DOPAC) that were similar to those observed in

  14. Dopa decarboxylase activity of the living human brain

    SciTech Connect

    Gjedde, A.; Reith, J.; Dyve, S.; Leger, G.; Guttman, M.; Diksic, M.; Evans, A.; Kuwabara, H. )

    1991-04-01

    Monoaminergic neurons use dopa decarboxylase to form dopamine from L-3,4-dihydroxyphenylalanine (L-dopa). We measured regional dopa decarboxylase activity in brains of six healthy volunteers with 6-({sup 18}F)fluoro-L-dopa and positron emission tomography. We calculated the enzyme activity, relative to its Km, with a kinetic model that yielded the relative rate of conversion of 6-({sup 18}F)fluoro-L-dopa to ({sup 18}F)fluorodopamine. Regional values of relative dopa decarboxylase activity ranged from nil in occipital cortex to 1.9 h-1 in caudate nucleus and putamen, in agreement with values obtained in vitro.

  15. Structural basis for 18-β-glycyrrhetinic acid as a novel non-GSH analog glyoxalase I inhibitor

    PubMed Central

    Zhang, Hong; Huang, Qiang; Zhai, Jing; Zhao, Yi-ning; Zhang, Li-ping; Chen, Yun-yun; Zhang, Ren-wei; Li, Qing; Hu, Xiao-peng

    2015-01-01

    Aim: Glyoxalase I (GLOI), a glutathione (GSH)-dependent enzyme, is overexpressed in tumor cells and related to multi-drug resistance in chemotherapy, making GLOI inhibitors as potential anti-tumor agents. But the most studied GSH analogs exhibit poor pharmacokinetic properties. The aim of this study was to discover novel non-GSH analog GLOI inhibitors and analyze their binding mechanisms. Methods: Mouse GLOI (mGLOI) was expressed in BL21 (DE3) pLysS after induction with isopropyl-β-D-1-thiogalactopyranoside and purified using AKTA FPLC system. An in vitro mGLOI enzyme assay was used to screen a small pool of compounds containing carboxyl groups. Crystal structure of the mGLOI-inhibitor complex was determined at 2.3 Å resolution. Molecular docking study was performed using Discovery Studio 2.5 software package. Results: A natural compound 18-β-glycyrrhetinic acid (GA) and its derivative carbenoxolone were identified as potent competitive non-GSH analog mGLOI inhibitors with Ki values of 0.29 μmol/L and 0.93 μmol/L, respectively. Four pentacyclic triterpenes (ursolic acid, oleanolic acid, betulic acid and tripterine) showed weak activities (mGLOI inhibition ratio <25% at 10 μmol/L) and other three (maslinic acid, corosolic acid and madecassic acid) were inactive. The crystal structure of the mGLOI-GA complex showed that the carboxyl group of GA mimicked the γ-glutamyl residue of GSH by hydrogen bonding to the glutamyl sites (residues Arg38B, Asn104B and Arg123A) in the GSH binding site of mGLOI. The extensive van der Waals interactions between GA and the surrounding residues also contributed greatly to the binding of GA and mGLOI. Conclusion: This work demonstrates a carboxyl group to be an important functional feature of non-GSH analog GLOI inhibitors. PMID:26279158

  16. Four Amino Acid Changes in HIV-2 Protease Confer Class-Wide Sensitivity to Protease Inhibitors

    PubMed Central

    Smith, Robert A.; Gottlieb, Geoffrey S.

    2015-01-01

    ABSTRACT Protease is essential for retroviral replication, and protease inhibitors (PI) are important for treating HIV infection. HIV-2 exhibits intrinsic resistance to most FDA-approved HIV-1 PI, retaining clinically useful susceptibility only to lopinavir, darunavir, and saquinavir. The mechanisms for this resistance are unclear; although HIV-1 and HIV-2 proteases share just 38 to 49% sequence identity, all critical structural features of proteases are conserved. Structural studies have implicated four amino acids in the ligand-binding pocket (positions 32, 47, 76, and 82). We constructed HIV-2ROD9 molecular clones encoding the corresponding wild-type HIV-1 amino acids (I32V, V47I, M76L, and I82V) either individually or together (clone PRΔ4) and compared the phenotypic sensitivities (50% effective concentration [EC50]) of mutant and wild-type viruses to nine FDA-approved PI. Single amino acid replacements I32V, V47I, and M76L increased the susceptibility of HIV-2 to multiple PI, but no single change conferred class-wide sensitivity. In contrast, clone PRΔ4 showed PI susceptibility equivalent to or greater than that of HIV-1 for all PI. We also compared crystallographic structures of wild-type HIV-1 and HIV-2 proteases complexed with amprenavir and darunavir to models of the PRΔ4 enzyme. These models suggest that the amprenavir sensitivity of PRΔ4 is attributable to stabilizing enzyme-inhibitor interactions in the P2 and P2′ pockets of the protease dimer. Together, our results show that the combination of four amino acid changes in HIV-2 protease confer a pattern of PI susceptibility comparable to that of HIV-1, providing a structural rationale for intrinsic HIV-2 PI resistance and resolving long-standing questions regarding the determinants of differential PI susceptibility in HIV-1 and HIV-2. IMPORTANCE Proteases are essential for retroviral replication, and HIV-1 and HIV-2 proteases share a great deal of structural similarity. However, only three of nine

  17. Antibacterial drugs as corrosion inhibitors for bronze surfaces in acidic solutions

    NASA Astrophysics Data System (ADS)

    Rotaru, Ileana; Varvara, Simona; Gaina, Luiza; Muresan, Liana Maria

    2014-12-01

    The present study is aiming to investigate the effect of four antibiotics (amoxicillin, ciprofloxacin, doxycycline and streptomycin,) belonging to different classes of antibacterial drugs on bronze corrosion in a solution simulating an acid rain (pH 4). Due to their ability to form protective films on the metal surface, the tested antibiotics act as corrosion inhibitors for bronze. The antibiotics were tested at various concentrations in order to determine the optimal concentration range for the best corrosion inhibiting effect. In evaluating the inhibition efficiency, polarization curves, electrochemical impedance spectroscopy, SEM and XPS measurements were used. Moreover, a correlation between the inhibition efficiency of some antibacterial drugs and certain molecular parameters was determined by quantum chemical computations. Parameters like energies EHOMO and ELUMO and HOMO-LUMO energy gap were used for correlation with the corrosion data.

  18. Pistagremic acid, a novel β-secretase enzyme (BACE1) inhibitor from Pistacia integerrima Stewart.

    PubMed

    Rauf, Abdur; Uddin, Ghias; Khan, Ajmal; Siddiqui, Bina S; Arfan, Mohammad; Dalvandi, Kourosh; Ben Hadda, Taibi

    2015-01-01

    A new triterpenic compound named pistagremic acid (PA) was once again isolated from Pistaciaintegerrima. The β-secretase inhibition study was carried out. Compound PA was found significantly active against β-secretase enzyme (BACE1) with IC50 value of 350 ± 2 nM in comparison to the standard inhibitors [Asn670, Sta671, Val672]-amyloid-β/A4 precursor protein 770 fragment 662-675 (IC50 = 290.71 ± 1 nM). The selectivity of this compound was also evaluated against the acetylcholinesterase and butyrylcholinesterase enzymes. Interestingly compound PA was found to be inactive against them and showed selectivity towards β-secretase enzyme (BACE1). PMID:25588845

  19. Pyrrolidinobenzoic Acid Inhibitors of Influenza Virus Neuraminidase: the Hydrophobic Side Chain Influences Type A Subtype Selectivity

    PubMed Central

    Li, Yanwu; Silamkoti, Arundutt; Kolavi, Gundurao; Mou, Liyuan; Gulati, Shelly; Air, Gillian M.

    2012-01-01

    Neuraminidase (NA) plays a critical role in the life cycle of influenza virus and is a target for new therapeutic agents. A series of influenza neuraminidase inhibitors with the pyrrolidinobenzoic acid scaffold containing lipophilic side chains at the C3 position have been synthesized and evaluated for influenza neuraminidase inhibitory activity. The size and geometry of the C3 side chains have been modified in order to investigate structure-activity relationships. The results indicated that size and geometry of the C3-side chain are important for selectivity of inhibition against N1 vs N2 NA, important type A influenza variants that infect man, including the highly lethal avian influenza. PMID:22677529

  20. Pyrrolidinobenzoic acid inhibitors of influenza virus neuraminidase: the hydrophobic side chain influences type A subtype selectivity.

    PubMed

    Li, Yanwu; Silamkoti, Arundutt; Kolavi, Gundurao; Mou, Liyuan; Gulati, Shelly; Air, Gillian M; Brouillette, Wayne J

    2012-07-15

    Neuraminidase (NA) plays a critical role in the life cycle of influenza virus and is a target for new therapeutic agents. A series of influenza neuraminidase inhibitors with the pyrrolidinobenzoic acid scaffold containing lipophilic side chains at the C3 position have been synthesized and evaluated for influenza neuraminidase inhibitory activity. The size and geometry of the C3 side chains have been modified in order to investigate structure-activity relationships. The results indicated that size and geometry of the C3-side chain are important for selectivity of inhibition against N1 versus N2 NA, important type A influenza variants that infect man, including the highly lethal avian influenza. PMID:22677529

  1. Cloning of aldB, which encodes alpha-acetolactate decarboxylase, an exoenzyme from Bacillus brevis.

    PubMed Central

    Diderichsen, B; Wedsted, U; Hedegaard, L; Jensen, B R; Sjøholm, C

    1990-01-01

    A gene for alpha-acetolactate decarboxylase (ALDC) was cloned from Bacillus brevis in Escherichia coli and in Bacillus subtilis. The 1.3-kilobase-pair nucleotide sequence of the gene, aldB, encoding ALDC and its flanking regions was determined. An open reading frame of 285 amino acids included a typical N-terminal signal peptide of 24 or 27 amino acids. A B. subtilis strain harboring the aldB gene on a recombinant plasmid processed and secreted ALDC. In contrast, a similar enzyme from Enterobacter aerogenes is intracellular. Images PMID:2198252

  2. Antinociceptive effects of the N-acylethanolamine acid amidase inhibitor ARN077 in rodent pain models.

    PubMed

    Sasso, Oscar; Moreno-Sanz, Guillermo; Martucci, Cataldo; Realini, Natalia; Dionisi, Mauro; Mengatto, Luisa; Duranti, Andrea; Tarozzo, Glauco; Tarzia, Giorgio; Mor, Marco; Bertorelli, Rosalia; Reggiani, Angelo; Piomelli, Daniele

    2013-03-01

    Fatty acid ethanolamides (FAEs), which include palmitoylethanolamide (PEA) and oleoylethanolamide (OEA), are endogenous agonists of peroxisome proliferator-activated receptor-α (PPAR-α) and important regulators of the inflammatory response. They are degraded in macrophages by the lysosomal cysteine amidase, N-acylethanolamine acid amidase (NAAA). Previous studies have shown that pharmacological inhibition of NAAA activity suppresses macrophage activation in vitro and causes marked anti-inflammatory effects in vivo, which is suggestive of a role for NAAA in the control of inflammation. It is still unknown, however, whether NAAA-mediated FAE deactivation might regulate pain signaling. The present study examined the effects of ARN077, a potent and selective NAAA inhibitor recently disclosed by our group, in rodent models of hyperalgesia and allodynia caused by inflammation or nerve damage. Topical administration of ARN077 attenuated, in a dose-dependent manner, heat hyperalgesia and mechanical allodynia elicited in mice by carrageenan injection or sciatic nerve ligation. The antinociceptive effects of ARN077 were prevented by the selective PPAR-α antagonist GW6471 and did not occur in PPAR-α-deficient mice. Furthermore, topical ARN077 reversed the allodynia caused by ultraviolet B radiation in rats, and this effect was blocked by pretreatment with GW6471. Sciatic nerve ligation or application of the proinflammatory phorbol ester 12-O-tetradecanoylphorbol 13-acetate decreased FAE levels in sciatic nerve and skin tissue, respectively. ARN077 reversed these biochemical effects. The results identify ARN077 as a potent inhibitor of intracellular NAAA activity, which is active in vivo by topical administration. The findings further suggest that NAAA regulates peripheral pain initiation by interrupting endogenous FAE signaling at PPAR-α. PMID:23218523

  3. ANTINOCICEPTIVE EFFECTS OF THE N-ACYLETHANOLAMINE ACID AMIDASE INHIBITOR ARN077 IN RODENT PAIN MODELS

    PubMed Central

    Sasso, Oscar; Moreno-Sanz, Guillermo; Martucci, Cataldo; Realini, Natalia; Dionisi, Mauro; Mengatto, Luisa; Duranti, Andrea; Tarozzo, Glauco; Tarzia, Giorgio; Mor, Marco; Bertorelli, Rosalia; Reggiani, Angelo; Piomelli, Daniele

    2013-01-01

    Fatty acid ethanolamides (FAEs), which include palmitoylethanolamide (PEA) and oleoylethanolamide (OEA), are endogenous agonists of peroxisome proliferator-activated receptor-α (PPAR-α) and important regulators of the inflammatory response. They are degraded in macrophages by the lysosomal cysteine amidase, N-acylethanolamine acid amidase (NAAA). Previous studies have shown that pharmacological inhibition of NAAA activity suppresses macrophage activation in vitro and causes marked anti-inflammatory effects in vivo, which is suggestive of a role for NAAA in the control of inflammation. It is still unknown, however, whether NAAA-mediated FAE deactivation might regulate pain signaling. In the present study, we examined the effects of ARN077, a potent and selective NAAA inhibitor recently disclosed by our group, in rodent models of hyperalgesia and allodynia caused by inflammation or nerve damage. Topical administration of ARN077 attenuated, in a dose-dependent manner, heat hyperalgesia and mechanical allodynia elicited in mice by carrageenan injection or sciatic nerve ligation. The anti-nociceptive effects of ARN077 were prevented by the selective PPAR-α antagonist GW6471 and did not occur in PPAR-α-deficient mice. Furthermore, topical ARN077 reversed the allodynia caused by ultraviolet B-radiation in rats, and this effect was blocked by pretreatment with GW6471. Sciatic nerve ligation or application of the pro-inflammatory phorbol ester 12-O-tetradecanoylphorbol 13-acetate (TPA) decreased FAE levels in sciatic nerve and skin tissue, respectively. ARN077 reversed these biochemical effects. The results identify ARN077 as a potent inhibitor of intracellular NAAA activity, which is active in vivo by topical administration. The findings further suggest that NAAA regulates peripheral pain initiation by interrupting endogenous FAE signaling at PPAR-α. PMID:23218523

  4. EPR Spin Trapping of an Oxalate-Derived Free Radical in the Oxalate Decarboxylase Reaction

    PubMed Central

    Imaram, Witcha; Saylor, Benjamin T.; Centonze, Christopher P.; Richards, Nigel G. J.; Angerhofer, Alexander

    2011-01-01

    EPR spin trapping experiments on bacterial oxalate decarboxylase from Bacillus subtilis under turn-over conditions are described. The use of doubly 13C-labeled oxalate leads to a characteristic splitting of the observed radical adducts using the spin trap N-tert-butyl-α-phenylnitrone linking them directly to the substrate. The radical was identified as the carbon dioxide radical anion which is a key intermediate in the hypothetical reaction mechanism of both decarboxylase and oxidase activities. X-ray crystallography had identified a flexible loop, SENS161-4, which acts as a lid to the putative active site. Site directed mutagenesis of the hinge amino acids, S161 and T165 was explored and showed increased radical trapping yields compared to the wild type. In particular, T165V shows approximately ten times higher radical yields while at the same time its decarboxylase activity was reduced by about a factor of ten. This mutant lacks a critical H-bond between T165 and R92 resulting in compromised control over its radical chemistry allowing the radical intermediate to leak into the surrounding solution. PMID:21277974

  5. Perturbation of the Monomer-Monomer Interfaces of the Benzoylformate Decarboxylase Tetramer

    SciTech Connect

    Andrews, Forest H.; Rogers, Megan P.; Paul, Lake N.; McLeish, Michael J.

    2014-08-14

    The X-ray structure of benzoylformate decarboxylase (BFDC) from Pseudomonas putida ATCC 12633 shows it to be a tetramer. This was believed to be typical of all thiamin diphosphate-dependent decarboxylases until recently when the structure of KdcA, a branched-chain 2-keto acid decarboxylase from Lactococcus lactis, showed it to be a homodimer. This lent credence to earlier unfolding experiments on pyruvate decarboxylase from Saccharomyces cerevisiae that indicated that it might be active as a dimer. To investigate this possibility in BFDC, we sought to shift the equilibrium toward dimer formation. Point mutations were made in the noncatalytic monomer–monomer interfaces, but these had a minimal effect on both tetramer formation and catalytic activity. Subsequently, the R141E/Y288A/A306F variant was shown by analytical ultracentrifugation to be partially dimeric. It was also found to be catalytically inactive. Further experiments revealed that just two mutations, R141E and A306F, were sufficient to markedly alter the dimer–tetramer equilibrium and to provide an ~450-fold decrease in kcat. Equilibrium denaturation studies suggested that the residual activity was possibly due to the presence of residual tetramer. The structures of the R141E and A306F variants, determined to <1.5 Å resolution, hinted that disruption of the monomer interfaces will be accompanied by movement of a loop containing Leu109 and Leu110. As these residues contribute to the hydrophobicity of the active site and the correct positioning of the substrate, it seems that tetramer formation may well be critical to the catalytic activity of BFDC.

  6. Perturbation of the Monomer–Monomer Interfaces of the Benzoylformate Decarboxylase Tetramer

    PubMed Central

    2015-01-01

    The X-ray structure of benzoylformate decarboxylase (BFDC) from Pseudomonas putida ATCC 12633 shows it to be a tetramer. This was believed to be typical of all thiamin diphosphate-dependent decarboxylases until recently when the structure of KdcA, a branched-chain 2-keto acid decarboxylase from Lactococcus lactis, showed it to be a homodimer. This lent credence to earlier unfolding experiments on pyruvate decarboxylase from Saccharomyces cerevisiae that indicated that it might be active as a dimer. To investigate this possibility in BFDC, we sought to shift the equilibrium toward dimer formation. Point mutations were made in the noncatalytic monomer–monomer interfaces, but these had a minimal effect on both tetramer formation and catalytic activity. Subsequently, the R141E/Y288A/A306F variant was shown by analytical ultracentrifugation to be partially dimeric. It was also found to be catalytically inactive. Further experiments revealed that just two mutations, R141E and A306F, were sufficient to markedly alter the dimer–tetramer equilibrium and to provide an ∼450-fold decrease in kcat. Equilibrium denaturation studies suggested that the residual activity was possibly due to the presence of residual tetramer. The structures of the R141E and A306F variants, determined to <1.5 Å resolution, hinted that disruption of the monomer interfaces will be accompanied by movement of a loop containing Leu109 and Leu110. As these residues contribute to the hydrophobicity of the active site and the correct positioning of the substrate, it seems that tetramer formation may well be critical to the catalytic activity of BFDC. PMID:24956165

  7. Physical Nature of Fatty Acid Amide Hydrolase Interactions with Its Inhibitors: Testing a Simple Nonempirical Scoring Model.

    PubMed

    Giedroyć-Piasecka, Wiktoria; Dyguda-Kazimierowicz, Edyta; Beker, Wiktor; Mor, Marco; Lodola, Alessio; Sokalski, W Andrzej

    2014-12-26

    Fatty acid amide hydrolase (FAAH) is an enzyme responsible for the deactivating hydrolysis of fatty acid ethanolamide neuromodulators. FAAH inhibitors have gained considerable interest due to their possible application in the treatment of anxiety, inflammation, and pain. In the context of inhibitor design, the availability of reliable computational tools for predicting binding affinity is still a challenging task, and it is now well understood that empirical scoring functions have several limitations that in principle could be overcome by quantum mechanics. Herein, systematic ab initio analyses of FAAH interactions with a series of inhibitors belonging to the class of the N-alkylcarbamic acid aryl esters have been performed. In contrast to our earlier studies of other classes of enzyme-inhibitor complexes, reasonable correlation with experimental results required us to consider correlation effects along with electrostatic term. Therefore, the simplest comprehensive nonempirical model allowing for qualitative predictions of binding affinities for FAAH ligands consists of electrostatic multipole and second-order dispersion terms. Such a model has been validated against the relative stabilities of the benchmark S66 set of biomolecular complexes. As it does not involve parameters fitted to experimentally derived data, this model offers a unique opportunity for generally applicable inhibitor design and virtual screening. PMID:25420234

  8. Binding of α,α-Disubstituted Amino Acids to Arginase Suggests New Avenues for Inhibitor Design1

    PubMed Central

    Ilies, Monica; Di Costanzo, Luigi; Dowling, Daniel P.; Thorn, Katherine J.; Christianson, David W.

    2011-01-01

    Arginase is a binuclear manganese metalloenzyme that hydrolyzes L-arginine to form L-ornithine and urea, and aberrant arginase activity is implicated in various diseases such as erectile dysfunction, asthma, atherosclerosis, and cerebral malaria. Accordingly, arginase inhibitors may be therapeutically useful. Continuing our efforts to expand the chemical space of arginase inhibitor design, and inspired by the binding of 2-(difluoromethyl)-L-ornithine to human arginase I, we now report the first study of the binding of α,α-disubstituted amino acids to arginase. Specifically, we report the design, synthesis, and assay of racemic 2-amino-6-borono-2- methylhexanoic acid and racemic 2-amino-6-borono-2-(difluoromethyl)hexanoic acid. X-ray crystal structures of human arginase I and Plasmodium falciparum arginase complexed with these inhibitors reveal the exclusive binding of the L-stereoisomer; the additional α-substituent of each inhibitor is readily accommodated and makes new intermolecular interactions in the outer active site of each enzyme. Therefore, this work highlights a new region of the protein surface that can be targeted for additional affinity interactions, as well as the first comparative structural insights on inhibitor discrimination between a human and a parasitic arginase. PMID:21728378

  9. A human fatty acid synthase inhibitor binds β-ketoacyl reductase in the keto-substrate site.

    PubMed

    Hardwicke, Mary Ann; Rendina, Alan R; Williams, Shawn P; Moore, Michael L; Wang, Liping; Krueger, Julie A; Plant, Ramona N; Totoritis, Rachel D; Zhang, Guofeng; Briand, Jacques; Burkhart, William A; Brown, Kristin K; Parrish, Cynthia A

    2014-09-01

    Human fatty acid synthase (hFAS) is a complex, multifunctional enzyme that is solely responsible for the de novo synthesis of long chain fatty acids. hFAS is highly expressed in a number of cancers, with low expression observed in most normal tissues. Although normal tissues tend to obtain fatty acids from the diet, tumor tissues rely on de novo fatty acid synthesis, making hFAS an attractive metabolic target for the treatment of cancer. We describe here the identification of GSK2194069, a potent and specific inhibitor of the β-ketoacyl reductase (KR) activity of hFAS; the characterization of its enzymatic and cellular mechanism of action; and its inhibition of human tumor cell growth. We also present the design of a new protein construct suitable for crystallography, which resulted in what is to our knowledge the first co-crystal structure of the human KR domain and includes a bound inhibitor. PMID:25086508

  10. Induction of α-Amylase Inhibitor Synthesis in Barley Embryos and Young Seedlings by Abscisic Acid and Dehydration Stress 1

    PubMed Central

    Robertson, Masumi; Walker-Simmons, M.; Munro, Doug; Hill, Robert D.

    1989-01-01

    An endogenous α-amylase inhibitor was found to be synthesized in embryos of developing barley grain (Hordeum vulgare cv Bonanza). Accumulation of this protein occurred late in development (stage IV), at the same time that endogenous abscisic acid (ABA) showed a large increase. The inhibitor could be induced up to 23-fold in isolated immature embryos (stage III) by culture in ABA. Precocious germination was also blocked in stage III embryos by ABA. Dehydration stress on the isolated immature embryos also induced higher levels of the inhibitor and ABA. An even greater response to dehydration stress was observed in young seedlings, where inhibitor content increased 20-fold and ABA increased 80-fold during water stress. The high degree of correlation between ABA and inhibitor contents in in situ embryos, dehydrated embryos and young seedlings, as well as the increase in inhibitor caused by exogenously applied ABA to isolated embryos, suggests that increased α-amylase inhibitor synthesis in response to dehydration stress is mediated by ABA. PMID:16667035

  11. In silico modification of suberoylanilide hydroxamic acid (SAHA) as potential inhibitor for class II histone deacetylase (HDAC)

    PubMed Central

    2011-01-01

    Background The cervical cancer is the second most prevalent cancer for the woman in the world. It is caused by the oncogenic human papilloma virus (HPV). The inhibition activity of histone deacetylase (HDAC) is a potential strategy for cancer therapy. Suberoylanilide hydroxamic acid (SAHA) is widely known as a low toxicity HDAC inhibitor. This research presents in silico SAHA modification by utilizing triazole, in order to obtain a better inhibitor. We conducted docking of the SAHA inhibitor and 12 modified versions to six class II HDAC enzymes, and then proceeded with drug scanning of each one of them. Results The docking results show that the 12 modified inhibitors have much better binding affinity and inhibition potential than SAHA. Based on drug scan analysis, six of the modified inhibitors have robust pharmacological attributes, as revealed by drug likeness, drug score, oral bioavailability, and toxicity levels. Conclusions The binding affinity, free energy and drug scan screening of the best inhibitors have shown that 1c and 2c modified inhibitors are the best ones to inhibit class II HDAC. PMID:22373132

  12. Microwave-Assisted Syntheses of Amino Acid Ester Substituted Benzoic Acid Amides: Potential Inhibitors of Human CD81-Receptor HCV-E2 Interaction.

    PubMed

    Holzer, Marcel; Ziegler, Sigrid; Kronenberger, Bernd; Klein, Christian D; Hartmann, Rolf W

    2008-01-01

    Results from our group showed benzyl salicylate to be a moderate inhibitor of the CD81-LEL-HCV-E2 interaction. To increase the biological activity, heterocyclic substituted benzoic acids were coupled to amino acid esters via microwave assisted DCC-reaction. The prepared compounds were tested for their inhibitory potency by means of a fluorescence labeled antibody assay system using HUH7.5 cells. PMID:19662141

  13. Structure-guided Discovery of Phenyl diketo-acids as Potent Inhibitors of M. tuberculosis Malate Synthase

    PubMed Central

    Krieger, Inna V.; Freundlich, Joel S.; Gawandi, Vijay B.; Roberts, Justin P.; Gawandi, Vidyadhar B.; Sun, Qingan; Owen, Joshua L.; Fraile, Maria T.; Huss, Sofia I.; Lavandera, Jose-Luis; Ioerger, Thomas R.; Sacchettini, James C.

    2012-01-01

    Summary The glyoxylate shunt plays an important role in fatty-acid metabolism, and has been shown to be critical to survival of several pathogens involved in chronic infections. For Mycobacterium tuberculosis (Mtb), a strain with a defective glyoxylate shunt was previously shown to be unable to establish infection in a mouse model. We report the development of novel phenyl-diketo acid (PDKA) inhibitors of malate synthase (GlcB), one of two glyoxylate shunt enzymes, using structure-based methods. PDKA inhibitors were active against Mtb grown on acetate, and over-expression of GlcB ameliorated this inhibition. Crystal structures of complexes of GlcB with PDKA inhibitors were used to guide optimization of potency. A selected PDKA compound demonstrated efficacy in a mouse model of tuberculosis. The discovery of these PDKA derivatives provides chemical validation of GlcB as an attractive target for tuberculosis therapeutics. PMID:23261599

  14. A kinetic analysis of Drosophila melanogaster dopa decarboxylase.

    PubMed

    Black, B C; Smarrelli, J

    1986-03-01

    The kinetic mechanism of dopa decarboxylase (3,4-dihydroxy-L-phenylalanine carboxy-lyase, EC 4.1.1.28) was investigated in Drosophila melanogaster. Based on initial velocity and product inhibition studies, an ordered reaction is proposed for dopa decarboxylase. This kinetic mechanism is interpreted in the context of measured enzyme activities and the catecholamine pools in Drosophila. The 1(2)amd gene is immediately adjacent to the gene coding for dopa decarboxylase (Ddc) and determines hypersensitivity to alpha-methyldopa in Drosophila. Dopa decarboxylase does not decarboxylate alpha-methyldopa and hence does not generate a toxic product capable of inhibiting 1(2)amd gene function. We propose that the 1(2)amd gene is involved with an unknown catecholamine pathway involving dopa but not dopamine. PMID:3081033

  15. Keto-isovalerate decarboxylase enzymes and methods of use thereof

    DOEpatents

    McElvain, Jessica; O'Keefe, Daniel P.; Paul, Brian James; Payne, Mark S.; Rothman, Steven Cary; He, Hongxian

    2016-01-19

    Provided herein are polypeptides and polynucleotides encoding such polypeptides which have ketoisovalerate decarboxylase activity. Also provided are recombinant host cells comprising such polypeptides and polynucleotides and methods of use thereof.

  16. A colorimetric and near-infrared fluorescent probe with high sensitivity and selectivity for acid phosphatase and inhibitor screening.

    PubMed

    Xu, Yongqian; Li, Benhao; Xiao, Liangliang; Ouyang, Jia; Sun, Shiguo; Pang, Yi

    2014-08-14

    A dual-channel including a colorimetric and fluorescent probe based on the aggregation-caused quenching (ACQ) and enzymolysis approach has been presented to screen acid phosphatase (ACP) and its inhibitor. Moreover, the ACP activity was determined by real time assay. PMID:24957006

  17. Urolithin as a converging scaffold linking ellagic acid and coumarin analogues: design of potent protein kinase CK2 inhibitors.

    PubMed

    Cozza, Giorgio; Gianoncelli, Alessandra; Bonvini, Paolo; Zorzi, Elisa; Pasquale, Riccardo; Rosolen, Angelo; Pinna, Lorenzo A; Meggio, Flavio; Zagotto, Giuseppe; Moro, Stefano

    2011-12-01

    Casein kinase 2 (CK2) is a ubiquitous, essential, and highly pleiotropic protein kinase; its abnormally high constitutive activity is suspected to underlie its pathogenic potential in neoplasia and other relevant diseases. Previously, using different in silico screening approaches, two potent and selective CK2 inhibitors were identified by our group: ellagic acid, a naturally occurring tannic acid derivative (K(i)=20 nM) and 3,8-dibromo-7-hydroxy-4-methylchromen-2-one (DBC, K(i)=60 nM). Comparing the crystallographic binding modes of both ellagic acid and DBC, an X-ray structure-driven merging approach was taken to design novel CK2 inhibitors with improved target affinity. A urolithin moiety is proposed as a possible bridging scaffold between the two known CK2 inhibitors, ellagic acid and DBC. Optimization of urolithin A as the bridging moiety led to the identification of 4-bromo-3,8-dihydroxy-benzo[c]chromen-6-one as a novel, potent and selective CK2 inhibitor, which shows a K(i) value of 7 nM against the protein kinase, representing a significant improvement in affinity for the target compared with the two parent fragments. PMID:21972104

  18. Control of gastric acid secretion. Histamine H2-receptor antagonists and H+K(+)-ATPase inhibitors.

    PubMed

    Shamburek, R D; Schubert, M L

    1992-09-01

    Gastric acid secretion is regulated by an intricate interplay of neural (acetylcholine), hormonal (gastrin), and paracrine (histamine, somatostatin) mechanisms. Receptors for each of these agents and the signal transduction pathways to which these receptors are coupled have been identified on the parietal cell. The stimulatory effect of acetylcholine and gastrin is mediated by an increase in cytosolic calcium, whereas that of histamine is mediated by activation of adenylate cyclase and generation of cAMP. Strong potentiation between histamine and either gastrin or acetylcholine reflects postreceptor interaction between the distinct pathways as well as the ability of acetylcholine and gastrin to release histamine from mucosal ECL cells. The inhibitory effects of somatostatin on acid secretion are mediated by receptors coupled by guanine nucleotide-binding proteins to inhibition of adenylate cyclase activity. All the pathways converge on and modulate the activity of the luminal enzyme, H+K(+)-ATPase, the proton pump of the parietal cell. Precise information on the mechanisms involved in gastric acid secretion has led to the development of potent drugs capable of inhibiting acid secretion. These include competitive antagonists that interact with stimulatory receptors (e.g., histamine H2-receptor antagonists) as well as noncompetitive inhibitors of H+K(+)-ATPase (e.g., omeprazole). The histamine H2-receptor antagonists (cimetidine, ranitidine, famotidine, and nizatidine) continue as first-line therapy for peptic ulcer disease and are effective in preventing relapse. Although they are generally well tolerated, histamine H2-receptor antagonists may cause untoward CNS, cardiac, and endocrine effects as well as interference with the absorption, metabolism, and elimination of various drugs. Omeprazole is a weak base that reaches the parietal cell through the bloodstream, diffuses through the cytoplasm, and becomes activated and trapped as a sulfenamide in the acidic

  19. Synthesis of all stereoisomers of 3-hydroxypipecolic acid and 3-hydroxy-4,5-dehydropipecolic acid and their evaluation as glycosidase inhibitors.

    PubMed

    Ohara, Chiaki; Takahashi, Ryouko; Miyagawa, Tatsunori; Yoshimura, Yuichi; Kato, Atsushi; Adachi, Isao; Takahata, Hiroki

    2008-03-15

    A highly practicable synthesis of both enantiomers of 3-hydroxypipecolic acid derivatives 1, 2, 3, 4 is described. Screening of these molecules for glycosidase inhibition has been examined. Compound 3 was shown to be a potent inhibitor of beta-N-acetylglucosaminidase as well as Escherichia coli beta-glucuronidase. PMID:18296050

  20. Structural studies on sweet taste inhibitors: lactisole, DL-2(4-methoxyphenoxy)-propanoic acid

    NASA Astrophysics Data System (ADS)

    Matholouthi, M.; Angiboust, J. F.; Kacurakova, M.; Hooft, R. W. W.; Kanters, J. A.; Kroon, J.

    1994-09-01

    Lactisole, DL-2-(4-methoxyphenoxy)-propanoic acid (HPMP) has the formula C 10O 4H 12, Mr = 196.20, and is monoclinic, C2/c. a = 34.944(5), b = 5.2146(14), c = 11.201(2) Å, β = 101.495(13)°, V = 2000.1(7) Å 3, Z = 8, Dx = 1.3031(5) mg m -3, λ(Mo Kα) = 0.71073 Å, μ = 0.9 cm -1, F(000) = 832, R = 0.0392 for 1468 unique observed diffractometer data ( I ⩾ 2.5σ( I)). In the molecule two planar fragments, the acetic acid group and the phenyl ring, are almost perpendicular (interplanar angle 80.4(1)°). The crystal structure is characterized by cyclic dimers formed by hydrogen bonds between carboxyl groups across centers of inversion. The sodium salt of lactisole, NaPMP, is also a selective inhibitor of the sweetness of sucrose and was studied in aqueous solution in order to elucidate the mechanism of sweet taste inhibition. Solution properties, FT-IR spectra and the effect of NaPMP on the structure of water as determined by Raman spectra in the region of the OH stretching vibration were investigated. The hydrophobicity of NaPMP together with the steric hindrance caused by this molecule at the entrance of the sweet taste receptor site are probably at the origin of its inhibitory effect.

  1. Pentapeptide Boronic Acid Inhibitors of Mycobacterium tuberculosis MycP1 Protease

    PubMed Central

    Frasinyuk, Mykhaylo S.; Kwiatkowski, Stefan; Wagner, Jonathan M.; Evans, Timothy J.; Reed, Robert W.; Korotkov, Konstantin V.; Watt, David S.

    2014-01-01

    Mycosin protease-1 (MycP1) cleaves ESX secretion-associated protein B (EspB) that is a virulence factor of Mycobacterium tuberculosis, and accommodates an octapeptide, AVKAASLG, as a short peptide substrate. Because peptidoboronic acids are known inhibitors of serine proteases, the synthesis and binding of a boronic acid analog of the pentapeptide cleavage product, AVKAA, was studied using MycP1 variants from M. thermoresistible (MycP1mth), M. smegmatis (MycP1msm) and M. tuberculosis (MycP1mtu). We synthesized the boropentapeptide, HAlaValLysAlaAlaB(OH)2 (1) and the analogous pinanediol PD-protected HAlaValLysAlaAlaBO2(PD) (2) using an Fmoc/Boc peptide strategy. The pinanediol boropentapeptide 2 displayed IC50 values 121.6±25.3 μM for MycP1mth, 93.2±37.3 μM for MycP1msm and 37.9±5.2 μM for MycP1mtu. Such relatively strong binding creates a chance for crystalizing the complex with 2 and finding the structure of the unknown MycP1 catalytic site that would potentially facilitate the development of new anti-tuberculosis drugs. PMID:24915878

  2. Novel route to chaetomellic acid A and analogues: serendipitous discovery of a more competent FTase inhibitor.

    PubMed

    Bellesia, Franco; Choi, Seoung-ryoung; Felluga, Fulvia; Fiscaletti, Giuliano; Ghelfi, Franco; Menziani, Maria Cristina; Parsons, Andrew F; Poulter, C Dale; Roncaglia, Fabrizio; Sabbatini, Massimo; Spinelli, Domenico

    2013-01-01

    A new practical route to chaetomellic acid A (ACA), based on the copper catalysed radical cyclization (RC) of (Z)-3-(2,2-dichloropropanoyl)-2-pentadecylidene-1,3-thiazinane, is described. Remarkably, the process entailed: (i) a one-pot preparation of the intermediate N-α-perchloroacyl-2-(Z)-alkyliden-1,3-thiazinanes starting from N-(3-hydroxypropyl)palmitamide, (ii) a two step smooth transformation of the RC products into ACA and (iii) only one intermediate chromatographic purification step. The method offers a versatile approach to the preparation of ACA analogues, through the synthesis of an intermediate maleic anhydride with a vinylic group at the end of the aliphatic tail, a function that can be transformed through a thiol-ene coupling. Serendipitously, the disodium salt of 2-(9-(butylthio)nonyl)-3-methylmaleic acid, that we prepared as a representative sulfurated ACA analogue, was a more competent FTase inhibitor than ACA. This behaviour was analysed by a molecular docking study. PMID:23182215

  3. Novel route to chaetomellic acid A and analogues: serendipitous discovery of a more competent FTase inhibitor

    PubMed Central

    Bellesia, Franco; Choi, Seoung-ryoung; Felluga, Fulvia; Fiscaletti, Giuliano; Ghelfi, Franco; Menziani, Maria Cristina; Parsons, Andrew F.; Poulter, C. Dale; Roncaglia, Fabrizio; Sabbatini, Massimo; Spinelli, Domenico

    2013-01-01

    A new practical route to chaetomellic acid A (ACA), based on the copper catalysed radical cyclization (RC) of (Z)-3-(2,2-dichloropropanoyl)-2-pentadecylidene-1,3-thiazinane, is described. Remarkably, the process entailed: i) a one-pot preparation of the intermediate N-α-perchloroacyl-2-(Z)-alkyliden-1,3-thiazinanes starting from N-(3-hydroxypropyl)palmitamide, ii) a two step smooth transformation of the RC products into ACA and iii) only one intermediate chromatographic purification step. The method offers a versatile approach to the preparation of ACA analogues, through the synthesis of an intermediate maleic anhydride with a vinylic group at the end of the aliphatic tail, a function that can be transformed through a thiol-ene coupling. Serendipitously, the disodium salt of 2-(9-(butylthio)nonyl)-3-methylmaleic acid, that we prepared as a representative sulfurated ACA analogue, was a more competent FTase inhibitor than ACA. This behaviour was analysed by a molecular docking study. PMID:23182215

  4. Two Distinctive Binding Modes of Endonuclease Inhibitors to the N-Terminal Region of Influenza Virus Polymerase Acidic Subunit.

    PubMed

    Fudo, Satoshi; Yamamoto, Norio; Nukaga, Michiyoshi; Odagiri, Takato; Tashiro, Masato; Hoshino, Tyuji

    2016-05-10

    Influenza viruses are global threat to humans, and the development of new antiviral agents are still demanded to prepare for pandemics and to overcome the emerging resistance to the current drugs. Influenza polymerase acidic protein N-terminal domain (PAN) has endonuclease activity and is one of the appropriate targets for novel antiviral agents. First, we performed X-ray cocrystal analysis on the complex structures of PAN with two endonuclease inhibitors. The protein crystallization and the inhibitor soaking were done at pH 5.8. The binding modes of the two inhibitors were different from a common binding mode previously reported for the other influenza virus endonuclease inhibitors. We additionally clarified the complex structures of PAN with the same two endonuclease inhibitors at pH 7.0. In one of the crystal structures, an additional inhibitor molecule, which chelated to the two metal ions in the active site, was observed. On the basis of the crystal structures at pH 7.0, we carried out 100 ns molecular dynamics (MD) simulations for both of the complexes. The analysis of simulation results suggested that the binding mode of each inhibitor to PAN was stable in spite of the partial deviation of the simulation structure from the crystal one. Furthermore, crystal structure analysis and MD simulation were performed for PAN in complex with an inhibitor, which was already reported to have a high compound potency for comparison. The findings on the presence of multiple binding sites at around the PAN substrate-binding pocket will provide a hint for enhancing the binding affinity of inhibitors. PMID:27088785

  5. Targeting ornithine decarboxylase in Myc-induced lymphomagenesis prevents tumor formation.

    PubMed

    Nilsson, Jonas A; Keller, Ulrich B; Baudino, Troy A; Yang, Chunying; Norton, Sara; Old, Jennifer A; Nilsson, Lisa M; Neale, Geoffrey; Kramer, Debora L; Porter, Carl W; Cleveland, John L

    2005-05-01

    Checkpoints that control Myc-mediated proliferation and apoptosis are bypassed during tumorigenesis. Genes encoding polyamine biosynthetic enzymes are overexpressed in B cells from E mu-Myc transgenic mice. Here, we report that disabling one of these Myc targets, Ornithine decarboxylase (Odc), abolishes Myc-induced suppression of the Cdk inhibitors p21(Cip1) and p27(Kip1), thereby impairing Myc's proliferative, but not apoptotic, response. Moreover, lymphoma development was markedly delayed in E mu-Myc;Odc(+/-) transgenic mice and in E mu-Myc mice treated with the Odc inhibitor difluoromethylornithine (DFMO). Strikingly, tumors ultimately arising in E mu-Myc;Odc(+/-) transgenics lacked deletions of Arf, suggesting that targeting Odc forces other routes of transformation. Therefore, Odc is a critical Myc transcription target that regulates checkpoints that guard against tumorigenesis and is an effective target for cancer chemoprevention. PMID:15894264

  6. Effects of alpha-amylase and its inhibitors on acid production from cooked starch by oral streptococci.

    PubMed

    Aizawa, S; Miyasawa-Hori, H; Nakajo, K; Washio, J; Mayanagi, H; Fukumoto, S; Takahashi, N

    2009-01-01

    This study evaluated acid production from cooked starch by Streptococcus mutans, Streptococcus sobrinus, Streptococcus sanguinis and Streptococcus mitis, and the effects of alpha-amylase inhibitors (maltotriitol and acarbose) and xylitol on acid production. Streptococcal cell suspensions were anaerobically incubated with various carbohydrates that included cooked potato starch in the presence or absence of alpha-amylase. Subsequently, the fall in pH and the acid production rate at pH 7.0 were measured. In addition, the effects of adding alpha-amylase inhibitors and xylitol to the reaction mixture were evaluated. In the absence of alpha-amylase, both the fall in pH and the acid production rate from cooked starch were small. On the other hand, in the presence of alpha-amylase, the pH fell to 3.9-4.4 and the acid production rate was 0.61-0.92 micromol per optical density unit per min. These values were comparable to those for maltose. When using cooked starch, the fall in pH by S. sanguinis and S. mitis was similar to that by S. mutans and S. sobrinus. For all streptococci, alpha-amylase inhibitors caused a decrease in acid production from cooked starch, although xylitol only decreased acid production by S. mutans and S. sobrinus. These results suggest that cooked starch is potentially acidogenic in the presence of alpha-amylase, which occurs in the oral cavity. In terms of the acidogenic potential of cooked starch, S. sanguinis and S. mitis were comparable to S. mutans and S. sobrinus. Alpha-amylase inhibitors and xylitol might moderate this activity. PMID:19136828

  7. The drug 5-aminosalicylic acid rescues alpha 1-proteinase inhibitor from the neutrophil oxidative inactivation. A possible contribution to its therapeutic action in ulcerative colitis.

    PubMed

    Ottonello, L; Dapino, P; Pastorino, G; Vitale, E; Dallegri, F

    1992-01-01

    The glycoprotein alpha 1-proteinase inhibitor is the specific inhibitor of neutrophil elastase, a major tissue-damaging protease. When incubated with activated neutrophils, alpha 1-proteinase inhibitor lost its pancreatic porcine elastase inhibitory capacity and became incapable of forming a sodium dodecyl sulphate-stable complex with pancreatic porcine elastase. Inhibitors and scavengers of neutrophil-derived reactive oxygen species outlined the crucial role of hypochlorous acid in the alpha 1-proteinase inhibitor inactivation. Moreover, the drug 5-aminosalicylic acid prevented the inactivation of alpha 1-proteinase inhibitor by neutrophils in a dose-dependent manner. Finally, when the capacity of 5-aminosalicylic acid to rescue alpha 1-proteinase inhibitor from the neutrophil-derived attack was plotted as a function of the 5-aminosalicylic acid ability to scavenge neutrophil-derived hypochlorous acid, a positive linear relationship was found. Thus, our results provide a direct evidence that 5-aminosalicylic acid is able to prevent the oxidative inactivation of alpha 1-proteinase inhibitor by neutrophils. Therefore, we suggest that the drug has the potential to limit the elastase-mediated damage of colonic connective tissue by creating a microenvironment of active alpha 1-proteinase inhibitor around the neutrophils. PMID:1521714

  8. Dimerization of Bacterial Diaminopimelate Decarboxylase Is Essential for Catalysis.

    PubMed

    Peverelli, Martin G; Soares da Costa, Tatiana P; Kirby, Nigel; Perugini, Matthew A

    2016-04-29

    Diaminopimelate decarboxylase (DAPDC) catalyzes the final step in the diaminopimelate biosynthesis pathway of bacteria. The product of the reaction is the essential amino acid l-lysine, which is an important precursor for the synthesis of the peptidoglycan cell wall, housekeeping proteins, and virulence factors of bacteria. Accordingly, the enzyme is a promising antibacterial target. Previous structural studies demonstrate that DAPDC exists as monomers, dimers, and tetramers in the crystal state. However, the active oligomeric form has not yet been determined. We show using analytical ultracentrifugation, small angle x-ray scattering, and enzyme kinetic analyses in solution that the active form of DAPDC from Bacillus anthracis, Escherichia coli, Mycobacterium tuberculosis, and Vibrio cholerae is a dimer. The importance of dimerization was probed further by generating dimerization interface mutants (N381A and R385A) of V. cholerae DAPDC. Our studies indicate that N381A and R385A are significantly attenuated in catalytic activity, thus confirming that dimerization of DAPDC is essential for function. These findings provide scope for the development of new antibacterial agents that prevent DAPDC dimerization. PMID:26921318

  9. Substrate properties of C1 inhibitor Ma (alanine 434----glutamic acid). Genetic and structural evidence suggesting that the P12-region contains critical determinants of serine protease inhibitor/substrate status.

    PubMed

    Skriver, K; Wikoff, W R; Patston, P A; Tausk, F; Schapira, M; Kaplan, A P; Bock, S C

    1991-05-15

    The serine protease inhibitor (serpin) C1 inhibitor inactivates enzymes involved in the regulation of vascular permeability. A patient from the Ma family with the genetic disorder hereditary angioedema inherited a dysfunctional C1 inhibitor allele. Relative to normal plasma, the patients's plasma contained an additional C1 inhibitor immunoreactive band, which comigrated with normal C1 inhibitor cleaved by plasma kallikrein, C1s, or factor XIIa. C1 inhibitor Ma did not react with a monoclonal antibody to a neoepitope that is present in complexed and cleaved normal C1 inhibitor, suggesting conformational differences between cleaved normal C1- inhibitor and cleaved C1 inhibitor Ma. Molecular cloning and sequencing of exon 8 of the C1 inhibitor Ma allele revealed a single C to A mutation, changing alanine 434 to glutamic acid. Ala 434 of C1 inhibitor aligns with the P12 residue of the prototypical serpin alpha 1-antitrypsin. The P12 amino acid of all inhibitory serpins is alanine, and it is present in a highly conserved region on the amino-terminal side of the serpin-reactive center loop. Whereas normal C1 inhibitor expressed by transfected COS-1 cells formed complexes with and was cleaved by kallikrein, fXIIa, and C1s, COS-1-expressed Ala434---Glu C1 inhibitor was cleaved by these enzymes but did not form complexes with them. These results, together with evidence from other studies, suggest that serpin protease inhibitor activity is the result of protein conformational change that occurs when the P12 region of a serpin moves from a surface location, on the reactive site loop of the native molecule, to an internal location within sheet A of the complexed inhibitor. PMID:2026621

  10. The complete amino acid sequence of the major Kunitz trypsin inhibitor from the seeds of Prosopsis juliflora.

    PubMed

    Negreiros, A N; Carvalho, M M; Xavier Filho, J; Blanco-Labra, A; Shewry, P R; Richardson, M

    1991-01-01

    The major inhibitor of trypsin in seeds of Prosopsis juliflora was purified by precipitation with ammonium sulphate, ion-exchange column chromatography on DEAE- and CM-Sepharose and preparative reverse phase HPLC on a Vydac C-18 column. The protein inhibited trypsin in the stoichiometric ratio of 1:1, but had only weak activity against chymotrypsin and did not inhibit human salivary or porcine pancreatic alpha-amylases. SDS-PAGE indicated that the inhibitor has a Mr of ca 20,000, and IEF-PAGE showed that the pI is 8.8. The complete amino acid sequence was determined by automatic degradation, and by DABITC/PITC microsequence analysis of peptides obtained from enzyme digestions of the reduced and S-carboxymethylated protein with trypsin, chymotrypsin, elastase, the Glu-specific protease from S. aureus and the Lys-specific protease from Lysobacter enzymogenes. The inhibitor consisted of two polypeptide chains, of 137 residues (alpha chain) and 38 residues (beta chain) linked together by a single disulphide bond. The amino acid sequence of the protein exhibited homology with a number of Kunitz proteinase inhibitors from other legume seeds, the bifunctional subtilisin/alpha-amylase inhibitors from cereals and the taste-modifying protein miraculin. PMID:1367792

  11. Synthesis, docking, and biological studies of phenanthrene β-diketo acids as novel HIV-1 integrase inhibitors

    PubMed Central

    Sharma, Horrick; Sanchez, Tino W.; Neamati, Nouri; Detorio, Mervi; Schinazi, Raymond F.; Cheng, Xiaolin; Buolamwini, John K.

    2013-01-01

    In the present study we report the synthesis of halogen-substituted phenanthrene β-diketo acids as new HIV-1 integrase inhibitors. The target phenanthrenes were obtained using both standard thermal- and microwave-assisted synthesis. 4-(6-Chlorophenanthren-2-yl)-2,4-dioxobutanoic acid (18) was the most active compound of the series that inhibited both 3′-end processing (3′-P) and strand transfer (ST) with IC50 values of 5 and 1.3 μM, respectively. Docking studies revealed two predominant binding modes that were distinct from the binding modes of raltegravir and elvitegravir, and suggest a novel binding region in the IN active site. Moreover, these compounds do not interact significantly with some of the key amino acids (Q148 and N155) implicated in viral resistance. Therefore, this series of compounds can further be investigated for a possible chemotype to circumvent resistance to clinical HIV-1 IN inhibitors. PMID:24091080

  12. Retinoids increase transglutaminase activity and inhibit ornithine decarboxylase activity in Chinese hamster ovary cells and in melanoma cells stimulated to differentiate.

    PubMed Central

    Scott, K F; Meyskens, F L; Russell, D H

    1982-01-01

    Transglutaminase (TGase; R-glutaminyl-peptide:amine gamma-glutamyltransferase, EC 2.3.2.13) and ornithine decarboxylase (ODCase; L-ornithine carboxy-lyase, EC 4.1.1.17) activities were measured after the addition of retinoid analogs to Chinese hamster ovary (CHO) cells released from quiescence and Cloudman S91 (CCL 53.1) mouse melanoma cells stimulated to differentiate with alpha-melanocyte-stimulating hormone (MSH, melanotropin). In both cell culture lines, we detected a biphasic increase in TGase activity and a single peak of ODCase activity within 7 hr after release or stimulation. Retinoid analogs altered the expression of the initial TGase peak in both CHO and melanoma cells. Retinol increased the activity of TGase 1 hr after release in CHO cells, and the activity remained elevated until hr 4. A broad peak of TGase activity also occurred after the addition of alpha-difluoromethylornithine, an irreversible inhibitor of ODCase, and after addition of alpha-difluoromethylornithine plus retinol. In mouse melanoma cells, retinoic acid plus MSH markedly enhanced the activity of the initial TGase peak compared to MSH alone. Retinoic acid alone also increased TGase activity biphasically in these cells without the addition of MSH. These studies suggest that retinoid effects that increase TGase activity may alter the ODCase expression in proliferation and differentiation. PMID:6125941

  13. Novel 2-oxoimidazolidine-4-carboxylic acid derivatives as Hepatitis C virus NS3-4A serine protease inhibitors: synthesis, activity, and X-ray crystal structure of an enzyme inhibitor complex

    SciTech Connect

    Arasappan, Ashok; Njoroge, F. George; Parekh, Tejal N.; Yang, Xiaozheng; Pichardo, John; Butkiewicz, Nancy; Prongay, Andrew; Yao, Nanhua; Girijavallabhan, Viyyoor

    2008-06-30

    Synthesis and HCV NS3 serine protease inhibitory activity of some novel 2-oxoimidazolidine-4-carboxylic acid derivatives are reported. Inhibitors derived from this new P2 core exhibited activity in the low {micro}M range. X-ray structure of an inhibitor, 15c bound to the protease is presented.

  14. Fatty acid transport protein-2 inhibitor Grassofermata/CB5 protects cells against lipid accumulation and toxicity

    SciTech Connect

    Saini, Nipun; Black, Paul N.; Montefusco, David; DiRusso, Concetta C.

    2015-09-25

    The inhibition of the fatty acid uptake into non-adipose tissues provides an attractive target for prevention of lipotoxicity leading to obesity-associated non-alcoholic fatty liver disease and type 2 diabetes. Fatty acid transport proteins (FATPs) are bifunctional proteins involved in the uptake and activation of fatty acids by esterification with coenzyme A. Here we characterize Grassofermata/CB5, previously identified as a fatty acid uptake inhibitor directed against HsFATP2. The compound was effective in inhibiting the uptake of fatty acids in the low micro-molar range (IC{sub 50} 8–11 μM) and prevented palmitate-mediated lipid accumulation and cell death in cell lines that are models for intestines, liver, muscle and pancreas. In adipocytes, uptake inhibition was less effective (IC{sub 50} 58 μM). Inhibition was specific for long chain fatty acids and was ineffective toward medium chain fatty acids, which are transported by diffusion. Kinetic analysis of Grassofermata-dependent FA transport inhibition verified a non-competitive mechanism. By comparison with Grassofermata, several atypical antipsychotic drugs previously implicated as inhibitors of FA uptake were ineffectual. In mice Grassofermata decreased absorption of {sup 13}C-oleate demonstrating its potential as a therapeutic agent. - Highlights: • Grassofermata is a small compound inhibitor of FATP2. • Uptake inhibition is specific for long chain fatty acids. • Uptake kinetics shows low specificity for adipocytes compared to other cell types. • Inhibition is by a non-competitive mechanism. • Atypical antipsychotics do not inhibit FA uptake by comparison with Grassofermata.

  15. Aurintricarboxylic Acid Is a Potent Inhibitor of Influenza A and B Virus Neuraminidases

    PubMed Central

    Farnsworth, Aaron; Brown, Earl G.; Van Domselaar, Gary; He, Runtao; Li, Xuguang

    2009-01-01

    Background Influenza viruses cause serious infections that can be prevented or treated using vaccines or antiviral agents, respectively. While vaccines are effective, they have a number of limitations, and influenza strains resistant to currently available anti-influenza drugs are increasingly isolated. This necessitates the exploration of novel anti-influenza therapies. Methodology/Principal Findings We investigated the potential of aurintricarboxylic acid (ATA), a potent inhibitor of nucleic acid processing enzymes, to protect Madin-Darby canine kidney cells from influenza infection. We found, by neutral red assay, that ATA was protective, and by RT-PCR and ELISA, respectively, confirmed that ATA reduced viral replication and release. Furthermore, while pre-treating cells with ATA failed to inhibit viral replication, pre-incubation of virus with ATA effectively reduced viral titers, suggesting that ATA may elicit its inhibitory effects by directly interacting with the virus. Electron microscopy revealed that ATA induced viral aggregation at the cell surface, prompting us to determine if ATA could inhibit neuraminidase. ATA was found to compromise the activities of virus-derived and recombinant neuraminidase. Moreover, an oseltamivir-resistant H1N1 strain with H274Y was also found to be sensitive to ATA. Finally, we observed additive protective value when infected cells were simultaneously treated with ATA and amantadine hydrochloride, an anti-influenza drug that inhibits M2-ion channels of influenza A virus. Conclusions/Significance Collectively, these data suggest that ATA is a potent anti-influenza agent by directly inhibiting the neuraminidase and could be a more effective antiviral compound when used in combination with amantadine hydrochloride. PMID:20020057

  16. Boronic acid-containing proteasome inhibitors: alert to potential pharmaceutical bioactivation.

    PubMed

    Li, Austin C; Yu, Erya; Ring, Steven C; Chovan, James P

    2013-04-15

    Medicinal chemists try to avoid certain organic functional groups, summarized in an ever-growing list, in order to avoid the potential bioactivation to reactive metabolites. To add to that alert list, we report herein that boronic acid-containing compound structures, such as those found in proteasome inhibitors bortezomib and ixazomib, can become bioactivated to chemically reactive imine amide metabolites. Test compounds, ixazomib and bortezomib, were incubated in vitro using human liver fractions containing cytosol and microsomes (S9) under conventional conditions in the presence of GSH. Metabolites were then analyzed using LC-MS(n) with or without online hydrogen-deuterium exchange (HDX) liquid chromatography coupled with an LTQ-Orbitrap. The exact mass measurements of both the precursor and product ions were acquired through data dependent acquisition and compared with theoretical values of proposed fragment ions. Upon deboronation catalyzed by cytochrome P450 enzymes, both test compounds formed imine amide metabolites that were identified by high resolution exact mass measurements in both normal aqueous and HDX HPLC-MS analysis. GSH conjugates were also identified and were postulated as nucleophilic addition of GSH to the imine amide metabolites. All mass spectrometric and HDX measurements of these GSH conjugates proved that the GSH unit was added to the carbon atom of the imine amide partial structure, hence demonstrating the electrophilic property of these imine amide metabolites. The awareness of the formation of electrophilic imine amide metabolites from boronic acid-containing compounds, where the boron atom is bonded to a carbon atom adjacent to an amide nitrogen, should help in drug candidate design and optimization with regard to avoiding potential bioactivation. PMID:23514361

  17. Examination of the Addictive and Behavioral Properties of Fatty Acid-Binding Protein Inhibitor SBFI26.

    PubMed

    Thanos, Panayotis K; Clavin, Brendan H; Hamilton, John; O'Rourke, Joseph R; Maher, Thomas; Koumas, Christopher; Miao, Erick; Lankop, Jessenia; Elhage, Aya; Haj-Dahmane, Samir; Deutsch, Dale; Kaczocha, Martin

    2016-01-01

    The therapeutic properties of cannabinoids have been well demonstrated but are overshadowed by such adverse effects as cognitive and motor dysfunction, as well as their potential for addiction. Recent research on the natural lipid ligands of cannabinoid receptors, also known as endocannabinoids, has shed light on the mechanisms of intracellular transport of the endocannabinoid anandamide by fatty acid-binding proteins (FABPs) and subsequent catabolism by fatty acid amide hydrolase. These findings facilitated the recent development of SBFI26, a pharmacological inhibitor of epidermal- and brain-specific FABP5 and FABP7, which effectively increases anandamide signaling. The goal of this study was to examine this compound for any possible rewarding and addictive properties as well as effects on locomotor activity, working/recognition memory, and propensity for sociability and preference for social novelty (SN) given its recently reported anti-inflammatory and analgesic properties. Male C57BL mice were split into four treatment groups and conditioned with 5.0, 20.0, 40.0 mg/kg SBFI26, or vehicle during a conditioned place preference (CPP) paradigm. Following CPP, mice underwent a battery of behavioral tests [open field, novel object recognition (NOR), social interaction (SI), and SN] paired with acute SBFI26 administration. Results showed that SBFI26 did not produce CPP or conditioned place aversion regardless of dose and did not induce any differences in locomotor and exploratory activity during CPP- or SBFI26-paired open field activity. We also observed no differences between treatment groups in NOR, SI, and SN. In conclusion, as SBFI26 was shown previously by our group to have significant analgesic and anti-inflammatory properties, here we show that it does not pose a risk of dependence or motor and cognitive impairment under the conditions tested. PMID:27092087

  18. Examination of the Addictive and Behavioral Properties of Fatty Acid-Binding Protein Inhibitor SBFI26

    PubMed Central

    Thanos, Panayotis K.; Clavin, Brendan H.; Hamilton, John; O’Rourke, Joseph R.; Maher, Thomas; Koumas, Christopher; Miao, Erick; Lankop, Jessenia; Elhage, Aya; Haj-Dahmane, Samir; Deutsch, Dale; Kaczocha, Martin

    2016-01-01

    The therapeutic properties of cannabinoids have been well demonstrated but are overshadowed by such adverse effects as cognitive and motor dysfunction, as well as their potential for addiction. Recent research on the natural lipid ligands of cannabinoid receptors, also known as endocannabinoids, has shed light on the mechanisms of intracellular transport of the endocannabinoid anandamide by fatty acid-binding proteins (FABPs) and subsequent catabolism by fatty acid amide hydrolase. These findings facilitated the recent development of SBFI26, a pharmacological inhibitor of epidermal- and brain-specific FABP5 and FABP7, which effectively increases anandamide signaling. The goal of this study was to examine this compound for any possible rewarding and addictive properties as well as effects on locomotor activity, working/recognition memory, and propensity for sociability and preference for social novelty (SN) given its recently reported anti-inflammatory and analgesic properties. Male C57BL mice were split into four treatment groups and conditioned with 5.0, 20.0, 40.0 mg/kg SBFI26, or vehicle during a conditioned place preference (CPP) paradigm. Following CPP, mice underwent a battery of behavioral tests [open field, novel object recognition (NOR), social interaction (SI), and SN] paired with acute SBFI26 administration. Results showed that SBFI26 did not produce CPP or conditioned place aversion regardless of dose and did not induce any differences in locomotor and exploratory activity during CPP- or SBFI26-paired open field activity. We also observed no differences between treatment groups in NOR, SI, and SN. In conclusion, as SBFI26 was shown previously by our group to have significant analgesic and anti-inflammatory properties, here we show that it does not pose a risk of dependence or motor and cognitive impairment under the conditions tested. PMID:27092087

  19. A lysophosphatidic acid analogue is revealed as a potent inhibitor of phosphatidylcholine synthesis, inducing apoptosis.

    PubMed Central

    Gueguen, Geneviéve; Granci, Virginie; Rogalle, Pierre; Briand-Mésange, Fabienne; Wilson, Michéle; Klaébé, Alain; Tercé, François; Chap, Hugues; Salles, Jean-Pierre; Simon, Marie-Françoise; Gaits, Frédérique

    2002-01-01

    A previous study demonstrated that cross-desensitization experiments performed with the lysophosphatidic acid (LPA) analogues (R)- and (S)-N-palmitoyl-norleucinol 1-phosphate (PNPAs) inhibited LPA-induced platelet aggregation without any stereospecificity. Here we report opposite biological effects of the two enantiomers on mitogenesis of IMR-90 fibroblasts in relation to their respective metabolism. (R)PNPA was proliferative, while (S)PNPA induced apoptosis by specifically inhibiting phosphatidylcholine biosynthesis at the last step of the CDP-choline pathway controlled by cholinephosphotransferase. This effect was not direct but required dephosphorylation of PNPAs by ecto-lipid phosphate phosphatase before cellular uptake of the generated N-palmitoyl-norleucinols (PNOHs). Inhibition of cholinephosphotransferase by the derivative (S)PNOH was confirmed by an in vitro assay. (S)PNPA proapoptotic effects led us to clarify the mechanism linking cholinephosphotransferase inhibition to apoptosis. Three proapoptotic responses were observed: the activation of caspase-3, the production of ceramides from newly synthesized pools (as demonstrated by the inhibitor Fumonisin B1) and finally the activation of stress-activated protein kinase, p38 and c-Jun N-terminal kinases 1/2, as a result of ceramide increase. Thus our data demonstrate that synthetic analogues of LPA might display stereospecific effects leading to apoptosis independently of classical LPA-activated pathways. PMID:12197836

  20. Evaluation of the radiolabeled boronic acid-based FAP inhibitor MIP-1232 for atherosclerotic plaque imaging.

    PubMed

    Meletta, Romana; Müller Herde, Adrienne; Chiotellis, Aristeidis; Isa, Malsor; Rancic, Zoran; Borel, Nicole; Ametamey, Simon M; Krämer, Stefanie D; Schibli, Roger

    2015-01-01

    Research towards the non-invasive imaging of atherosclerotic plaques is of high clinical priority as early recognition of vulnerable plaques may reduce the incidence of cardiovascular events. The fibroblast activation protein alpha (FAP) was recently proposed as inflammation-induced protease involved in the process of plaque vulnerability. In this study, FAP mRNA and protein levels were investigated by quantitative polymerase chain reaction and immunohistochemistry, respectively, in human endarterectomized carotid plaques. A published boronic-acid based FAP inhibitor, MIP-1232, was synthetized and radiolabeled with iodine-125. The potential of this radiotracer to image plaques was evaluated by in vitro autoradiography with human carotid plaques. Specificity was assessed with a xenograft with high and one with low FAP level, grown in mice. Target expression analyses revealed a moderately higher protein level in atherosclerotic plaques than normal arteries correlating with plaque vulnerability. No difference in expression was determined on mRNA level. The radiotracer was successfully produced and accumulated strongly in the FAP-positive SK-Mel-187 melanoma xenograft in vitro while accumulation was negligible in an NCI-H69 xenograft with low FAP levels. Binding of the tracer to endarterectomized tissue was similar in plaques and normal arteries, hampering its use for atherosclerosis imaging. PMID:25633335

  1. Suberoylanilide hydroxamic acid, a histone deacetylase inhibitor, attenuates postoperative cognitive dysfunction in aging mice

    PubMed Central

    Jia, Min; Liu, Wen-Xue; Sun, He-Liang; Chang, Yan-Qing; Yang, Jiao-Jiao; Ji, Mu-Huo; Yang, Jian-Jun; Feng, Chen-Zhuo

    2015-01-01

    Postoperative cognitive dysfunction (POCD) is a recognized clinical entity characterized with cognitive deficits after anesthesia and surgery, especially in aged patients. Previous studies have shown that histone acetylation plays a key role in hippocampal synaptic plasticity and memory formation. However, its role in POCD remains to be determined. Here, we show that suberoylanilide hydroxamic acid (SAHA), a histone deacetylase inhibitor, attenuates POCD in aging Mice. After exposed to the laparotomy, a surgical procedure involving an incision into abdominal walls to examine the abdominal organs, 16- but not 3-month old male C57BL/6 mice developed obvious cognitive impairments in the test of long-term contextual fear conditioning. Intracerebroventricular (i.c.v.) injection of SAHA at the dose of (20 μg/2 μl) 3 h before and daily after the laparotomy restored the laparotomy-induced reduction of hippocampal acetyl-H3 and acetyl-H4 levels and significantly attenuated the hippocampus-dependent long-term memory (LTM) impairments in 16-month old mice. SAHA also reduced the expression of cleaved caspase-3, inducible nitric oxide synthase (iNOS) and N-methyl-D-aspartate (NMDA) receptor-calcium/calmodulin dependent kinase II (CaMKII) pathway, and increased the expression of brain-derived neurotrophic factor (BDNF), synapsin 1, and postsynaptic density 95 (PSD95). Taken together, our data suggest that the decrease of histone acetylation contributes to POCD and may serve as a target to improve the neurological outcome of POCD. PMID:26441515

  2. The Histone Deacetylase Inhibitor Suberoylanilide Hydroxamic Acid (SAHA) Confers Acute Neuroprotection After Intracerebral Hemorrhage in Mice.

    PubMed

    Sukumari-Ramesh, Sangeetha; Alleyne, Cargill H; Dhandapani, Krishnan M

    2016-04-01

    Spontaneous intracerebral hemorrhage (ICH) is a stroke subtype with no effective treatment. Though ICH is known to induce severe neurological damage, the molecular mechanisms of neurological injury after ICH remain largely unclear. Given the emerging role of epigenetic mechanisms in neurodegeneration, the present study evaluated whether suberoylanilide hydroxamic acid (SAHA: vorinostat), a clinically well-tolerated pan-histone deacetylase inhibitor (HDACi), would attenuate neurological injury and improve functional outcomes in a preclinical model of ICH. Mice were administered with SAHA or vehicle after an induction of ICH and acute neuronal death, glial activation, and neurological outcomes were assessed. SAHA-treated mice exhibited less neurodegeneration with concomitant improvement in neurological outcomes than vehicle-treated mice. Furthermore, SAHA downregulated glial activation and the expression of heme oxygenase-1, a stress-inducible enzyme that plays critical roles in neurological damage after ICH. Altogether, the data strongly suggest the role of epigenetic mechanisms in inducing neurological injury after ICH and raise the possible clinical utility of SAHA for therapeutic intervention after ICH. PMID:26338677

  3. Synthesis of novel beta-lactone inhibitors of fatty acid synthase.

    PubMed

    Richardson, Robyn D; Ma, Gil; Oyola, Yatsandra; Zancanella, Manuel; Knowles, Lynn M; Cieplak, Piotr; Romo, Daniel; Smith, Jeffrey W

    2008-09-11

    Fatty acid synthase (FAS) is necessary for growth and survival of tumor cells and is a promising drug target for oncology. Here, we report on the syntheses and activity of novel inhibitors of the thioesterase domain of FAS. Using the structure of orlistat as a starting point, which contains a beta-lactone as the central pharmacophore, 28 novel congeners were synthesized and examined. Structural features such as the length of the alpha- and beta-alkyl chains, their chemical composition, and amino ester substitutions were altered and the resulting compounds explored for inhibitory activity toward the thioesterase domain of FAS. Nineteen congeners show improved potency for FAS in biochemical assays relative to orlistat. Three of that subset, including the natural product valilactone, also display an increased potency in inducing tumor cell death and improved solubility compared to orlistat. These findings support the idea that an orlistat congener can be optimized for use in a preclinical drug design and for clinical drug development. PMID:18710210

  4. Synthesis of Novel β-Lactone Inhibitors of Fatty Acid Synthase

    PubMed Central

    Richardson, Robyn D.; Ma, Gil; Oyola, Yatsandra; Zancanella, Manuel; Knowles, Lynn M.; Cieplak, Piotr; Romo, Daniel; Smith, Jeffrey W.

    2011-01-01

    Fatty acid synthase (FAS) is necessary for growth and survival of tumor cells and is a promising drug target for oncology. Here, we report on the syntheses and activity of novel inhibitors of the thioesterase domain of FAS. Using the structure of orlistat as a starting point, which contains a β-lactone as the central pharmacophore, 28 novel congeners were synthesized and examined. Structural features such as the length of the α- and β-alkyl chains, their chemical composition, and amino ester substitutions were altered and the resulting compounds explored for inhibitory activity toward the thioesterase domain of FAS. Nineteen congeners show improved potency for FAS in biochemical assays relative to orlistat. Three of that subset, including the natural product valilactone, also display an increased potency in inducing tumor cell death and improved solubility compared to orlistat. These findings support the idea that an orlistat congener can be optimized for use in a preclinical drug design and for clinical drug development. PMID:18710210

  5. Mechanism for release of arachidonic acid during guinea pig platelet aggregation: a role for the diacylglycerol lipase inhibitor RHC 80267

    SciTech Connect

    Amin, D.

    1986-01-01

    The mechanism of the release of arachidonic acid from phospholipids after the stimulation of guinea pig platelets with collagen, thrombin and platelet activating factor (PAF) was studied. RHC 80267, a diacylglycerol lipase inhibitor, and indomethacin, a cyclooxygenase inhibitor, were used. Various in vitro assays for enzymes involved in arachidonic acid release and metabolism were conducted. Platelet aggregation and simultaneous release of ADP from platelets were monitored using a Chrono-log Lumiaggregometer. Platelets were labeled with (/sup 14/C)arachidonic acid to facilitate sensitive determination of small changes in platelet phospholipids during platelet aggregation. In the present investigation it is shown that collagen, thrombin and PAF increased phospholipase C activity. It was also discovered that cyclooxygenase products were responsible for further stimulation (a positive feed-back) of phospholipase C activity, while diacylglycerol provided a negative feed-back control over receptor-stimulated phospholipase C activity and inhibited ADP release. The guinea pig platelet is an ideal model to study phospholipase C-diacylglycerol lipase pathway for the release of arachidonic acid from platelet phospholipids because it does not have any phospholipase A/sub 2/ activity. It was observed that cyclooxygenase products were responsible for collagen-induced guinea pig platelet aggregation. Indomethacin completely inhibited collagen-induced platelet aggregation, was less effective against thrombin, and had no effect on PAF-induced platelet aggregation. On the other hand, RHC 80267 was a powerful inhibitor of aggregation and ADP release induced by all three of these potent aggregating agents.

  6. Identification of essential amino acid residues of an alpha-amylase inhibitor from Phaseolus vulgaris white kidney beans.

    PubMed

    Takahashi, T; Hiramoto, S; Wato, S; Nishimoto, T; Wada, Y; Nagai, K; Yamaguchi, H

    1999-11-01

    Kidney bean (Phaseolus vulgaris) alpha-amylase inhibitors, which are bivalent inhibitors with the subunit stoichiometry of (alphabeta)(2) complex, have been inferred to contain unique arginine, tryptophan, and tyrosine residues essential for the inhibitory activity. To test the validity of this inference, an attempt was made to identify the essential amino acid residues of a white kidney bean (P. vulgaris) alpha-amylase inhibitor (PHA-I) by using the chemical modification technique combined with amino acid sequencing and mass spectrometry. Exhaustive modification of the arginine residues by phenylglyoxal did not lead to a marked loss of activity, suggesting that no arginine residue is directly associated with the inhibitory activity. N-Bromosuccinimide treatment of PHA-I in the presence or absence of a substrate alpha-amylase revealed the involvement of two tryptophan residues in alpha-amylase inhibition, and they were identified as Trp188 of the beta-subunit by amino acid sequencing and mass spectrometry of lysylendopeptidase peptides. Further, two tyrosine residues were preferentially modified either by N-acetylimidazole or by tetranitromethane, resulting in a concomitant loss of most of the PHA-I activity. Amino acid sequencing of the lysylendopeptidase peptides from a tetranitromethane-modified PHA-I identified Tyr186 of the beta-subunit as an essential residue. PMID:10544275

  7. Novel human D-amino acid oxidase inhibitors stabilize an active-site lid-open conformation

    PubMed Central

    Terry-Lorenzo, Ryan T.; Chun, Lawrence E.; Brown, Scott P.; Heffernan, Michele L. R.; Fang, Q. Kevin; Orsini, Michael A.; Pollegioni, Loredano; Hardy, Larry W.; Spear, Kerry L.; Large, Thomas H.

    2014-01-01

    The NMDAR (N-methyl-D-aspartate receptor) is a central regulator of synaptic plasticity and learning and memory. hDAAO (human D-amino acid oxidase) indirectly reduces NMDAR activity by degrading the NMDAR co-agonist D-serine. Since NMDAR hypofunction is thought to be a foundational defect in schizophrenia, hDAAO inhibitors have potential as treatments for schizophrenia and other nervous system disorders. Here, we sought to identify novel chemicals that inhibit hDAAO activity. We used computational tools to design a focused, purchasable library of compounds. After screening this library for hDAAO inhibition, we identified the structurally novel compound, ‘compound 2’ [3-(7-hydroxy-2-oxo-4-phenyl-2H-chromen-6-yl)propanoic acid], which displayed low nM hDAAO inhibitory potency (Ki=7 nM). Although the library was expected to enrich for compounds that were competitive for both D-serine and FAD, compound 2 actually was FAD uncompetitive, much like canonical hDAAO inhibitors such as benzoic acid. Compound 2 and an analog were independently co-crystalized with hDAAO. These compounds stabilized a novel conformation of hDAAO in which the active-site lid was in an open position. These results confirm previous hypotheses regarding active-site lid flexibility of mammalian D-amino acid oxidases and could assist in the design of the next generation of hDAAO inhibitors. PMID:25001371

  8. Biological activities of novel zaragozic acids, the potent inhibitors of squalene synthase, produced by the fungus, Mollisia sp. SANK 10294.

    PubMed

    Tanimoto, T; Hamano, K; Onodera, K; Hosoya, T; Kakusaka, M; Hirayama, T; Shimada, Y; Koga, T; Tsujita, Y

    1997-05-01

    Four novel zaragozic acids, F-10863A, B, C and D, were isolated from a culture broth of the fungus Mollisia sp. SANK 10294. F-10863 compounds contain a 4,6,7-trihydroxy-2,8-dioxyobicyclo-[3.2.1]octane-3,4,5-tricarboxyl ic acid core like previously reported zaragozic acids, but the structures of the side chains are different. Recently, it was found that F-10863A is identical to zaragozic acid D3, while the other three are novel compounds. F-10863 compounds are potent inhibitors of squalene synthase like previously reported zaragozic acids, and, furthermore, they exhibit serum cholesterol-lowering activity in vivo. PMID:9207908

  9. Design and synthesis of inhibitors incorporating beta -amino acids of metalloendopeptidase EC 3.4.24.15.

    PubMed

    Steer, D L; Lew, R A; Perlmutter, P; Smith, A I; Aguilar, M I

    2000-09-01

    Endopeptidase EC 3.4.24.15 (EP 24.15) is a thermolysin-like metalloendopeptidase which is expressed widely throughout the body, with the highest concentrations in the brain, pituitary and testis. While the precise role of EP 24.15 remains unknown, it is thought to participate in the regulated metabolism of a number of specific neuropeptides. Of the limited number of inhibitors described for EP 24.15, N-[1-(R,S)-carboxy-3-phenylpropyl]-Ala-Ala-Tyr-p-amino benzoate (CFP) is the most widely studied. CFP is a potent and specific inhibitor, but is unstable in vivo due to its cleavage between the alanine and tyrosine residues by the enzyme neprilysin (EP 24.11). The cpp-Ala-Ala N-terminal product of this cleavage is a potent inhibitor of angiotensin converting enzyme, which further limits the use of CFP in vivo. To generate specific inhibitors of EP 24.15 that are resistant to in vivo proteolysis by EP 24.11, beta-amino acids have been incorporated into the structure of CFP. We have prepared racemic mixtures of beta-amino acids containing proteogenic side chains, which are 9-fluorenylmethoxycarbonyl (Fmoc)-protected, and several analogues of CFP containing beta-amino acids have been synthesized by solid phase peptide synthesis. The results of stability and inhibitory studies of these new analogues show that the incorporation of beta-amino acids adjacent to the scissile bond can indeed stabilize the peptides against cleavage by EP 24.11 and still inhibit EP 24.15. The results obtained in these studies demonstrate the potential of these amino acids in the synthesis of peptidomimetics and in the design of new stable and specific therapeutics. PMID:11016884

  10. Effects of down-regulating ornithine decarboxylase upon putrescine-associated metabolism and growth in Nicotiana tabacum L.

    PubMed Central

    Dalton, Heidi L.; Blomstedt, Cecilia K.; Neale, Alan D.; Gleadow, Ros; DeBoer, Kathleen D.; Hamill, John D.

    2016-01-01

    Transgenic plants of Nicotiana tabacum L. homozygous for an RNAi construct designed to silence ornithine decarboxylase (ODC) had significantly lower concentrations of nicotine and nornicotine, but significantly higher concentrations of anatabine, compared with vector-only controls. Silencing of ODC also led to significantly reduced concentrations of polyamines (putrescine, spermidine and spermine), tyramine and phenolamides (caffeoylputrescine and dicaffeoylspermidine) with concomitant increases in concentrations of amino acids ornithine, arginine, aspartate, glutamate and glutamine. Root transcript levels of S-adenosyl methionine decarboxylase, S-adenosyl methionine synthase and spermidine synthase (polyamine synthesis enzymes) were reduced compared with vector controls, whilst transcript levels of arginine decarboxylase (putrescine synthesis), putrescine methyltransferase (nicotine production) and multi-drug and toxic compound extrusion (alkaloid transport) proteins were elevated. In contrast, expression of two other key proteins required for alkaloid synthesis, quinolinic acid phosphoribosyltransferase (nicotinic acid production) and a PIP-family oxidoreductase (nicotinic acid condensation reactions), were diminished in roots of odc-RNAi plants relative to vector-only controls. Transcriptional and biochemical differences associated with polyamine and alkaloid metabolism were exacerbated in odc-RNAi plants in response to different forms of shoot damage. In general, apex removal had a greater effect than leaf wounding alone, with a combination of these injury treatments producing synergistic responses in some cases. Reduced expression of ODC appeared to have negative effects upon plant growth and vigour with some leaves of odc-RNAi lines being brittle and bleached compared with vector-only controls. Together, results of this study demonstrate that ornithine decarboxylase has important roles in facilitating both primary and secondary metabolism in Nicotiana. PMID

  11. Effects of down-regulating ornithine decarboxylase upon putrescine-associated metabolism and growth in Nicotiana tabacum L.

    PubMed

    Dalton, Heidi L; Blomstedt, Cecilia K; Neale, Alan D; Gleadow, Ros; DeBoer, Kathleen D; Hamill, John D

    2016-05-01

    Transgenic plants of Nicotiana tabacum L. homozygous for an RNAi construct designed to silence ornithine decarboxylase (ODC) had significantly lower concentrations of nicotine and nornicotine, but significantly higher concentrations of anatabine, compared with vector-only controls. Silencing of ODC also led to significantly reduced concentrations of polyamines (putrescine, spermidine and spermine), tyramine and phenolamides (caffeoylputrescine and dicaffeoylspermidine) with concomitant increases in concentrations of amino acids ornithine, arginine, aspartate, glutamate and glutamine. Root transcript levels of S-adenosyl methionine decarboxylase, S-adenosyl methionine synthase and spermidine synthase (polyamine synthesis enzymes) were reduced compared with vector controls, whilst transcript levels of arginine decarboxylase (putrescine synthesis), putrescine methyltransferase (nicotine production) and multi-drug and toxic compound extrusion (alkaloid transport) proteins were elevated. In contrast, expression of two other key proteins required for alkaloid synthesis, quinolinic acid phosphoribosyltransferase (nicotinic acid production) and a PIP-family oxidoreductase (nicotinic acid condensation reactions), were diminished in roots of odc-RNAi plants relative to vector-only controls. Transcriptional and biochemical differences associated with polyamine and alkaloid metabolism were exacerbated in odc-RNAi plants in response to different forms of shoot damage. In general, apex removal had a greater effect than leaf wounding alone, with a combination of these injury treatments producing synergistic responses in some cases. Reduced expression of ODC appeared to have negative effects upon plant growth and vigour with some leaves of odc-RNAi lines being brittle and bleached compared with vector-only controls. Together, results of this study demonstrate that ornithine decarboxylase has important roles in facilitating both primary and secondary metabolism in Nicotiana. PMID

  12. A coenzyme-independent decarboxylase/oxygenase cascade for the efficient synthesis of vanillin.

    PubMed

    Furuya, Toshiki; Miura, Misa; Kino, Kuniki

    2014-10-13

    Vanillin is one of the most widely used flavor compounds in the world as well as a promising versatile building block. The biotechnological production of vanillin from plant-derived ferulic acid has attracted much attention as a new alternative to chemical synthesis. One limitation of the known metabolic pathway to vanillin is its requirement for expensive coenzymes. Here, we developed a novel route to vanillin from ferulic acid that does not require any coenzymes. This artificial pathway consists of a coenzyme-independent decarboxylase and a coenzyme-independent oxygenase. When Escherichia coli cells harboring the decarboxylase/oxygenase cascade were incubated with ferulic acid, the cells efficiently synthesized vanillin (8.0 mM, 1.2 g L(-1) ) via 4-vinylguaiacol in one pot, without the generation of any detectable aromatic by-products. The efficient method described here might be applicable to the synthesis of other high-value chemicals from plant-derived aromatics. PMID:25164030

  13. X-ray Crystallographic Analysis of α-Ketoheterocycle Inhibitors Bound to a Humanized Variant of Fatty Acid Amide Hydrolase

    PubMed Central

    Mileni, Mauro; Garfunkle, Joie; Ezzili, Cyrine; Kimball, F. Scott; Cravatt, Benjamin F.; Stevens, Raymond C.; Boger, Dale L.

    2009-01-01

    Three cocrystal X-ray structures of the α-ketoheterocycle inhibitors 3–5 bound to a humanized variant of fatty acid amide hydrolase (FAAH) are disclosed and comparatively discussed alongside those of 1 (OL-135) and its isomer 2. These five X-ray structures systematically probe each of the three active site regions key to substrate or inhibitor binding: (1) the conformationally mobile acyl chain-binding pocket and membrane access channel responsible for fatty acid amide substrate and inhibitor acyl chain binding, (2) the atypical active site catalytic residues and surrounding oxyanion hole that covalently binds the core of the α-ketoheterocycle inhibitors captured as deprotonated hemiketals mimicking the tetrahedral intermediate of the enzyme catalyzed reaction, and (3) the cytosolic port and its uniquely important imbedded ordered water molecules and a newly identified anion binding site. The detailed analysis of their key active site interactions and their implications on the interpretation of the available structure–activity relationships are discussed providing important insights for future design. PMID:19924997

  14. X-ray Crystallographic Analysis of [alpha]-Ketoheterocycle Inhibitors Bound to a Humanized Variant of Fatty Acid Amide Hydrolase

    SciTech Connect

    Mileni, Mauro; Garfunkle, Joie; Ezzili, Cyrine; Kimball, F.Scott; Cravatt, Benjamin F.; Stevens, Raymond C.; Boger, Dale L.

    2010-11-03

    Three cocrystal X-ray structures of the {alpha}-ketoheterocycle inhibitors 3-5 bound to a humanized variant of fatty acid amide hydrolase (FAAH) are disclosed and comparatively discussed alongside those of 1 (OL-135) and its isomer 2. These five X-ray structures systematically probe each of the three active site regions key to substrate or inhibitor binding: (1) the conformationally mobile acyl chain-binding pocket and membrane access channel responsible for fatty acid amide substrate and inhibitor acyl chain binding, (2) the atypical active site catalytic residues and surrounding oxyanion hole that covalently binds the core of the {alpha}-ketoheterocycle inhibitors captured as deprotonated hemiketals mimicking the tetrahedral intermediate of the enzyme-catalyzed reaction, and (3) the cytosolic port and its uniquely important imbedded ordered water molecules and a newly identified anion binding site. The detailed analysis of their key active site interactions and their implications on the interpretation of the available structure-activity relationships are discussed providing important insights for future design.

  15. Novel Bifunctional Quinolonyl Diketo Acid Derivatives as HIV-1 Integrase Inhibitors: Design, Synthesis, Biological Activities and Mechanism of Action

    PubMed Central

    Di Santo, Roberto; Costi, Roberta; Roux, Alessandra; Artico, Marino; Lavecchia, Antonio; Marinelli, Luciana; Novellino, Ettore; Palmisano, Lucia; Andreotti, Mauro; Amici, Roberta; Galluzzo, Clementina Maria; Nencioni, Lucia; Palamara, Anna Teresa; Pommier, Yves; Marchand, Christophe

    2008-01-01

    The virally encoded integrase protein is an essential enzyme in the life cycle of the HIV-1 virus and represents an attractive and validated target in the development of therapeutics against HIV infection. Drugs that selectively inhibit this enzyme, when used in combination with inhibitors of reverse transcriptase and protease, are believed to be highly effective in suppressing the viral replication. Among the HIV-1 integrase inhibitors, the β-diketo acids (DKAs) represent a major lead for anti-HIV-1drug development. In this study, novel bifunctional quinolonyl diketo acid derivatives were designed, synthesized and tested for their inhibitory ability against HIV-1 integrase. The compounds are potent inhibitors of integrase activity. Particularly, derivative 8 is a potent IN inhibitor for both steps of the reaction (3′-processing and strand transfer) and exhibits both high antiviral activity against HIV-1 infected cells and low cytotoxicity. Molecular modeling studies provide a plausible mechanism of action, which is consistent with ligand SARs and enzyme photo-crosslinking experiments. PMID:16539381

  16. Ornithine Decarboxylase, Polyamines, and Pyrrolizidine Alkaloids in Senecio and Crotalaria

    PubMed Central

    Birecka, Helena; Birecki, Mieczyslaw; Cohen, Eric J.; Bitonti, Alan J.; McCann, Peter P.

    1988-01-01

    When tested for ornithine and arginine decarboxylases, pyrrolizidine alkaloid-bearing Senecio riddellii, S. longilobus (Compositae), and Crotalaria retusa (Leguminosae) plants exhibited only ornithine decarboxylase activity. This contrasts with previous studies of four species of pyrrolizidine alkaloid-bearing Heliotropium (Boraginaceae) in which arginine decarboxylase activity was very high relative to that of ornithine decarboxylase. Unlike Heliotropium angiospermum and Heliotropium indicum, in which endogenous arginine was the only detectable precursor of putrescine channeled into pyrrolizidines, in the species studied here—using difluoromethylornithine and difluoromethylarginine as the enzyme inhibitors—endogenous ornithine was the main if not the only precursor of putrescine converted into the alkaloid aminoalcohol moiety. In S. riddellii and C. retusa at flowering, ornithine decarboxylase activity was present mainly in leaves, especially the young ones. However, other very young organs such as inflorescence and growing roots exhibited much lower or very low activities; the enzyme activity in stems was negligible. There was no correlation between the enzyme activity and polyamine or alkaloid content in either species. In both species only free polyamines were detected except for C. retusa roots and inflorescence—with relatively very high levels of these compounds—in which conjugated putrescine, spermidine, and spermine were also found; agmatine was not identified by HPLC in any plant organ except for C. retusa roots with rhizobial nodules. Organ- or age-dependent differences in the polyamine levels were small or insignificant. The highest alkaloid contents were found in young leaves and inflorescence. PMID:16665870

  17. Hydroxamic Acid and Benzoic Acid-Based STAT3 Inhibitors Suppress Human Glioma and Breast Cancer Phenotypes In Vitro and In Vivo.

    PubMed

    Yue, Peibin; Lopez-Tapia, Francisco; Paladino, David; Li, Yifei; Chen, Chih-Hong; Namanja, Andrew T; Hilliard, Tyvette; Chen, Yuan; Tius, Marcus A; Turkson, James

    2016-02-01

    STAT3 offers an attractive target for cancer therapy, but small-molecule inhibitors with appealing pharmacologic properties have been elusive. Here, we report hydroxamic acid-based and benzoic acid-based inhibitors (SH5-07 and SH4-54, respectively) with robust bioactivity. Both inhibitors blocked STAT3 DNA-binding activity in vitro and in human glioma, breast, and prostate cancer cells and in v-Src-transformed murine fibroblasts. STAT3-dependent gene transcription was blocked along with Bcl-2, Bcl-xL, Mcl-1, cyclin D1, c-Myc, and survivin expression. Nuclear magnetic resonance analysis of STAT3-inhibitor complexes defined interactions with the SH2 and DNA-binding domains of STAT3. Ectopic expression of the SH2 domain in cells was sufficient to counter the STAT3-inhibitory effects of SH4-54. Neither compound appreciably affected STAT1 or STAT5 DNA-binding activities, STAT3-independent gene transcription, or activation of a panel of oncogenic kinases in malignant cells. Each compound decreased the proliferation and viability of glioma, breast, and prostate cancer cells and v-Src-transformed murine fibroblasts harboring constitutively active STAT3. Further, in mouse xenograft models of glioma and breast cancer, administration of SH5-07 or SH4-54 effectively inhibited tumor growth. Our results offer preclinical proof of concept for SH5-07 and SH4-54 as candidates for further development as cancer therapeutics. PMID:26088127

  18. Binding and Inactivation Mechanism of a Humanized Fatty Acid Amide Hydrolase by [alpha]-Ketoheterocycle Inhibitors Revealed from Cocrystal Structures

    SciTech Connect

    Mileni, Mauro; Garfunkle, Joie; DeMartino, Jessica K.; Cravatt, Benjamin F.; Boger, Dale L.; Stevens, Raymond C.

    2010-08-17

    The cocrystal X-ray structures of two isomeric {alpha}-ketooxazole inhibitors (1 (OL-135) and 2) bound to fatty acid amide hydrolase (FAAH), a key enzymatic regulator of endocannabinoid signaling, are disclosed. The active site catalytic Ser241 is covalently bound to the inhibitors electrophilic carbonyl groups, providing the first structures of FAAH bound to an inhibitor as a deprotonated hemiketal mimicking the enzymatic tetrahedral intermediate. The work also offers a detailed view of the oxyanion hole and an exceptional 'in-action' depiction of the unusual Ser-Ser-Lys catalytic triad. These structures capture the first picture of inhibitors that span the active site into the cytosolic port providing new insights that help to explain FAAH's interaction with substrate leaving groups and their role in modulating inhibitor potency and selectivity. The role for the activating central heterocycle is clearly defined and distinguished from that observed in prior applications with serine proteases, reconciling the large electronic effect of attached substituents found unique to this class of inhibitors with FAAH. Additional striking active site flexibility is seen upon binding of the inhibitors, providing insights into the existence of a now well-defined membrane access channel with the disappearance of a spatially independent portion of the acyl chain-binding pocket. Finally, comparison of the structures of OL-135 (1) and its isomer 2 indicates that they bind identically to FAAH, albeit with reversed orientations of the central activating heterocycle, revealing that the terminal 2-pyridyl substituent and the acyl chain phenyl group provide key anchoring interactions and confirming the distinguishing role of the activating oxazole.

  19. Valoniopsis pachynema Extract as a Green Inhibitor for Corrosion of Brass in 0.1 N Phosphoric Acid Solution

    NASA Astrophysics Data System (ADS)

    Selva Kumar, R.; Chandrasekaran, V.

    2016-04-01

    The effect of marine alga Valoniopsis pachynema extract on corrosion inhibition of brass in phosphoric acid was investigated by weight-loss method, potentiodynamic polarization, and electrochemical impedance spectroscopy studies. The inhibition efficiency is found to increase with increasing concentration of extract and decreases with rise in temperature. The activation energy, thermodynamic parameters (free energy, enthalpy, and entropy change) and kinetic parameters (rate constant and half-life) for inhibition process were calculated. These thermodynamic and kinetic parameters indicate a strong interaction between the inhibitor and the brass surface. The inhibition is assumed to occur via adsorption of inhibitor molecules on brass surface, which obeys Temkin adsorption isotherm. The adsorption of inhibitor on the brass surface is exothermic, physical, and spontaneous, and follows first-order kinetics. The polarization measurements showed that the inhibitor behaves as a mixed type inhibitor and the higher inhibition surface coverage on the brass was predicted. Inhibition efficiency values were found to show good trend with weight-loss method, potentiodynamic polarization, and electrochemical impedance spectroscopy studies. Surface study techniques (FT-IR and SEM) were carried out to ascertain the inhibitive nature of the algal extract on the brass surface.

  20. Determination of human serum alpha1-acid glycoprotein and albumin binding of various marketed and preclinical kinase inhibitors.

    PubMed

    Zsila, Ferenc; Fitos, Ilona; Bencze, Gyula; Kéri, György; Orfi, László

    2009-01-01

    There are about 380 protein kinase inhibitors in drug development as of today and 15 drugs have been marketed already for the treatment of cancer. This time 139 validated kinase targets are in the focus of drug research of pharmaceutical companies and big efforts are made for the development of new, druglike kinase inhibitors. Plasma protein binding is an important factor of the ADME profiling of a drug compound. Human serum albumin (HSA) and alpha(1)-acid glycoprotein (AAG) are the most relevant drug carriers in blood plasma. Since previous literature data indicated that AAG is the principal plasma binding component of some kinase inhibitors the present work focuses on the comprehensive evaluation of AAG binding of a series of marketed and experimental kinase inhibitors by using circular dichroism (CD) spectroscopy approach. HSA binding was also evaluated by affinity chromatography. Protein binding interactions of twenty-six kinase inhibitors are characterized. The contribution of AAG and HSA binding data to the pharmacokinetic profiles of the investigated therapeutic agents is discussed. Structural, biological and drug binding properties of AAG as well as the applicability of the CD method in studying drug-protein binding interactions are also briefly reviewed. PMID:19519376

  1. Glutamate decarboxylase from barley embryos and roots. General properties and the occurrence of three enzymic forms.

    PubMed Central

    Inatomi, K; Slaughter, J C

    1975-01-01

    Glutamate decarboxylase in extracts of barley has a Km value for L-glutamate of 22 mM and is activated by the addition of pyridoxal phosphate by up to 3.5 times. Sucrose-density-gradient experiments indicate the presence of two enzyme forms with molecular weights 256000 and 120000. The lower-molecular-weight form appears to be relatively inactive and spontaneously associates to the higher-molecular-weight form on storage. The enzyme is inhibited by thiol reagents and the distribution of activity on density gradients is altered in favour of the lower-molecular-weight form by the presence of 2-mercaptoethanol. After removal of the 2-mercaptoethanol spontaneous association to the higher-molecular-weight form occurs. The presence of oxygen in the extraction buffer and in the water during imbibition leads to a relative increase in the higher-molecular-weight form compared with situations where oxygen is excluded. In contrast, glutamate decarboxylase in extracts of 3-day-old barley roots has a Km value for L-glutamate of 3.1 mM and is activated up to 10% by addition of pyridoxal phosphate. The root enzyme occurs as a single species with molecular weight 310000 and this is unaffected by 2-mercaptoethanol although thiol reagents do act as weak inhibitors. The molecular weight is also unaffected by the presence or absence of oxygen in the extraction buffers. PMID:1167156

  2. Analogs of the antituberculous agent pyrazinamide are competitive inhibitors of NADPH binding to M. tuberculosis fatty acid synthase I.

    PubMed

    Sayahi, Halimah; Pugliese, Kaitlin M; Zimhony, Oren; Jacobs, William R; Shekhtman, Alexander; Welch, John T

    2012-11-01

    Analogs of pyrazinamide (=pyrazine-2-carboxamide; PZA), an essential component of short-course antituberculous chemotherapy, such as 5-chloropyrazinamide (5-Cl-PZA) act as competitive inhibitors of NADPH binding to purified mycobacterial fatty acid synthase I (FAS I) as shown by Saturation Transfer Difference (STD) NMR studies. In addition, pyrazinoic acid esters (POE) and 5-Cl-POE reversibly bind to FAS I with the relatively greater affinity of longer-chain esters for FAS I, clear from the STD amplification factors. The competitive binding of PZA and 5-Cl-PZA clearly illustrates that both agents bind FAS. In contrast to PZA, at low NADPH concentrations 5-Cl-PZA is a cooperative inhibitor of NADPH binding. PMID:23161636

  3. Rhabdovirus-induced apoptosis in a fish cell line is inhibited by a human endogenous acid cysteine proteinase inhibitor.

    PubMed Central

    Björklund, H V; Johansson, T R; Rinne, A

    1997-01-01

    To determine the mechanisms of cell death in rhabdovirus-infected cells, we studied the infection of the epithelial papilloma of carp cell line with spring viremia of carp virus. Studies using electron microscopy, confocal microscopy, and agarose gel electrophoresis revealed changes in cell morphology and DNA fragmentation indicative of apoptosis. The virus-induced apoptosis was inhibited in cells treated with a human endogenous acid cysteine proteinase inhibitor. PMID:9188644

  4. Nitrogen-15 NMR spectroscopy of the catalytic-triad histidine of a serine protease in peptide boronic acid inhibitor complexes.

    PubMed

    Bachovchin, W W; Wong, W Y; Farr-Jones, S; Shenvi, A B; Kettner, C A

    1988-10-01

    15N NMR spectroscopy was used to examine the active-site histidyl residue of alpha-lytic protease in peptide boronic acid inhibitor complexes. Two distinct types of complexes were observed: (1) Boronic acids that are analogues of substrates form complexes in which the active-site imidazole ring is protonated and both imidazole N-H protons are strongly hydrogen bonded. With the better inhibitors of the class this arrangement is stable over the pH range 4.0-10.5. The results are consistent with a putative tetrahedral intermediate like complex involving a negatively charged, tetrahedral boron atom covalently bonded to O gamma of the active-site serine. (2) Boronic acids that are not substrate analogues form complexes in which N epsilon 2 of the active-site histidine is covalently bonded to the boron atom of the inhibitor. The proton bound to N delta 1 of the histidine in these histidine-boronate adducts remains strongly hydrogen bonded, presumably to the active-site aspartate. Benzeneboronic acid, which falls in this category, forms an adduct with histidine. In both types of complexes the N-H protons of His-57 exchange unusually slowly as evidenced by the room temperature visibility of the low-field 1H resonances and the 15N-H spin couplings. These results, coupled with the kinetic data of the preceding paper [Kettner, C. A., Bone, R., Agard, D. A., & Bachovchin, W. W. (1988) Biochemistry (preceding paper in this issue)], indicate that occupancy of the specificity subsites may be required to fully form the transition-state binding site. The significance of these findings for understanding inhibitor binding and the catalytic mechanism of serine proteases is discussed. PMID:3207700

  5. Nitrogen-15 NMR spectroscopy of the catalytic-triad histidine of a serine protease in peptide boronic acid inhibitor complexes

    SciTech Connect

    Bachovchin, W.W.; Wong, W.Y.L.; Farr-Jones, S. ); Shenvi, A.B.; Kettner, C.A. )

    1988-10-04

    {sup 15}N NMR spectroscopy was used to examine the active-site histidyl residue of {alpha}-lytic protease in peptide boronic acid inhibitor complexes. Two distinct types of complexes were observed: (1) Boronic acids that are analogues of substrates form complexes in which the active-site imidazole ring is protonated and both imidazole N-H protons are strongly hydrogen bonded. (2) Boronic acids that are not substrate analogues form complexes in which N{sup {epsilon}2} of the active-site histidine is covalently bonded to the boron atom of the inhibitor. The proton bound to N{sup {delta}1} of the histidine in these histidine-boronate adducts remains strongly hydrogen bonded, presumably to the active-site aspartate. In both types of complexes the N-H protons of His-57 exchange unusually slowly as evidenced by the room temperature visibility of the low-field {sup 1}H resonances and the {sup 15}N-H spin couplings. These results indicate that occupancy of the specificity subsites may be required to fully form the transition-state binding site. The significance of these findings for understanding inhibitor binding and the catalytic mechanism of serine proteases is discussed.

  6. Biological inhibitor abatement and ethanol fermentation of sugars from dilute acid-pretreated rice hulls

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fermentation inhibitors arise from lignin, hemicellulose, and degraded sugar during pretreatment of lignocellulosic biomass. Use of a microbe has been explored for abatement of pretreated biomass in which fermentation inhibitors, if left untreated, can complicate microbial conversion of biomass to f...

  7. In silico Analysis for Predicting Fatty Acids of Black Cumin Oil as Inhibitors of P-Glycoprotein

    PubMed Central

    Ali, Babar; Jamal, Qazi Mohd. Sajid; Mir, Showkat R.; Shams, Saiba; Al-Wabel, Naser A.; Kamal, Mohammad A.

    2015-01-01

    Background: Black cumin oil is obtained from the seeds of Nigella sativa L. which belongs to family Ranunculaceae. The seed oil has been reported to possess antitumor, antioxidant, antibacterial, anti-inflammatory, hypoglycemic, central nervous system depressant, antioxidant, and immunostimulatory activities. These bioactivities have been attributed to the fixed oil, volatile oil, or their components. Seed oil consisted of 15 saturated fatty acids (17%) and 17 unsaturated fatty acids (82.9%). Long chain fatty acids and medium chain fatty acids have been reported to increase oral bioavailability of peptides, antibiotics, and other important therapeutic agents. In earlier studies, permeation enhancement and bioenhancement of drugs has been done with black cumin oil. Objective: In order to recognize the mechanism of binding of fatty acids to P-glycoprotein (P-gp), linoleic acid, oleic acid, margaric acid, cis-11, 14-eicosadienoic acid, and stearic acid were selected for in silico studies, which were carried out using AutoDock 4.2, based on the Lamarckian genetic algorithm principle. Materials and Methods: Template search with BLAST and HHblits has been performed against the SWISS-MODEL template library. The target sequence was searched with BLAST against the primary amino acid sequence of P-gp from Rattus norvegicus. Results: The amount of energy needed by linoleic acid, oleic acid, eicosadienoic acid, margaric acid, and stearic acid to bind with P-gp were found to be − 10.60, −10.48, −9.95, −11.92, and − 10.37 kcal/mol, respectively. The obtained data support that all the selected fatty acids have contributed to inhibit P-gp activity thereby enhances the bioavailability of drugs. Conclusion: This study plays a significant role in finding hot spots in P-gp and may offer the further scope of designing potent and specific inhibitors of P-gp. SUMMARY Generation of 3D structure of fatty acid compounds from Black cumin oil and 3D homology modeling of Rat P

  8. Histone deacetylase inhibitor valproic acid promotes the induction of pluripotency in mouse fibroblasts by suppressing reprogramming-induced senescence stress

    SciTech Connect

    Zhai, Yingying; Chen, Xi; Yu, Dehai; Li, Tao; Cui, Jiuwei; Wang, Guanjun; Hu, Ji-Fan; Li, Wei

    2015-09-10

    Histone deacetylase inhibitor valproic acid (VPA) has been used to increase the reprogramming efficiency of induced pluripotent stem cell (iPSC) from somatic cells, yet the specific molecular mechanisms underlying this effect is unknown. Here, we demonstrate that reprogramming with lentiviruses carrying the iPSC-inducing factors (Oct4-Sox2-Klf4-cMyc, OSKM) caused senescence in mouse fibroblasts, establishing a stress barrier for cell reprogramming. Administration of VPA protected cells from reprogramming-induced senescent stress. Using an in vitro pre-mature senescence model, we found that VPA treatment increased cell proliferation and inhibited apoptosis through the suppression of the p16/p21 pathway. In addition, VPA also inhibited the G2/M phase blockage derived from the senescence stress. These findings highlight the role of VPA in breaking the cell senescence barrier required for the induction of pluripotency. - Highlights: • Histone deacetylase inhibitor valproic acid enhances iPSC induction. • Valproic acid suppresses reprogramming-induced senescence stress. • Valproic acid downregulates the p16/p21 pathway in reprogramming. • This study demonstrates a new mechanistic role of valproic acid in enhancing reprogramming.

  9. Efficacy of phytic acid as an inhibitor of enzymatic and non-enzymatic browning in apple juice.

    PubMed

    Du, Yunjian; Dou, Siqi; Wu, Shengjun

    2012-11-15

    Browning decreases the commercial value of apple juice, and therefore colour preservation during processing and storage is the main objective of manufacturers. In this study, the efficacy of phytic acid as a browning inhibitor for use on apple juice was investigated. Browning of apple juice treated with phytic acid was monitored during processing and storage. 0.1 mM Phytic acid inhibited the polyphenol oxidase (PPO) from the apple juice by 99.2%. Consequently, the apple juice treated with phytic acid had significantly lower browning formation during processing and after 6 months of storage at room temperature compared with the control (p<0.05). Results indicate that this is a promising way to inhibit browning in apple juice. PMID:22868131

  10. Genetic analysis of the pyruvate decarboxylase reaction in yeast glycolysis.

    PubMed Central

    Schmitt, H D; Zimmermann, F K

    1982-01-01

    Six different pyruvate decarboxylase mutants of Saccharomyces cerevisiae were isolated. They belong to two unlinked complementation groups. Evidence is presented that one group is affected in a structural gene. The fact that five of the six mutants had residual pyruvate decarboxylase activity provided the opportunity for an intensive physiological characterization. It was shown that the loss of enzyme activity in vitro is reflected in a lower fermentation rate, an increased pyruvate secretion, and slower growth on a 2% glucose medium. The different effects of antimycin A on leaky mutants grown on ethanol versus the same mutants grown on glucose support the view that glucose induces some of the glycolytic enzymes, especially pyruvate decarboxylase. PMID:7050079

  11. Novel Type II Fatty Acid Biosynthesis (FAS II) Inhibitors as Multistage Antimalarial Agents

    PubMed Central

    Schrader, Florian C.; Glinca, Serghei; Sattler, Julia M.; Dahse, Hans-Martin; Afanador, Gustavo A.; Prigge, Sean T.; Lanzer, Michael; Mueller, Ann-Kristin; Klebe, Gerhard; Schlitzer, Martin

    2013-01-01

    Malaria is a potentially fatal disease caused by Plasmodium parasites and poses a major medical risk in large parts of the world. The development of new, affordable antimalarial drugs is of vital importance as there are increasing reports of resistance to the currently available therapeutics. In addition, most of the current drugs used for chemoprophylaxis merely act on parasites already replicating in the blood. At this point, a patient might already be suffering from the symptoms associated with the disease and could additionally be infectious to an Anopheles mosquito. These insects act as a vector, subsequently spreading the disease to other humans. In order to cure not only malaria but prevent transmission as well, a drug must target both the blood- and pre-erythrocytic liver stages of the parasite. P. falciparum (Pf) enoyl acyl carrier protein (ACP) reductase (ENR) is a key enzyme of plasmodial type II fatty acid biosynthesis (FAS II). It has been shown to be essential for liver-stage development of Plasmodium berghei and is therefore qualified as a target for true causal chemoprophylaxis. Using virtual screening based on two crystal structures of PfENR, we identified a structurally novel class of FAS inhibitors. Subsequent chemical optimization yielded two compounds that are effective against multiple stages of the malaria parasite. These two most promising derivatives were found to inhibit blood-stage parasite growth with IC50 values of 1.7 and 3.0 µm and lead to a more prominent developmental attenuation of liver-stage parasites than the gold-standard drug, primaquine. PMID:23341167

  12. Antiinflammatory Activity of a Novel Folic Acid Targeted Conjugate of the mTOR Inhibitor Everolimus.

    PubMed

    Lu, Yingjuan; Parker, Nikki; Kleindl, Paul J; Cross, Vicky A; Wollak, Kristin; Westrick, Elaine; Stinnette, Torian W; Gehrke, Mark A; Wang, Kevin; Santhapuram, Hari Krishna R; You, Fei; Hahn, Spencer J; Vaughn, Jeremy F; Klein, Patrick J; Vlahov, Iontcho R; Low, Philip S; Leamon, Christopher P

    2015-01-01

    Folate receptor (FR)-β has been identified as a promising target for antimacrophage and antiinflammatory therapies. In the present study, we investigated EC0565, a folic acid-derivative of everolimus, as a FR-specific inhibitor of the mammalian target of rapamycin (mTOR). Because of its amphiphilic nature, EC0565 was first evaluated for water solubility, critical micelle formation, stability in culture and FR-binding specificity. Using FR-expressing macrophages, the effect of EC0565 on mTOR signaling and cellular proliferation was studied. The pharmacokinetics, metabolism and bioavailability of EC0565 were studied in normal rats. The in vivo activity of EC0565 was assessed in rats with adjuvant arthritis, a "macrophage-rich" model with close resemblance to rheumatoid arthritis. EC0565 forms micellar aggregates in physiological buffers and demonstrates good water solubility as well as strong multivalent FR-binding capacity. EC0565 inhibited mTOR signaling in rat macrophages at nanomolar concentrations and induced G0/G1 cell cycle arrest in serum-starved RAW264.7 cells. Subcutaneously administered EC0565 in rats displayed good bioavailability and a relatively long half-life (~12 h). When given at 250 nmol/kg, EC0565 selectively inhibited proliferating cell nuclear antigen expression in thioglycollate-stimulated rat peritoneal cells. With limited dosing regimens, the antiarthritic activity of EC0565 was found superior to that of etanercept, everolimus and a nontargeted everolimus analog. The in vivo activity of EC0565 was also comparable to that of a folate-targeted aminopterin. Folate-targeted mTOR inhibition may be an effective way of suppressing activated macrophages in sites of inflammation, especially in nutrient-deprived conditions, such as in the arthritic joints. Further investigation and improvement upon the physical and biochemical properties of EC0565 are warranted. PMID:26181632

  13. Role of calcium in the modulation of ornithine decarboxylase activity in isolated pig granulosa cells in vitro

    PubMed Central

    Veldhuis, Johannes D.; Hammond, James M.

    1981-01-01

    We examined the role of Ca2+ in the control of basal and hormone-stimulated ornithine decarboxylase activity in isolated pig granulosa cells maintained under chemically defined conditions in vitro. Omission of Ca2+ from the incubation medium (measured Ca2+ concentration 5μm) decreased basal enzymic activity, and significantly (P<0.01) impaired the response to maximally stimulating doses of either lutropin or follitropin. No significant alteration occurred in the concentration of either gonadotropin required to elicit half-maximal effects. The addition of EGTA (1.27–2.0mm) to chelate residual extracellular Ca2+ further decreased hormone-induced rises in ornithine decarboxylase activity. Despite the presence of 1.27mm concentrations of extracellular Ca2+, the administration of presumptive Ca2+ antagonists, believed to impair trans-membrane Ca2+ influx [verapamil (10–100μm), nifedipine (1–100μm) or CoCl2 (1mm)] suppressed hormone-stimulated ornithine decarboxylase activity. The inhibitory effects of verapamil or of Ca2+ omission from the medium were not overcome by the phosphodiesterase inhibitor 3-isobutyl-1-methylxanthine (0.25mm), or by cholera toxin, or by an exogenously supplied cyclic AMP analogue, 8-bromo cyclic AMP. Conversely, micromolar concentrations of a putative bivalent-cation ionophore, A23187, increased significantly the stimulation of ornithine decarboxylase activity by saturating concentrations of lutropin or 8-bromo cyclic AMP. Thus the present observations implicate Ca2+ ions in the modulation of hormone action and cellular function in normal ovarian cells. PMID:6172119

  14. Parasite-specific inserts in the bifunctional S-adenosylmethionine decarboxylase/ornithine decarboxylase of Plasmodium falciparum modulate catalytic activities and domain interactions.

    PubMed Central

    Birkholtz, Lyn-Marie; Wrenger, Carsten; Joubert, Fourie; Wells, Gordon A; Walter, Rolf D; Louw, Abraham I

    2004-01-01

    Polyamine biosynthesis of the malaria parasite, Plasmodium falciparum, is regulated by a single, hinge-linked bifunctional PfAdoMetDC/ODC [ P. falciparum AdoMetDC (S-adenosylmethionine decarboxylase)/ODC (ornithine decarboxylase)] with a molecular mass of 330 kDa. The bifunctional nature of AdoMetDC/ODC is unique to Plasmodia and is shared by at least three species. The PfAdoMetDC/ODC contains four parasite-specific regions ranging in size from 39 to 274 residues. The significance of the parasite-specific inserts for activity and protein-protein interactions of the bifunctional protein was investigated by a single- and multiple-deletion strategy. Deletion of these inserts in the bifunctional protein diminished the corresponding enzyme activity and in some instances also decreased the activity of the neighbouring, non-mutated domain. Intermolecular interactions between AdoMetDC and ODC appear to be vital for optimal ODC activity. Similar results have been reported for the bifunctional P. falciparum dihydrofolate reductase-thymidylate synthase [Yuvaniyama, Chitnumsub, Kamchonwongpaisan, Vanichtanankul, Sirawaraporn, Taylor, Walkinshaw and Yuthavong (2003) Nat. Struct. Biol. 10, 357-365]. Co-incubation of the monofunctional, heterotetrameric approximately 150 kDa AdoMetDC domain with the monofunctional, homodimeric ODC domain (approximately 180 kDa) produced an active hybrid complex of 330 kDa. The hinge region is required for bifunctional complex formation and only indirectly for enzyme activities. Deletion of the smallest, most structured and conserved insert in the ODC domain had the biggest impact on the activities of both decarboxylases, homodimeric ODC arrangement and hybrid complex formation. The remaining large inserts are predicted to be non-globular regions located on the surface of these proteins. The large insert in AdoMetDC in contrast is not implicated in hybrid complex formation even though distinct interactions between this insert and the two domains

  15. Histone deacetylase inhibitor m-carboxycinnamic acid bis-hydroxamide attenuates plasminogen activator inhibitor-1 expression in human pleural mesothelial cells.

    PubMed

    Chung, Chi-Li; Sheu, Joen-Rong; Chen, Wei-Lin; Chou, Yung-Chen; Hsiao, Che-Jen; Hsiao, Shih-Hsin; Hsu, Ming-Jen; Cheng, Yu-Wen; Hsiao, George

    2012-04-01

    Plasminogen activator inhibitor-1 (PAI-1), primarily up-regulated by transforming growth factor (TGF)-β, is essential in the development of fibrosis. Histone deacetylase (HDAC) was shown to modulate gene expression and fibrogenesis in various tissues. However, the implications of HDAC in terms of PAI-1 expression and pleural fibrosis remain unclear. In this study, we examined the effects of m-carboxycinnamic acid bis-hydroxamide (CBHA), a hybrid-polar HDAC inhibitor, on the TGF-β1-induced expression of PAI-1 in a human pleural mesothelial cell line (MeT-5A). MeT-5A cells were treated with TGF-β1 in the presence or absence of CBHA. We assayed the expression and stability of PAI-1 mRNA and protein, PAI-1 promoter activity, the activation of Smad signaling, the protein-protein interactions of Smads with transcriptional cofactors Sp1 and coactivator p300, and the expression of the mRNA-stabilizing protein nucleolin. The results indicate that CBHA significantly inhibited TGF-β1-induced PAI-1 mRNA and protein expression, and attenuated PAI-1 promoter activity in MeT-5A cells. CBHA abrogated TGF-β1-induced Smad4 nuclear translocation, but not Smad2/3 activation. Furthermore, the association of Smad4 with p300, but not with Sp1, was disrupted by CBHA. Alternatively, CBHA suppressed TGF-β1-induced nucleolin expression, and thereby destabilized PAI-1 mRNA and decreased PAI-1 protein concentrations. These findings suggest that the inhibition of HDAC activity by CBHA may attenuate PAI-1 expression through the modulation of cellular signaling at multiple levels. Given the down-regulating effect of CBHA on PAI-1 expression, HDAC inhibitors should be tested further in animal models as potential therapeutic agents for pleural fibrosis. PMID:22033265

  16. Proton pump inhibitors

    MedlinePlus

    Proton pump inhibitors (PPIs) are medicines that work by reducing the amount of stomach acid made by glands in ... Proton pump inhibitors are used to: Relieve symptoms of acid reflux, or gastroesophageal reflux disease (GERD). This is a ...

  17. Dual role of alpha-acetolactate decarboxylase in Lactococcus lactis subsp. lactis.

    PubMed Central

    Goupil-Feuillerat, N; Cocaign-Bousquet, M; Godon, J J; Ehrlich, S D; Renault, P

    1997-01-01

    The alpha-acetolactate decarboxylase gene aldB is clustered with the genes for the branched-chain amino acids (BCAA) in Lactococcus lactis subsp. lactis. It can be transcribed with BCAA genes under isoleucine regulation or independently of BCAA synthesis under the control of its own promoter. The product of aldB is responsible for leucine sensibility under valine starvation. In the presence of more than 10 microM leucine, the alpha-acetolactate produced by the biosynthetic acetohydroxy acid synthase IlvBN is transformed to acetoin by AldB and, consequently, is not available for valine synthesis. AldB is also involved in acetoin formation in the 2,3-butanediol pathway, initiated by the catabolic acetolactate synthase, AlsS. The differences in the genetic organization, the expression, and the kinetics parameters of these enzymes between L. lactis and Klebsiella terrigena, Bacillus subtilis, or Leuconostoc oenos suggest that this pathway plays a different role in the metabolism in these bacteria. Thus, the alpha-acetolactate decarboxylase from L. lactis plays a dual role in the cell: (i) as key regulator of valine and leucine biosynthesis, by controlling the acetolactate flux by a shift to catabolism; and (ii) as an enzyme catalyzing the second step of the 2,3-butanediol pathway. PMID:9335274

  18. Crystal Structure and Substrate Specificity of Drosophila 3,4-Dihydroxyphenylalanine Decarboxylase

    SciTech Connect

    Han, Q.; Ding, H; Robinson, H; Christensen, B; Li, J

    2010-01-01

    3,4-Dihydroxyphenylalanine decarboxylase (DDC), also known as aromatic L-amino acid decarboxylase, catalyzes the decarboxylation of a number of aromatic L-amino acids. Physiologically, DDC is responsible for the production of dopamine and serotonin through the decarboxylation of 3,4-dihydroxyphenylalanine and 5-hydroxytryptophan, respectively. In insects, both dopamine and serotonin serve as classical neurotransmitters, neuromodulators, or neurohormones, and dopamine is also involved in insect cuticle formation, eggshell hardening, and immune responses. In this study, we expressed a typical DDC enzyme from Drosophila melanogaster, critically analyzed its substrate specificity and biochemical properties, determined its crystal structure at 1.75 Angstrom resolution, and evaluated the roles residues T82 and H192 play in substrate binding and enzyme catalysis through site-directed mutagenesis of the enzyme. Our results establish that this DDC functions exclusively on the production of dopamine and serotonin, with no activity to tyrosine or tryptophan and catalyzes the formation of serotonin more efficiently than dopamine. The crystal structure of Drosophila DDC and the site-directed mutagenesis study of the enzyme demonstrate that T82 is involved in substrate binding and that H192 is used not only for substrate interaction, but for cofactor binding of drDDC as well. Through comparative analysis, the results also provide insight into the structure-function relationship of other insect DDC-like proteins.

  19. Crystal Structure and Substrate Specificity of Drosophila 3,4-Dihydroxyphenylalanine Decarboxylase

    PubMed Central

    Han, Qian; Ding, Haizhen; Robinson, Howard; Christensen, Bruce M.; Li, Jianyong

    2010-01-01

    Background 3,4-Dihydroxyphenylalanine decarboxylase (DDC), also known as aromatic L-amino acid decarboxylase, catalyzes the decarboxylation of a number of aromatic L-amino acids. Physiologically, DDC is responsible for the production of dopamine and serotonin through the decarboxylation of 3,4-dihydroxyphenylalanine and 5-hydroxytryptophan, respectively. In insects, both dopamine and serotonin serve as classical neurotransmitters, neuromodulators, or neurohormones, and dopamine is also involved in insect cuticle formation, eggshell hardening, and immune responses. Principal Findings In this study, we expressed a typical DDC enzyme from Drosophila melanogaster, critically analyzed its substrate specificity and biochemical properties, determined its crystal structure at 1.75 Angstrom resolution, and evaluated the roles residues T82 and H192 play in substrate binding and enzyme catalysis through site-directed mutagenesis of the enzyme. Our results establish that this DDC functions exclusively on the production of dopamine and serotonin, with no activity to tyrosine or tryptophan and catalyzes the formation of serotonin more efficiently than dopamine. Conclusions The crystal structure of Drosophila DDC and the site-directed mutagenesis study of the enzyme demonstrate that T82 is involved in substrate binding and that H192 is used not only for substrate interaction, but for cofactor binding of drDDC as well. Through comparative analysis, the results also provide insight into the structure-function relationship of other insect DDC-like proteins. PMID:20098687

  20. Proteasome inhibitors.

    PubMed

    Teicher, Beverly A; Tomaszewski, Joseph E

    2015-07-01

    Proteasome inhibitors have a 20 year history in cancer therapy. The first proteasome inhibitor, bortezomib (Velcade, PS-341), a break-through multiple myeloma treatment, moved rapidly through development from bench in 1994 to first approval in 2003. Bortezomib is a reversible boronic acid inhibitor of the chymotrypsin-like activity of the proteasome. Next generation proteasome inhibitors include carfilzomib and oprozomib which are irreversible epoxyketone proteasome inhibitors; and ixazomib and delanzomib which are reversible boronic acid proteasome inhibitors. Two proteasome inhibitors, bortezomib and carfilzomib are FDA approved drugs and ixazomib and oprozomib are in late stage clinical trials. All of the agents are potent cytotoxics. The disease focus for all the proteasome inhibitors is multiple myeloma. This focus arose from clinical observations made in bortezomib early clinical trials. Later preclinical studies confirmed that multiple myeloma cells were indeed more sensitive to proteasome inhibitors than other tumor cell types. The discovery and development of the proteasome inhibitor class of anticancer agents has progressed through a classic route of serendipity and scientific investigation. These agents are continuing to have a major impact in their treatment of hematologic malignancies and are beginning to be explored as potential treatment agent for non-cancer indications. PMID:25935605

  1. Boron-11 pure quadrupole resonance investigation of peptide boronic acid inhibitors bound to alpha-lytic protease.

    PubMed

    Ivanov, Dmitri; Bachovchin, William W; Redfield, Alfred G

    2002-02-01

    Pure quadrupole resonance is a potentially useful spectroscopic approach to study the coordination of quadrupolar nuclei in biological systems. We used a field-cycling NMR method to observe boron pure quadrupole resonance of two peptide boronic acid inhibitors bound to alpha-lytic protease. The method is similar to our earlier field-cycling experiment [Ivanov, D., and Redfield, A. R. (1998) Z. Naturforsch. A 53, 269-272] but uses a simple Hartmann-Hahn transfer from proton to (11)B before field cycle and direct (11)B observe after it. Pure quadrupole resonance is sensitive to the boron coordination geometry. For example, trigonal boron in neutral phenylboronic acid, which was used as a model compound, resonates at 1450 kHz, while the resonance of the tetrahedral phenylboronic acid anion appears at approximately 600 kHz. In the complex of the MeOSuc-Ala-Ala-Pro-boroVal inhibitor with the enzyme the quadrupole resonance signal was observed at 600-650 kHz, which indicates tetrahedral boron coordination in the active site. The quadrupole frequency of the MeOSuc-Ala-Ala-Pro-boroPhe enzyme-inhibitor complex, in which a boron-histidine bond is known to be formed, was found to be the same within experimental error as in the MeOSuc-Ala-Ala-Pro-boroVal enzyme-inhibitor adduct, suggesting that the boron coordination geometry in the enzyme-MeOSuc-Ala-Ala-Pro-boroPhe adduct is also close to tetrahedral. PMID:11814352

  2. Eco-Friendly Inhibitors for Copper Corrosion in Nitric Acid: Experimental and Theoretical Evaluation

    NASA Astrophysics Data System (ADS)

    Savita; Mourya, Punita; Chaubey, Namrata; Singh, V. K.; Singh, M. M.

    2016-02-01

    The inhibitive performance of Vitex negundo, Adhatoda vasica, and Saraka asoka leaf extracts on corrosion of copper in 3M HNO3 solution was investigated using gravimetric, potentiodynamic polarization, and electrochemical impedance spectroscopic techniques. Potentiodynamic polarization studies indicated that these extracts act as efficient and predominantly cathodic mixed inhibitor. Thermodynamic parameters revealed that the adsorption of these inhibitors on copper surface was spontaneous, controlled by physiochemical processes and occurred according to the Langmuir adsorption isotherm. AFM examination of copper surface confirmed that the inhibitor prevented corrosion by forming protective layer on its surface. The correlation between inhibitive effect and molecular structure was ascertained by density functional theory data.

  3. S-Farnesyl-Thiopropionic Acid Triazoles as Potent Inhibitors of Isoprenylcysteine Carboxyl Methyltransferase

    PubMed Central

    2011-01-01

    We report the design and synthesis of novel FTPA-triazole compounds as potent inhibitors of isoprenylcysteine carboxyl methyltransferase (Icmt), through a focus on thioether and isoprenoid mimetics. These mimetics were coupled utilizing a copper-assisted cycloaddition to assemble the potential inhibitors. Using the resulting triazole from the coupling as an isoprenyl mimetic resulted in the biphenyl-substituted FTPA triazole 10n. This lipid-modified analogue is a potent inhibitor of Icmt (IC50 = 0.8 ± 0.1 μM; calculated Ki = 0.4 μM). PMID:22754607

  4. FcWRKY70, a WRKY protein of Fortunella crassifolia, functions in drought tolerance and modulates putrescine synthesis by regulating arginine decarboxylase gene.

    PubMed

    Gong, Xiaoqing; Zhang, Jingyan; Hu, Jianbing; Wang, Wei; Wu, Hao; Zhang, Qinghua; Liu, Ji-Hong

    2015-11-01

    WRKY comprises a large family of transcription factors in plants, but most WRKY members are still poorly understood. In this study, we report functional characterization of a Group III WRKY gene (FcWRKY70) from Fortunella crassifolia. FcWRKY70 was greatly induced by drought and abscisic acid, but slightly or negligibly by salt and cold. Overexpression of FcWRKY70 in tobacco (Nicotiana nudicaulis) and lemon (Citrus lemon) conferred enhanced tolerance to dehydration and drought stresses. Transgenic tobacco and lemon exhibited higher expression levels of ADC (arginine decarboxylase), and accumulated larger amount of putrescine in comparison with wild type (WT). Treatment with D-arginine, an inhibitor of ADC, caused transgenic tobacco plants more sensitive to dehydration. Knock-down of FcWRKY70 in kumquat down-regulated ADC abundance and decreased putrescine level, accompanied by compromised dehydration tolerance. The promoter region of FcADC contained two W-box elements, which were shown to be interacted with FcWRKY70. Taken together, our data demonstrated that FcWRKY70 functions in drought tolerance by, at least partly, promoting production of putrescine via regulating ADC expression. PMID:25808564

  5. Oral putrescine restores virulence of ornithine decarboxylase-deficient Leishmania donovani in mice

    PubMed Central

    Olenyik, Tamara; Gilroy, Caslin; Ullman, Buddy

    2011-01-01

    Administration of putrescine as a 1% solution in the drinking water ameliorated the profound loss of virulence exhibited by ornithine decarboxylase (ODC) deficient Leishmania donovani in mice. Furthermore, supplying α-difluoromethylornithine, an ODC inhibitor, at 2% in the drinking water reduced but did not eliminate infection with wild type L. donovani in the mouse model. Taken collectively, these findings: 1) demonstrate that oral putrescine can access the phagolysosome of macrophages in which the parasite resides in mice; 2) establish that the loss of virulence due to the Δodc lesion is a consequence of the inability of the mutant parasite to synthesize sufficient polyamines de novo; 3) imply that the L. donovani amastigote cannot access host polyamines in sufficient amounts for survival and growth; 4) and validate ODC as a drug target, although oral administration of DFMO is an unlikely therapeutic paradigm for visceral leishmaniasis. PMID:21182873

  6. Suppression of ornithine decarboxylase promotes osteogenic differentiation of human bone marrow-derived mesenchymal stem cells.

    PubMed

    Tsai, Yo-Hsian; Lin, Kuan-Lian; Huang, Yuan-Pin; Hsu, Yi-Chiang; Chen, Chung-Hwan; Chen, Yuhsin; Sie, Min-Hua; Wang, Gwo-Jaw; Lee, Mon-Juan

    2015-07-22

    Ornithine decarboxylase (ODC) is the rate-limiting enzyme for polyamine biosynthesis. Suppression of ODC by its irreversible inhibitor, α-difluoromethylornithine (DFMO), or by RNA interference through siRNA, enhanced osteogenic gene expression and alkaline phosphatase activity, and accelerated matrix mineralization of human bone marrow-derived mesenchymal stem cells (hBMSCs). Besides, adipogenic gene expression and lipid accumulation was attenuated, indicating that the enhanced osteogenesis was accompanied by down-regulation of adipogenesis when ODC was suppressed. A decrease in the intracellular polyamine content of hBMSCs during osteogenic induction was observed, suggesting that the level of endogenous polyamines is regulated during differentiation of hBMSCs. This study elucidates the role of polyamine metabolism in the lineage commitment of stem cells and provides a potential new indication for DFMO as bone-stimulating drug. PMID:26140984

  7. Effects of norflurazon, an inhibitor of carotenogenesis, on abscisic acid and xanthoxin in the caps of gravistimulated maize roots

    NASA Technical Reports Server (NTRS)

    Feldman, L. J.; Sun, P. S.

    1986-01-01

    Maize seeds were germinated in the dark in the presence of the carotenoid synthesis inhibitor norflurazon and the levels of abscisic acid, xanthoxin and total carotenoids were measured in the root cap and in the adjacent 1.5 mm segment. In norflurazon-treated roots abscisic acid levels were markedly reduced, but an increase occurred in the levels of xanthoxin, a compound structurally and physiologically similar to abscisic acid. In the cultivar of maize (Zea mays L. cv. Merit) used for this work, brief illumination of the root is required for gravitropic curving. Following illumination both control and norflurazon-treated roots showed normal gravitropic curvature; however, the rate of curvature was delayed in norflurazon-treated roots. Our data from norflurazon-treated roots are consistent with a role for xanthoxin in maize root gravitropism. The increase in xanthoxin in the presence of an inhibitor of carotenoid synthesis suggests that xanthoxin and abscisic acid originate, at least in part, via different metabolic pathways.

  8. TarO-specific inhibitors of wall teichoic acid biosynthesis restore β-lactam efficacy against methicillin-resistant staphylococci.

    PubMed

    Lee, Sang Ho; Wang, Hao; Labroli, Marc; Koseoglu, Sandra; Zuck, Paul; Mayhood, Todd; Gill, Charles; Mann, Paul; Sher, Xinwei; Ha, Sookhee; Yang, Shu-Wei; Mandal, Mihir; Yang, Christine; Liang, Lianzhu; Tan, Zheng; Tawa, Paul; Hou, Yan; Kuvelkar, Reshma; DeVito, Kristine; Wen, Xiujuan; Xiao, Jing; Batchlett, Michelle; Balibar, Carl J; Liu, Jenny; Xiao, Jianying; Murgolo, Nicholas; Garlisi, Charles G; Sheth, Payal R; Flattery, Amy; Su, Jing; Tan, Christopher; Roemer, Terry

    2016-03-01

    The widespread emergence of methicillin-resistant Staphylococcus aureus (MRSA) has dramatically eroded the efficacy of current β-lactam antibiotics and created an urgent need for new treatment options. We report an S. aureus phenotypic screening strategy involving chemical suppression of the growth inhibitory consequences of depleting late-stage wall teichoic acid biosynthesis. This enabled us to identify early-stage pathway-specific inhibitors of wall teichoic acid biosynthesis predicted to be chemically synergistic with β-lactams. We demonstrated by genetic and biochemical means that each of the new chemical series discovered, herein named tarocin A and tarocin B, inhibited the first step in wall teichoic acid biosynthesis (TarO). Tarocins do not have intrinsic bioactivity but rather demonstrated potent bactericidal synergy in combination with broad-spectrum β-lactam antibiotics against diverse clinical isolates of methicillin-resistant staphylococci as well as robust efficacy in a murine infection model of MRSA. Tarocins and other inhibitors of wall teichoic acid biosynthesis may provide a rational strategy to develop Gram-positive bactericidal β-lactam combination agents active against methicillin-resistant staphylococci. PMID:26962156

  9. Synthesis and QSAR of Fatty Acid Amide Hydrolase Inhibitors: Modulation at the N-Portion of Biphenyl-3-yl Alkylcarbamates

    PubMed Central

    Mor, Marco; Lodola, Alessio; Rivara, Silvia; Vacondio, Federica; Duranti, Andrea; Tontini, Andrea; Sanchini, Silvano; Piersanti, Giovanni; Clapper, Jason R.; King, Alvin R.; Tarzia, Giorgio; Piomelli, Daniele

    2013-01-01

    Alkylcarbamic acid biphenyl-3-yl esters are a class of fatty acid amide hydrolase (FAAH) inhibitors that comprises cyclohexylcarbamic acid 3′-carbamoylbiphenyl-3-yl ester (URB597), a compound with analgesic, anxiolytic-like and antidepressant-like properties in rat and mouse models. Here, we extended the structure-activity relationships (SARs) for this class of compounds by replacing the cyclohexyl ring of the parent compound cyclohexylcarbamic acid biphenyl-3-yl ester (URB524) (IC50, for FAAH = 63 nM) with a selected set of substituents of different size, shape, flexibility and lipophilicity. Docking experiments and Linear Interaction Energy (LIE) calculations indicated that the N-terminal group of O-arylcarbamates fits within the lipophilic region of the substrate-binding site, mimicking the arachidonoyl chain of anandamide. Significant potency improvements were observed for the β-naphthylmethyl derivative 4q (IC50 = 5.3 nM) and its 3′-carbamoylbiphenyl-3-yl ester 4z (URB880, IC50 = 0.63 nM), indicating that shape complementarity and hydrogen bonds are crucial to obtain highly potent inhibitors. PMID:18507372

  10. Novel 5alpha-reductase inhibitors: synthesis, structure-activity studies, and pharmacokinetic profile of phenoxybenzoylphenyl acetic acids.

    PubMed

    Salem, Ola I A; Frotscher, Martin; Scherer, Christiane; Neugebauer, Alexander; Biemel, Klaus; Streiber, Martina; Maas, Ruth; Hartmann, Rolf W

    2006-01-26

    Novel substituted benzoyl benzoic acids and phenylacetic acids 1-14 have been synthesized and evaluated for inhibition of rat and human steroid 5alpha-reductase isozymes 1 and 2. The compounds turned out to be potent and selective human type 2 enzyme inhibitors, exhibiting IC(50) values in the nanomolar range. The phenylacetic acid derivatives were more potent than the analogous benzoic acids. Bromination in the 4-position of the phenoxy moiety led to the strongest inhibitor in this class (12; IC(50) = 5 nM), which was equipotent to finasteride. Since oral absorption is essential for a potential drug, 12 was further examined. In the parallel artificial membrane permeation assay (PAMPA) it turned out to be a good permeator, whereas it was a medium permeator in Caco2 cells. After oral administration (40 mg/kg) to rats a high bioavailability and a biological half-life of 5.5 h were observed, making it a promising candidate for clinical evaluation. PMID:16420060

  11. Metabolic effects of inhibitors of two enzymes of the branched-chain amino acid pathway in Salmonella typhimurium.

    PubMed Central

    Epelbaum, S; Chipman, D M; Barak, Z

    1996-01-01

    The metabolic effects of inhibitors of two enzymes in the pathway for biosynthesis of branched-chain amino acids were examined in Salmonella typhimurium mutant strain TV105, expressing a single isozyme of acetohydroxy acid synthase (AHAS), AHAS isozyme II. One inhibitor was the sulfonylurea herbicide sulfometuron methyl (SMM), which inhibits this isozyme and AHAS of other organisms, and the other was N-isopropyl oxalylhydroxamate (IpOHA), which inhibits ketol-acid reductoisomerase (KARI). The effects of the inhibitors on growth, levels of several enzymes of the pathway, and levels of intermediates of the pathway were measured. The intracellular concentration of the AHAS substrate 2-ketobutyrate increased on addition of SMM, but a lack of correlation between increased ketobutyrate and growth inhibition suggests that the former is not the immediate cause of the latter. The levels of the keto acid precursor of valine, but not of the precursor of isoleucine, were drastically decreased by SMM, and valine, but not isoleucine, partially overcame SMM inhibition. This apparent stronger effect of SMM on the flux into the valine arm, as opposed to the isoleucine arm, of the branched-chain amino acid pathway is explained by the kinetics of the AHAS reaction, as well as by the different roles of pyruvate, ketobutyrate, and the valine precursor in metabolism. The organization of the pathway thus potentiates the inhibitory effect of SMM. IpOHA has strong initial effects at lower concentrations than does SMM and leads to increases both in the acetohydroxy acid substrates of KARI and, surprisingly, in ketobutyrate. Valine completely protected strain TV105 from IpOHA at the MIC. A number of explanations for this effect can be ruled out, so that some unknown arrangement of the enzymes involved must be suggested. IpOHA led to initial cessation of growth, with partial recovery after a time whose duration increased with the inhibitor concentration. The recovery is apparently due to

  12. Metabolic effects of inhibitors of two enzymes of the branched-chain amino acid pathway in Salmonella typhimurium.

    PubMed

    Epelbaum, S; Chipman, D M; Barak, Z

    1996-02-01

    The metabolic effects of inhibitors of two enzymes in the pathway for biosynthesis of branched-chain amino acids were examined in Salmonella typhimurium mutant strain TV105, expressing a single isozyme of acetohydroxy acid synthase (AHAS), AHAS isozyme II. One inhibitor was the sulfonylurea herbicide sulfometuron methyl (SMM), which inhibits this isozyme and AHAS of other organisms, and the other was N-isopropyl oxalylhydroxamate (IpOHA), which inhibits ketol-acid reductoisomerase (KARI). The effects of the inhibitors on growth, levels of several enzymes of the pathway, and levels of intermediates of the pathway were measured. The intracellular concentration of the AHAS substrate 2-ketobutyrate increased on addition of SMM, but a lack of correlation between increased ketobutyrate and growth inhibition suggests that the former is not the immediate cause of the latter. The levels of the keto acid precursor of valine, but not of the precursor of isoleucine, were drastically decreased by SMM, and valine, but not isoleucine, partially overcame SMM inhibition. This apparent stronger effect of SMM on the flux into the valine arm, as opposed to the isoleucine arm, of the branched-chain amino acid pathway is explained by the kinetics of the AHAS reaction, as well as by the different roles of pyruvate, ketobutyrate, and the valine precursor in metabolism. The organization of the pathway thus potentiates the inhibitory effect of SMM. IpOHA has strong initial effects at lower concentrations than does SMM and leads to increases both in the acetohydroxy acid substrates of KARI and, surprisingly, in ketobutyrate. Valine completely protected strain TV105 from IpOHA at the MIC. A number of explanations for this effect can be ruled out, so that some unknown arrangement of the enzymes involved must be suggested. IpOHA led to initial cessation of growth, with partial recovery after a time whose duration increased with the inhibitor concentration. The recovery is apparently due to

  13. Inhibiting the β-Lactamase of Mycobacterium tuberculosis (Mtb) with Novel Boronic Acid Transition-State Inhibitors (BATSIs).

    PubMed

    Kurz, Sebastian G; Hazra, Saugata; Bethel, Christopher R; Romagnoli, Chiara; Caselli, Emilia; Prati, Fabio; Blanchard, John S; Bonomo, Robert A

    2015-06-12

    BlaC, the single chromosomally encoded β-lactamase of Mycobacterium tuberculosis, has been identified as a promising target for novel therapies that rely upon β-lactamase inhibition. Boronic acid transition-state inhibitors (BATSIs) are a class of β-lactamase inhibitors which permit rational inhibitor design by combinations of various R1 and R2 side chains. To explore the structural determinants of effective inhibition, we screened a panel of 25 BATSIs to explore key structure-function relationships. We identified a cefoperazone analogue, EC19, which displayed slow, time-dependent inhibition against BlaC with a potency similar to that of clavulanate (Ki* of 0.65 ± 0.05 μM). To further characterize the molecular basis of inhibition, we solved the crystallographic structure of the EC19-BlaC(N172A) complex and expanded our analysis to variant enzymes. The results of this structure-function analysis encourage the design of a novel class of β-lactamase inhibitors, BATSIs, to be used against Mycobacterium tuberculosis. PMID:27622739

  14. A new dioxime corrosion inhibitor for the protection and conservation of copper: synthesis, characterization and evaluation in acidic chloride solution

    NASA Astrophysics Data System (ADS)

    Abu-Baker, Ahmad N.; Al-Qudah, Mahmoud A.

    2016-08-01

    This study aimed to investigate a new dioxime compound as a corrosion inhibitor for copper. The compound (4,6-dihydroxy benzene-1,3-dicarbaldehyde dioxime) was synthesized and characterized by nuclear magnetic resonance spectroscopy. Electrochemical impedance spectroscopy and potentiodynamic polarization measurements were used to compare the dioxime compound with benzotriazole for their effectiveness as corrosion inhibitors for copper in 0.1 M HCl solution. Fourier transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) were used to investigate the bonding mechanisms and morphological changes of the two inhibitors on the copper surface. The electrochemical techniques showed that the new dioxime compound was more effective than benzotriazole in inhibiting copper corrosion in the acidic chloride medium. The FTIR and SEM results indicated that the dioxime compound was able to coordinate with copper ions and formed a protective film on the copper surface. It was concluded that the new dioxime compound proved effectiveness to be used as a corrosion inhibitor for the protection and conservation of copper.

  15. Discovery of a Cyclic Boronic Acid β-Lactamase Inhibitor (RPX7009) with Utility vs Class A Serine Carbapenemases.

    PubMed

    Hecker, Scott J; Reddy, K Raja; Totrov, Maxim; Hirst, Gavin C; Lomovskaya, Olga; Griffith, David C; King, Paula; Tsivkovski, Ruslan; Sun, Dongxu; Sabet, Mojgan; Tarazi, Ziad; Clifton, Matthew C; Atkins, Kateri; Raymond, Amy; Potts, Kristy T; Abendroth, Jan; Boyer, Serge H; Loutit, Jeffrey S; Morgan, Elizabeth E; Durso, Stephanie; Dudley, Michael N

    2015-05-14

    The increasing dissemination of carbapenemases in Gram-negative bacteria has threatened the clinical usefulness of the β-lactam class of antimicrobials. A program was initiated to discover a new series of serine β-lactamase inhibitors containing a boronic acid pharmacophore, with the goal of finding a potent inhibitor of serine carbapenemase enzymes that are currently compromising the utility of the carbapenem class of antibacterials. Potential lead structures were screened in silico by modeling into the active sites of key serine β-lactamases. Promising candidate molecules were synthesized and evaluated in biochemical and whole-cell assays. Inhibitors were identified with potent inhibition of serine carbapenemases, particularly the Klebsiella pneumoniae carbapenemase (KPC), with no inhibition of mammalian serine proteases. Studies in vitro and in vivo show that RPX7009 (9f) is a broad-spectrum inhibitor, notably restoring the activity of carbapenems against KPC-producing strains. Combined with a carbapenem, 9f is a promising product for the treatment of multidrug resistant Gram-negative bacteria. PMID:25782055

  16. New coumarin derivative as an eco-friendly inhibitor of corrosion of mild steel in Acid medium.

    PubMed

    Al-Amiery, Ahmed A; Al-Majedy, Yasameen K; Kadhum, Abdul Amir H; Mohamad, Abu Bakar

    2015-01-01

    The anticorrosion ability of a synthesized coumarin, namely 2-(coumarin-4-yloxy)acetohydrazide (EFCI), for mild steel (MS) in 1 M hydrochloric acid solution has been studied using a weight loss method. The effect of temperature on the corrosion rate was investigated, and some thermodynamic parameters were calculated. The results indicated that inhibition efficiencies were enhanced with an increase in concentration of inhibitor and decreased with a rise in temperature. The IE value reaches 94.7% at the highest used concentration of the new eco-friendly inhibitor. The adsorption of inhibitor on MS surface was found to obey a Langmuir adsorption isotherm. Scanning electron microscopy (SEM) was performed on inhibited and uninhibited mild steel samples to characterize the surface. The Density Function theory (DFT) was employed for quantum-chemical calculations such as EHOMO (highest occupied molecular orbital energy), ELUMO (lowest unoccupied molecular orbital energy) and μ (dipole moment), and the obtained results were found to be consistent with the experimental findings. The synthesized inhibitor was characterized by Fourier transform infrared (FTIR) and nuclear magnetic resonance (NMR) spectroscopic studies. PMID:25551187

  17. Identification of Genes Conferring Tolerance to Lignocellulose-Derived Inhibitors by Functional Selections in Soil Metagenomes.

    PubMed

    Forsberg, Kevin J; Patel, Sanket; Witt, Evan; Wang, Bin; Ellison, Tyler D; Dantas, Gautam

    2016-01-01

    The production of fuels or chemicals from lignocellulose currently requires thermochemical pretreatment to release fermentable sugars. These harsh conditions also generate numerous small-molecule inhibitors of microbial growth and fermentation, limiting production. We applied small-insert functional metagenomic selections to discover genes that confer microbial tolerance to these inhibitors, identifying both individual genes and general biological processes associated with tolerance to multiple inhibitory compounds. Having screened over 248 Gb of DNA cloned from 16 diverse soil metagenomes, we describe gain-of-function tolerance against acid, alcohol, and aldehyde inhibitors derived from hemicellulose and lignin, demonstrating that uncultured soil microbial communities hold tremendous genetic potential to address the toxicity of pretreated lignocellulose. We recovered genes previously known to confer tolerance to lignocellulosic inhibitors as well as novel genes that confer tolerance via unknown functions. For instance, we implicated galactose metabolism in overcoming the toxicity of lignin monomers and identified a decarboxylase that confers tolerance to ferulic acid; this enzyme has been shown to catalyze the production of 4-vinyl guaiacol, a valuable precursor to vanillin production. These metagenomic tolerance genes can enable the flexible design of hardy microbial catalysts, customized to withstand inhibitors abundant in specific bioprocessing applications. PMID:26546427

  18. Identification of Genes Conferring Tolerance to Lignocellulose-Derived Inhibitors by Functional Selections in Soil Metagenomes

    PubMed Central

    Forsberg, Kevin J.; Patel, Sanket; Witt, Evan; Wang, Bin; Ellison, Tyler D.

    2015-01-01

    The production of fuels or chemicals from lignocellulose currently requires thermochemical pretreatment to release fermentable sugars. These harsh conditions also generate numerous small-molecule inhibitors of microbial growth and fermentation, limiting production. We applied small-insert functional metagenomic selections to discover genes that confer microbial tolerance to these inhibitors, identifying both individual genes and general biological processes associated with tolerance to multiple inhibitory compounds. Having screened over 248 Gb of DNA cloned from 16 diverse soil metagenomes, we describe gain-of-function tolerance against acid, alcohol, and aldehyde inhibitors derived from hemicellulose and lignin, demonstrating that uncultured soil microbial communities hold tremendous genetic potential to address the toxicity of pretreated lignocellulose. We recovered genes previously known to confer tolerance to lignocellulosic inhibitors as well as novel genes that confer tolerance via unknown functions. For instance, we implicated galactose metabolism in overcoming the toxicity of lignin monomers and identified a decarboxylase that confers tolerance to ferulic acid; this enzyme has been shown to catalyze the production of 4-vinyl guaiacol, a valuable precursor to vanillin production. These metagenomic tolerance genes can enable the flexible design of hardy microbial catalysts, customized to withstand inhibitors abundant in specific bioprocessing applications. PMID:26546427

  19. Potent α-amino-β-lactam carbamic acid ester as NAAA inhibitors. Synthesis and structure-activity relationship (SAR) studies.

    PubMed

    Nuzzi, Andrea; Fiasella, Annalisa; Ortega, Jose Antonio; Pagliuca, Chiara; Ponzano, Stefano; Pizzirani, Daniela; Bertozzi, Sine Mandrup; Ottonello, Giuliana; Tarozzo, Glauco; Reggiani, Angelo; Bandiera, Tiziano; Bertozzi, Fabio; Piomelli, Daniele

    2016-03-23

    4-Cyclohexylbutyl-N-[(S)-2-oxoazetidin-3-yl]carbamate (3b) is a potent, selective and systemically active inhibitor of intracellular NAAA activity, which produces profound anti-inflammatory effects in animal models. In the present work, we describe structure-activity relationship (SAR) studies on 3-aminoazetidin-2-one derivatives, which have led to the identification of 3b, and expand these studies to elucidate the principal structural and stereochemical features needed to achieve effective NAAA inhibition. Investigations on the influence of the substitution at the β-position of the 2-oxo-3-azetidinyl ring as well as on the effect of size and shape of the carbamic acid ester side chain led to the discovery of 3ak, a novel inhibitor of human NAAA that shows an improved physicochemical and drug-like profile relative to 3b. This favourable profile, along with the structural diversity of the carbamic acid chain of 3b, identify this compound as a promising new tool to investigate the potential of NAAA inhibitors as therapeutic agents for the treatment of pain and inflammation. PMID:26866968

  20. Amino Acid Thioester Derivatives: A Highly Promising Scaffold for the Development of Metallo-β-lactamase L1 Inhibitors

    PubMed Central

    2015-01-01

    In light of the biomedical significance of metallo-β-lactamases (MβLs), ten new mercaptoacetic acid thioester amino acid derivatives were synthesized and characterized. Biological activity assays indicated that all these synthesized compounds are very potent inhibitors of L1, exhibiting an IC50 value range of 0.018–2.9 μM and a Ki value range of 0.11–0.95 μM using cefazolin as substrate. Partial thioesters also showed effective inhibitory activities against NDM-1 and ImiS with an IC50 value range of 12–96 and 3.6–65 μM, respectively. Also, all these thioesters increased susceptibility of E. coli cells expressing L1 to cefazolin, indicated by a 2–4-fold reduction in MIC of the antibiotic. Docking studies revealed potential binding modes of the two most potent L1 inhibitors to the active site in which the carboxylate group interacts with both Zn(II) ions and Ser221. This work introduces a highly promising scaffold for the development of metallo-β-lactamase L1 inhibitors. PMID:26101570

  1. Effect of inhibitors of arachidonic acid metabolism on efflux of intracellular enzymes from skeletal muscle following experimental damage.

    PubMed Central

    Jackson, M J; Wagenmakers, A J; Edwards, R H

    1987-01-01

    The role of arachidonic acid metabolism in the efflux of intracellular enzymes from damaged skeletal muscle has been examined in vitro using inhibitors of cyclo-oxygenase and lipoxygenase enzymes. Damage to skeletal muscle induced by either calcium ionophore A23187 (25 microM) or dinitrophenol (1 mM) caused an increase in the efflux of prostaglandins E2 and F2 alpha together with a large efflux of intracellular creatine kinase. Use of a cyclo-oxygenase inhibitor completely prevented the efflux of prostaglandins, but had no effect on creatine kinase efflux. However, several agents having the ability to inhibit lipoxygenase enzymes dramatically reduced creatine kinase efflux following damage. These data suggest that a product or products of lipoxygenase enzymes may be mediators of the changes in plasma membrane integrity which permit efflux of intracellular enzymes as a consequence of skeletal muscle damage. PMID:3109374

  2. Ellagic acid and polyhydroxylated urolithins are potent catalytic inhibitors of human topoisomerase II: an in vitro study.

    PubMed

    Furlanetto, Valentina; Zagotto, Giuseppe; Pasquale, Riccardo; Moro, Stefano; Gatto, Barbara

    2012-09-12

    Ellagic acid (EA), a natural polyphenol abundant in fruits and common in our diet, is under intense investigation for its chemopreventive activity resulting from multiple effects. EA inhibits topoisomerase II, but the effects on the human enzyme of urolithins, its monolactone metabolites, are not known. Therefore, the action of several synthetic urolithins toward topoisomerases II was evaluated, showing that polyhydroxylated urolithins, EA, and EA-related compounds are potent inhibitors of the α and β isoforms of human topoisomerase II at submicromolar concentrations. Competition tests demonstrate a dose-dependent relationship between ATP and the inhibition of the enzyme. Docking experiments show that the active compounds bind the ATP pocket of the human enzyme, thus supporting the hypothesis that EA and polyhydroxylated urolithins act as ATP-competitive inhibitors of human topoisomerase II. PMID:22924519

  3. Design, synthesis, and biological activity of a potent inhibitor of the neuropeptidase N-acetylated alpha-linked acidic dipeptidase.

    PubMed

    Jackson, P F; Cole, D C; Slusher, B S; Stetz, S L; Ross, L E; Donzanti, B A; Trainor, D A

    1996-01-19

    A series of substituted phosphonate derivatives were designed and synthesized in order to study the ability of these compounds to inhibit the neuropeptidase N-acetylated alpha-linked acidic dipeptidase (NAALADase). The molecules were shown to act as inhibitors of the enzyme, with the most potent (compound 3) having a Ki of 0.275 nM. The potency of this compound is more than 1000 times greater than that of previously reported inhibitors of the enzyme. NAALADase is responsible for the catabolism of the abundant neuropeptide N-acetyl-aspartylglutamate (NAAG) into N-acetylaspartate and glutamate. NAAG has been proposed to be a neurotransmitter at a subpopulation of glutamate receptors; alternatively, NAAG has been suggested to act as a storage form of synaptic glutamate. As a result, inhibition of NAALADase may show utility as a therapeutic intervention in diseases in which altered levels of glutamate are thought to be involved. PMID:8558536

  4. MIREX INDUCES ORNITHINE DECARBOXYLASE ACTIVITY IN FEMALE RAT LIVER

    EPA Science Inventory

    Ornithine decarboxylase (ODC), the rate-limiting enzyme in polyamine synthesis, was significantly induced in female rat liver following oral administration of the pesticide, mirex. fter dual oral exposure (120 mg/kg; 21 and 4 hrs prior to sacrifice) induction of ODC activity in r...

  5. Carbonic Anhydrase Inhibitors. Part 91. Metal Complexes of Heterocyclic Sulfonamides as Potential Pharmacological Agents in the Treatment of Gastric Acid Secretion Imbalances

    PubMed Central

    Ilies, Marc A.; Scozzafava, Andrea

    2000-01-01

    Zinc, magnesium, aluminum and copper complexes of several potent, clinically used carbonic anhydrase (CA) sulfonamide inhibitors, such as acetazolamide, methazolamide, ethoxzolamide and benzolamide were tested for their possible applications as antacids, in experimental animals. Gastric acid secretion parameters 3 days after treatment with these CA inhibitors (2 × 500 mg, twice a day), in dogs with chronic gastric fistulas, led to the observation that the gastric acid parameters BAO (the basal acid output), and MAO (the maximal acid output after stimulation with histamine) were drastically reduced, as compared to the same parameters in animals that did not receive these enzyme inhibitors. These are promising results for the possible use of metal complexes of heterocyclic sulfonamides as treatment alternatives (alone or in combination with other drugs) for gastric acid secretion imbalances. PMID:18475926

  6. Immobilization by Polyurethane of Pseudomonas dacunhae Cells Containing l-Aspartate β-Decarboxylase Activity and Application to l-Alanine Production

    PubMed Central

    Fusee, Murray C.; Weber, Jennifer E.

    1984-01-01

    Whole cells of Pseudomonas dacunhae containing l-aspartate β-decarboxylase activity were immobilized by mixing a cell suspension with a liquid isocyanate-capped polyurethane prepolymer (Hypol; W. R. Grace & Co., Lexington, Mass.). The immobilized cell preparation was used to convert l-aspartic acid to l-alanine. Properties of the immobilized P. dacunhae cells containing aspartate β-decarboxylase activity were investigated with batch reactors. Retention of enzyme activity was observed to be as much as 100% when cell lysis was allowed to occur before immobilization. The pH and temperature optima were determined to be 5.5 and 45°C, respectively. Immobilized P. dacunhael-aspartate β-decarboxylase activity was stabilized by the addition of 0.1 mM pyridoxal-5-phosphate and 0.1 mM α-ketoglutaric acid to a 1.7 M ammonium aspartate (pH 5.5) substrate solution. Under conditions of semicontinuous use in a batch reactor, a 2.5% loss in immobilized l-aspartate β-decarboxylase activity was observed over a 31-day period. PMID:16346636

  7. Outcomes in patients with nonerosive reflux disease treated with a proton pump inhibitor and alginic acid ± glycyrrhetinic acid and anthocyanosides

    PubMed Central

    Di Pierro, Francesco; Gatti, Mario; Rapacioli, Giuliana; Ivaldi, Leandro

    2013-01-01

    Background The purpose of this study was to compare the efficacy of alginic acid alone versus alginic acid combined with low doses of pure glycyrrhetinic acid and bilberry anthocyanosides as an addon to conventional proton pump inhibitor therapy in relieving symptoms associated with nonerosive reflux disease. Methods This prospective, randomized, 8-week, open-label trial was conducted at two centers. Sixty-three patients with persistent symptoms of gastroesophageal reflux disease and normal upper gastrointestinal endoscopy were eligible for the study. Patients in group A (n = 31) were treated with pantoprazole and a formula (Mirgeal®) containing alginic acid and low doses of pure glycyrrhetinic acid + standardized Vaccinium myrtillus extract for 4 weeks, then crossed over to the multi-ingredient formula for a further 4 weeks. Patients in group B (n = 32) were treated pantoprazole and alginic acid alone twice daily, then crossed over to alginic acid twice daily for a further 4 weeks. Efficacy was assessed by medical evaluation of a symptom relief score, estimated using a visual analog scale (0–10). Side effects, tolerability, and compliance were also assessed. Results Of the 63 patients enrolled in the study, 58 (29 in group A and 29 in group B) completed the 8-week trial. The baseline characteristics were comparable between the two groups. During the study, significant differences were recorded in symptom scores for both groups. In group A, symptoms of chest pain, heartburn, and abdominal swelling were less serious than in group B. Treatment A was better tolerated, did not induce hypertension, and had fewer side effects than treatment B. No significant differences in compliance were found between the two groups. Conclusion Use of low doses of pure glycyrrhetinic acid + bilberry anthocyanosides, together with alginic acid as addon therapy, substantially improves symptoms in patients with nonerosive reflux disease without increasing side effects or worsening

  8. Expression, immobilization and enzymatic properties of glutamate decarboxylase fused to a cellulose-binding domain.

    PubMed

    Park, Hyemin; Ahn, Jungoh; Lee, Juwhan; Lee, Hyeokwon; Kim, Chunsuk; Jung, Joon-Ki; Lee, Hongweon; Lee, Eun Gyo

    2012-01-01

    Escherichia coli-derived glutamate decarboxylase (GAD), an enzyme that catalyzes the conversion of glutamic acid to gamma-aminobutyric acid (GABA), was fused to the cellulose-binding domain (CBD) and a linker of Trichoderma harzianum endoglucanase II. To prevent proteolysis of the fusion protein, the native linker was replaced with a S(3)N(10) peptide known to be completely resistant to E. coli endopeptidase. The CBD-GAD expressed in E. coli was successfully immobilized on Avicel, a crystalline cellulose, with binding capacity of 33 ± 2 nmol(CBD-GAD)/g(Avicel) and the immobilized enzymes retained 60% of their initial activities after 10 uses. The results of this report provide a feasible alternative to produce GABA using immobilized GAD through fusion to CBD. PMID:22312257

  9. Pyridoxal phosphate-sensitized photoinactivation of glutamate decarboxylase from Clostridium perfringens

    PubMed Central

    Cozzani, Ivo; Santoni, Costantino; Jori, Giulio; Gennari, Giorgio; Tamburro, Antonio Mario

    1974-01-01

    1. l-Glutamate decarboxylase (EC 4.1.1.15) from Clostridium perfringens was inactivated by exposure to visible light at pH6.2. 2. Inactivation does not occur at pH4.6 or in the absence of bound pyridoxal phosphate. 3. On prolonged photo-oxidation six histidine residues per molecule of enzyme were destroyed. 4. The loss of six cysteine residues per molecule occurred both in irradiated samples and in controls oxygenated in the dark. 5. This dark-oxidation of cysteine residues is apparently required before the photo-oxidation process. 6. The absorbance, fluorescence and circular-dichroism properties of the enzyme as well as its elution volume during Sephadex gel-filtration were unaffected by prolonged irradiation. 7. However, an apparently homogeneous product of photo-oxidation could be separated from the control enzyme by ion-exchange chromatography. 8. The Km for l-glutamate was unchanged in an irradiated sample retaining 22% of control activity. 9. These data and the catalytic role of imidazole residues at the active sites of amino acid decarboxylases are discussed. PMID:4375980

  10. A Second 5-Carboxyvanillate Decarboxylase Gene, ligW2, Is Important for Lignin-Related Biphenyl Catabolism in Sphingomonas paucimobilis SYK-6

    PubMed Central

    Peng, Xue; Masai, Eiji; Kasai, Daisuke; Miyauchi, Keisuke; Katayama, Yoshihiro; Fukuda, Masao

    2005-01-01

    A lignin-related biphenyl compound, 5,5′-dehydrodivanillate (DDVA), is degraded to 5-carboxyvanillate (5CVA) by the enzyme reactions catalyzed by DDVA O-demethylase (LigX), meta-cleavage oxygenase (LigZ), and meta-cleavage compound hydrolase (LigY) in Sphingomonas paucimobilis SYK-6. 5CVA is then transformed to vanillate by a nonoxidative 5CVA decarboxylase and is further degraded through the protocatechuate 4,5-cleavage pathway. A 5CVA decarboxylase gene, ligW, was isolated from SYK-6 (X. Peng, E. Masai, H. Kitayama, K. Harada, Y, Katayama, and M. Fukuda, Appl. Environ. Microbiol. 68:4407-4415, 2002). However, disruption of ligW slightly affected the 5CVA decarboxylase activity and the growth rate on DDVA of the mutant, suggesting the presence of an alternative 5CVA decarboxylase gene. Here we isolated a second 5CVA decarboxylase gene, ligW2, which consists of a 1,050-bp open reading frame encoding a polypeptide with a molecular mass of 39,379 Da. The deduced amino acid sequence encoded by ligW2 exhibits 37% identity with the sequence encoded by ligW. Based on a gas chromatography-mass spectrometry analysis of the reaction product from 5CVA catalyzed by LigW2 in the presence of deuterium oxide, LigW2 was indicated to be a nonoxidative decarboxylase of 5CVA, like LigW. After disruption of ligW2, both the growth rate on DDVA and the 5CVA decarboxylase activity of the mutant were decreased to approximately 30% of the wild-type levels. The ligW ligW2 double mutant lost both the ability to grow on DDVA and the 5CVA decarboxylase activity. These results indicate that both ligW and ligW2 contribute to 5CVA degradation, although ligW2 plays the more important role in the growth of SYK-6 cells on DDVA. PMID:16151081

  11. Biphenyl-4-yl-acrylohydroxamic acids: Identification of a novel indolyl-substituted HDAC inhibitor with antitumor activity.

    PubMed

    Cincinelli, Raffaella; Zwick, Vincent; Musso, Loana; Zuco, Valentina; De Cesare, Michelandrea; Zunino, Franco; Simoes-Pires, Claudia; Nurisso, Alessandra; Giannini, Giuseppe; Cuendet, Muriel; Dallavalle, Sabrina

    2016-04-13

    Modification of the cap group of biphenylacrylohydroxamic acid-based HDAC inhibitors led to the identification of a new derivative (3) characterized by an indolyl-substituted 4-phenylcinnamic skeleton. Molecular docking was used to predict the optimal conformation in the class I HDACs active site. Compound 3 showed HDAC inhibitory activity and antiproliferative activity against a panel of tumor cell lines, in the low μM range. The compound was further tested in vitro for acetylation of histone H4 and other non-histone proteins, and in vivo in a colon carcinoma model, showing significant proapoptotic and antitumor activities. PMID:26890116

  12. CE-LIF determination of salivary cadaverine and lysine concentration ratio as an indicator of lysine decarboxylase enzyme activity.

    PubMed

    Tábi, Tamás; Lohinai, Zsolt; Pálfi, Melinda; Levine, Martin; Szöko, Eva

    2008-05-01

    Salivary bacteria produce the enzyme lysine decarboxylase which converts lysine to cadaverine. In the absence of appropriate oral hygiene, overgrowth of these bacteria depletes lysine. This may contribute to gingival inflammation, while cadaverine contributes to oral malodor. A selective and sensitive capillary electrophoresis method with laser-induced fluorescence detection has been developed for the determination of cadaverine and lysine in saliva, as an indicator of lysine decarboxylase enzyme activity. The diamino compounds were separated in acidic background electrolyte in their mono-labeled form after derivatization with 4-fluoro-7-nitrobenz-2-oxa-1,3-diazole (NBD-F). Linearity and reproducibility of the method in the range 1-50 μmol L(-1) have been demonstrated using saliva samples. The method was applied for the measurement of cadaverine and lysine in the saliva of healthy volunteers with or without proper oral hygiene. In the absence of oral hygiene, the mol fraction of cadaverine to cadaverine plus lysine in saliva increased significantly (0.65 ± 0.13 vs. 0.39 ± 0.18, P < 0.001), indicating the presence of higher amount of bacterial lysine decarboxylase, that may contribute to periodontal diseases. PMID:18389226

  13. Sbi00515, a Protein of Unknown Function from Streptomyces bingchenggensis, Highlights the Functional Versatility of the Acetoacetate Decarboxylase Scaffold.

    PubMed

    Mueller, Lisa S; Hoppe, Robert W; Ochsenwald, Jenna M; Berndt, Robert T; Severin, Geoffrey B; Schwabacher, Alan W; Silvaggi, Nicholas R

    2015-06-30

    The acetoacetate decarboxylase-like superfamily (ADCSF) is a group of ~4000 enzymes that, until recently, was thought to be homogeneous in terms of the reaction catalyzed. Bioinformatic analysis shows that the ADCSF consists of up to seven families that differ primarily in their active site architectures. The soil-dwelling bacterium Streptomyces bingchenggensis BCW-1 produces an ADCSF enzyme of unknown function that shares a low level of sequence identity (~20%) with known acetoacetate decarboxylases (ADCs). This enzyme, Sbi00515, belongs to the MppR-like family of the ADCSF because of its similarity to the mannopeptimycin biosynthetic protein MppR from Streptomyces hygroscopicus. Herein, we present steady state kinetic data that show Sbi00515 does not catalyze the decarboxylation of any α- or β-keto acid tested. Rather, we show that Sbi00515 catalyzes the condensation of pyruvate with a number of aldehydes, followed by dehydration of the presumed aldol intermediate. Thus, Sbi00515 is a pyruvate aldolase-dehydratase and not an acetoacetate decarboxylase. We have also determined the X-ray crystal structures of Sbi00515 in complexes with formate and pyruvate. The structures show that the overall fold of Sbi00515 is nearly identical to those of both ADC and MppR. The pyruvate complex is trapped as the Schiff base, providing evidence that the Schiff base chemistry that drives the acetoacetate decarboxylases has been co-opted to perform a new function, and that this core chemistry may be conserved across the superfamily. The structures also suggest possible catalytic roles for several active site residues. PMID:26039798

  14. Bacterial Lysine Decarboxylase Influences Human Dental Biofilm Lysine Content, Biofilm Accumulation and Sub-Clinical Gingival Inflammation

    PubMed Central

    Lohinai, Z.; Keremi, B.; Szoko, E.; Tabi, T.; Szabo, C.; Tulassay, Z.; Levine, M.

    2012-01-01

    Background Dental biofilms contain a protein that inhibits mammalian cell growth, possibly lysine decarboxylase from Eikenella corrodens. This enzyme decarboxylates lysine, an essential amino acid for dentally attached cell turnover in gingival sulci. Lysine depletion may stop this turnover, impairing the barrier to bacterial compounds. The aims of this study were to determine biofilm lysine and cadaverine contents before oral hygiene restriction (OHR), and their association with plaque index (PI) and gingival crevicular fluid (GCF) after OHR for a week. Methods Laser-induced fluorescence after capillary electrophoresis was used to determine lysine and cadaverine contents in dental biofilm, tongue biofilm and saliva before OHR and in dental biofilm after OHR. Results Before OHR, lysine and cadaverine contents of dental biofilm were similar and 10-fold greater than in saliva or tongue biofilm. After a week of OHR, the biofilm content of cadaverine increased and that of lysine decreased, consistent with greater biofilm lysine decarboxylase activity. Regression indicated that PI and GCF exudation were positively related to biofilm lysine post-OHR, unless biofilm lysine exceeded the minimal blood plasma content in which case PI was further increased but GCF exudation was reduced. Conclusions After OHR, lysine decarboxylase activity seems to determine biofilm lysine content and biofilm accumulation. When biofilm lysine exceeds minimal blood plasma content after OHR, less GCF appeared despite more biofilm. Lysine appears important for biofilm accumulation and the epithelial barrier to bacterial proinflammatory agents. Clinical Relevance Inhibiting lysine decarboxylase may retard the increased GCF exudation required for microbial development and gingivitis. PMID:22141361

  15. Cyclopiazonic acid, an inhibitor of calcium-dependent ATPases with antiviral activity against human respiratory syncytial virus.

    PubMed

    Cui, Rui; Wang, Yizhuo; Wang, Liu; Li, Guiming; Lan, Ke; Altmeyer, Ralf; Zou, Gang

    2016-08-01

    Human respiratory syncytial virus (RSV) is a common cause of lower respiratory tract infections in infants and young children worldwide, yet no vaccine or effective antiviral treatment is available. To search for new anti-RSV agents, we developed a cell-based assay that measures inhibition of RSV-induced cytopathic effect (CPE) and identified cyclopiazonic acid (CPA), an intracellular calcium ATPase inhibitor as a RSV inhibitor (EC50 values 4.13 μM) by screening of natural product library. CPA inhibited the replication of RSV strains belonging to both A and B subgroups and human parainfluenza virus type 3, but not Enterovirus 71. Mechanism of action study by time-of-addition assay and minigenome assay revealed that CPA acts at the step of virus genome replication and/or transcription. Moreover, two other calcium ATPase inhibitors (Thapsigargin and BHQ) and calcium ionophores (A23187 and ionomycin), but not calcium channel blockers (nifedipine, nimodipine, and tetrandrine), also had similar effect. These results indicate that an increase in intracellular calcium concentration is detrimental to RSV replication. Thus, our findings provide a new strategy for anti-RSV therapy via increasing intracellular calcium concentration. PMID:27210812

  16. Bioactivity Focus of α-Cyano-4-hydroxycinnamic acid (CHCA) Leads to Effective Multifunctional Aldose Reductase Inhibitors.

    PubMed

    Zhang, Laitao; Li, Yi-Fang; Yuan, Sheng; Zhang, Shijie; Zheng, Huanhuan; Liu, Jie; Sun, Pinghua; Gu, Yijun; Kurihara, Hiroshi; He, Rong-Rong; Chen, Heru

    2016-01-01

    Bioactivity focus on α-cyano-4-hydroxycinnamic acid (CHCA) scaffold results in a small library of novel multifunctional aldose reductase (ALR2) inhibitors. All the entities displayed good to excellent inhibition with IC50 72-405 nM. (R,E)-N-(3-(2-acetamido-3-(benzyloxy)propanamido)propyl)-2-cyano-3-(4-hydroxy phenyl)acrylamide (5f) was confirmed as the most active inhibitor (IC50 72.7 ± 1.6 nM), and the best antioxidant. 5f bound to ALR2 with new mode without affecting the aldehyde reductase (ALR1) activity, implicating high selectivity to ALR2. 5f was demonstrated as both an effective ALR2 inhibitor (ARI) and antioxidant in a chick embryo model of hyperglycemia. It attenuated hyperglycemia-induced incidence of neural tube defects (NTD) and death rate, and significantly improved the body weight and morphology of the embryos. 5f restored the expression of paired box type 3 transcription factor (Pax3), and reduced the hyperglycemia-induced increase of ALR2 activity, sorbitol accumulation, and the generation of ROS and MDA to normal levels. All the evidences support that 5f may be a potential agent to treat diabetic complications. PMID:27109517

  17. Structure-activity relationships of anthraquinone derivatives derived from bromaminic acid as inhibitors of ectonucleoside triphosphate diphosphohydrolases (E-NTPDases)

    PubMed Central

    Baqi, Younis; Weyler, Stefanie; Iqbal, Jamshed; Zimmermann, Herbert

    2008-01-01

    Reactive blue 2 (RB-2) had been characterized as a relatively potent ectonucleoside triphosphate diphosphohydrolase (E-NTPDase) inhibitor with some selectivity for NTPDase3. In search for the pharmacophore and to analyze structure-activity relationships we synthesized a series of truncated derivatives and analogs of RB-2, including 1-amino-2-sulfo-4-ar(alk)ylaminoanthraquinones, 1-amino-2-methyl-4-arylaminoanthraquinones, 1-amino-4-bromoanthraquinone 2-sulfonic acid esters and sulfonamides, and bis-(1-amino-4-bromoanthraquinone) sulfonamides, and investigated them in preparations of rat NTPDase1, 2, and 3 using a capillary electrophoresis assay. Several 1-amino-2-sulfo-4-ar(alk)ylaminoanthraquinone derivatives inhibited E-NTPDases in a concentration-dependent manner. The 2-sulfonate group was found to be required for inhibitory activity, since 2-methyl-substituted derivatives were inactive. 1-Amino-2-sulfo-4-p-chloroanilinoanthraquinone (18) was identified as a nonselective competitive blocker of NTPDases1, 2, and 3 (Ki 16–18 μM), while 1-amino-2-sulfo-4-(2-naphthylamino)anthraquinone (21) was a potent inhibitor with preference for NTPDase1 (Ki 0.328 μM) and NTPDase3 (Ki 2.22 μM). Its isomer, 1-amino-2-sulfo-4-(1-naphthylamino)anthraquinone (20), was a potent and selective inhibitor of rat NTPDase3 (Ki 1.5 μM). PMID:18528783

  18. Renoprotective effect of DPP-4 inhibitors against free fatty acid-bound albumin-induced renal proximal tubular cell injury.

    PubMed

    Tanaka, Yuki; Kume, Shinji; Chin-Kanasaki, Masami; Araki, Hisazumi; Araki, Shin-ichi; Ugi, Satoshi; Sugaya, Takeshi; Uzu, Takashi; Maegawa, Hiroshi

    2016-02-12

    Dipeptidyl peptidase (DPP)-4 inhibitors, a new class of antidiabetic agent, have recently been suggested to exert pleiotropic effects beyond glucose lowering. Renal prognosis in patients with diabetic nephropathy depends on the severity of tubulointerstitial injury induced by massive proteinuria. We thus examined the renoprotective effect of DPP-4 inhibitors on inflammation in cultured mouse proximal tubular cells stimulated with free fatty acid (FFA)-bound albumin. Linagliptin and higher concentrations of sitagliptin, vildagliptin, and alogliptin all inhibited FFA-bound albumin-induced increases in mRNA expression of MCP-1 in cultured mouse proximal tubular cells. Furthermore, linagliptin significantly inhibited tubulointerstitial injury induced by peritoneal injection of FFA-bound albumin, such as inflammation, fibrosis, and apoptosis, in mice without altering systemic characteristics including body weight, fasting blood glucose, and food intake. These results indicate that DPP-4 inhibitors pleiotropically exert a direct renoprotective effect, and may serve as an additional therapeutic strategy to protect proximal tubular cells against proteinuria in patients with diabetic nephropathy. PMID:26802469

  19. Bioactivity Focus of α-Cyano-4-hydroxycinnamic acid (CHCA) Leads to Effective Multifunctional Aldose Reductase Inhibitors

    PubMed Central

    Zhang, Laitao; Li, Yi-Fang; Yuan, Sheng; Zhang, Shijie; Zheng, Huanhuan; Liu, Jie; Sun, Pinghua; Gu, Yijun; Kurihara, Hiroshi; He, Rong-Rong; Chen, Heru

    2016-01-01

    Bioactivity focus on α-cyano-4-hydroxycinnamic acid (CHCA) scaffold results in a small library of novel multifunctional aldose reductase (ALR2) inhibitors. All the entities displayed good to excellent inhibition with IC50 72–405 nM. (R,E)-N-(3-(2-acetamido-3-(benzyloxy)propanamido)propyl)-2-cyano-3-(4-hydroxy phenyl)acrylamide (5f) was confirmed as the most active inhibitor (IC50 72.7 ± 1.6 nM), and the best antioxidant. 5f bound to ALR2 with new mode without affecting the aldehyde reductase (ALR1) activity, implicating high selectivity to ALR2. 5f was demonstrated as both an effective ALR2 inhibitor (ARI) and antioxidant in a chick embryo model of hyperglycemia. It attenuated hyperglycemia-induced incidence of neural tube defects (NTD) and death rate, and significantly improved the body weight and morphology of the embryos. 5f restored the expression of paired box type 3 transcription factor (Pax3), and reduced the hyperglycemia-induced increase of ALR2 activity, sorbitol accumulation, and the generation of ROS and MDA to normal levels. All the evidences support that 5f may be a potential agent to treat diabetic complications. PMID:27109517

  20. Potent and Selective α-Ketoheterocycle-Based Inhibitors of the Anandamide and Oleamide Catabolizing Enzyme, Fatty Acid Amide Hydrolase

    PubMed Central

    Romero, F. Anthony; Du, Wu; Hwang, Inkyu; Rayl, Thomas J.; Kimball, F. Scott; Leung, Donmienne; Hoover, Heather S.; Apodaca, Richard L.; Breitenbucher, J. Guy; Cravatt, Benjamin F.; Boger, Dale L.

    2008-01-01

    A study of the structure–activity relationships (SAR) of 2f (OL-135), a potent inhibitor of fatty acid amide hydrolase (FAAH), is detailed targeting the 5-position of the oxazole. Examination of a series of substituted benzene derivatives (12–14) revealed that the optimal position for substitution was the meta-position with selected members approaching or exceeding the potency of 2f. Concurrent with these studies, the effect of substitution on the pyridine ring of 2f was also examined. A series of small, non-aromatic C5-substituents was also explored and revealed that the Ki follows a well-defined correlation with the Hammett σp constant (ρ = 3.01, R2 = 0.91) in which electron-withdrawing substituents enhance potency leading to inhibitors with Ki’s as low as 400 pM (20n). Proteomic-wide screening of the inhibitors revealed that most are exquisitely selective for FAAH over all other mammalian proteases reversing the 100-fold preference of 20a (C5 substituent = H) for the enzyme TGH. PMID:17279740

  1. The macamide N-3-methoxybenzyl-linoleamide is a time-dependent fatty acid amide hydrolase (FAAH) inhibitor.

    PubMed

    Almukadi, Haifa; Wu, Hui; Böhlke, Mark; Kelley, Charles J; Maher, Timothy J; Pino-Figueroa, Alejandro

    2013-10-01

    The Peruvian plant Lepidium meyenii (Maca) has been shown to possess neuroprotective activity both in vitro and in vivo. Previous studies have also demonstrated the activity of the pentane extract and its macamides, the most representative lipophilic constituents of Maca, in the endocannabinoid system as fatty acid amide hydrolase (FAAH) inhibitors. One of the most active macamides, N-3-methoxybenzyl-linoleamide, was studied to determine its mechanism of interaction with FAAH and whether it has inhibitory activity on mono-acyl glycerol lipase (MAGL), the second enzyme responsible for endocannabinoid degradation. Macamide concentrations from 1 to 100 μM were tested using FAAH and MAGL inhibitor assay methods and showed no effect on MAGL. Tests with other conditions were performed in order to characterize the inhibitory mechanism of FAAH inhibition. N-3-methoxybenzyl-linoleamide displayed significant time-dependent and dose-dependent FAAH inhibitory activity. The mechanism of inhibition was most likely irreversible or slowly reversible. These results suggest the potential application of macamides isolated from Maca as FAAH inhibitors, as they might act on the central nervous system to provide analgesic, anti-inflammatory, or neuroprotective effects, by modulating the release of neurotransmitters. PMID:23853040

  2. Design, synthesis and evaluation of semi-synthetic triazole-containing caffeic acid analogues as 5-lipoxygenase inhibitors.

    PubMed

    De Lucia, Daniela; Lucio, Oscar Méndez; Musio, Biagia; Bender, Andreas; Listing, Monika; Dennhardt, Sophie; Koeberle, Andreas; Garscha, Ulrike; Rizzo, Roberta; Manfredini, Stefano; Werz, Oliver; Ley, Steven V

    2015-08-28

    In this work the synthesis, structure-activity relationship (SAR) and biological evaluation of a novel series of triazole-containing 5-lipoxygenase (5-LO) inhibitors are described. The use of structure-guided drug design techniques provided compounds that demonstrated excellent 5-LO inhibition with IC50 of 0.2 and 3.2 μm in cell-based and cell-free assays, respectively. Optimization of binding and functional potencies resulted in the identification of compound 13d, which showed an enhanced activity compared to the parent bioactive compound caffeic acid 5 and the clinically approved zileuton 3. Compounds 15 and 16 were identified as lead compounds in inhibiting 5-LO products formation in neutrophils. Their interference with other targets on the arachidonic acid pathway was also assessed. Cytotoxicity tests were performed to exclude a relationship between cytotoxicity and the increased activity observed after structure optimization. PMID:26197161

  3. The pharmacology and therapeutic potential of small molecule inhibitors of acid-sensing ion channels in stroke intervention

    PubMed Central

    Leng, Tian-dong; Xiong, Zhi-gang

    2013-01-01

    In the nervous system, a decrease in extracellular pH is a common feature of various physiological and pathological processes, including synaptic transmission, cerebral ischemia, epilepsy, brain trauma, and tissue inflammation. Acid-sensing ion channels (ASICs) are proton-gated cation channels that are distributed throughout the central and peripheral nervous systems. Following the recent identification of ASICs as critical acid-sensing extracellular proton receptors, growing evidence has suggested that the activation of ASICs plays important roles in physiological processes such as nociception, mechanosensation, synaptic plasticity, learning and memory. However, the over-activation of ASICs is also linked to adverse outcomes for certain pathological processes, such as brain ischemia and multiple sclerosis. Based on the well-demonstrated role of ASIC1a activation in acidosis-mediated brain injury, small molecule inhibitors of ASIC1a may represent novel therapeutic agents for the treatment of neurological disorders, such as stroke. PMID:22820909

  4. A Potent Systemically Active N-Acylethanolamine Acid Amidase Inhibitor that Suppresses Inflammation and Human Macrophage Activation.

    PubMed

    Ribeiro, Alison; Pontis, Silvia; Mengatto, Luisa; Armirotti, Andrea; Chiurchiù, Valerio; Capurro, Valeria; Fiasella, Annalisa; Nuzzi, Andrea; Romeo, Elisa; Moreno-Sanz, Guillermo; Maccarrone, Mauro; Reggiani, Angelo; Tarzia, Giorgio; Mor, Marco; Bertozzi, Fabio; Bandiera, Tiziano; Piomelli, Daniele

    2015-08-21

    Fatty acid ethanolamides such as palmitoylethanolamide (PEA) and oleoylethanolamide (OEA) are lipid-derived mediators that potently inhibit pain and inflammation by ligating type-α peroxisome proliferator-activated receptors (PPAR-α). These bioactive substances are preferentially degraded by the cysteine hydrolase, N-acylethanolamine acid amidase (NAAA), which is highly expressed in macrophages. Here, we describe a new class of β-lactam derivatives that are potent, selective, and systemically active inhibitors of intracellular NAAA activity. The prototype of this class deactivates NAAA by covalently binding the enzyme's catalytic cysteine and exerts profound anti-inflammatory effects in both mouse models and human macrophages. This agent may be used to probe the functions of NAAA in health and disease and as a starting point to discover better anti-inflammatory drugs. PMID:25874594

  5. Design, synthesis and SAR studies of GABA uptake inhibitors derived from 2-substituted pyrrolidine-2-yl-acetic acids.

    PubMed

    Steffan, Tobias; Renukappa-Gutke, Thejavathi; Höfner, Georg; Wanner, Klaus T

    2015-03-15

    In this paper, we disclose the design and synthesis of a series of 2-substituted pyrrolidine-2-yl-acetic acid as core structures and the N-arylalkyl derivatives thereof as potential GABA transport inhibitors. The 2-position in the side chain of pyrrolidine-2-yl-acetic acid derivatives was substituted with alkyl, hydroxy and amino groups to modulate the activity and selectivity to mGAT1 and mGAT4 proteins. SAR studies of the compounds performed for the four mouse GABA transporter proteins (mGAT1-mGAT4) implied significant potencies and subtype selectivities for 2-hydroxy-2-pyrrolidine-2-yl-acetic acid derivatives. The racemate rac-(u)-13c exhibited the highest potency (pIC50 5.67) at and selectivity for mGAT1 in GABA uptake assays. In fact, the potency of rac-(u)-13c at hGAT-1 (pIC50 6.14) was even higher than its potency at mGAT1. These uptake results for rac-(u)-13c are in line with the binding affinities to the aforesaid proteins mGAT1 (pKi 6.99) and hGAT-1 (pKi 7.18) determined by MS Binding Assay based on NO711 as marker quantified by LC-ESI-MS-MS analysis. Interestingly, the 2-hydroxy-2-pyrrolidine-2-yl-acetic acid rac-(u)-13d containing 2-{[tris(4-methoxyphenyl)]methoxy} ethyl group at the nitrogen atom of the pyrrolidine ring showed high potency at mGAT4 and a comparatively better selectivity for this protein (>15 against mGAT3) than the well known mGAT4 uptake inhibitor (S)-SNAP-5114. PMID:25698617

  6. Synthesis and bioevaluation of 2-phenyl-4-methyl-1,3-selenazole-5-carboxylic acids as potent xanthine oxidase inhibitors.

    PubMed

    Guan, Qi; Cheng, Zengjin; Ma, Xiaoxue; Wang, Lijie; Feng, Dongjie; Cui, Yuanhang; Bao, Kai; Wu, Lan; Zhang, Weige

    2014-10-01

    A series of 2-phenyl-4-methyl-1,3-selenazole-5-carboxylic acid derivatives (8a-f, 9a-m) were synthesized and evaluated for inhibitory activity against xanthine oxidase in vitro. Structure-activity relationship analyses have also been presented. Most of the target compounds exhibited potency levels in the nanomolar range. Compound 9e emerged as the most potent xanthine oxidase inhibitor (IC50 = 5.5 nM) in comparison to febuxostat (IC50 = 18.6 nM). Steady-state kinetics measurements with the bovine milk enzyme indicated a mixed type inhibition with Ki and Ki' values of 0.9 and 2.3 nM, respectively. A molecular modeling study on compounds 9e was performed to gain an insight into its binding mode with xanthine oxidase, and to provide the basis for further structure-guided design of new non-purine xanthine oxidase inhibitors related with 2-phenyl-4-methyl-1,3-selenazole-5-carboxylic acid scaffold. PMID:25113879

  7. Expression in Pichia pastoris and characterization of APETx2, a specific inhibitor of acid sensing ion channel 3.

    PubMed

    Anangi, Raveendra; Chen, Chih-Cheng; Lin, Yi-Wen; Cheng, Yuan-Ren; Cheng, Chun-Ho; Chen, Yi-Chun; Chu, Yuan-Ping; Chuang, Woei-Jer

    2010-12-01

    Acid sensing ion channels (ASICs) are family of proteins predominantly present in the central and peripheral nervous system. They are known to play important roles in the pathophysiology of pain and ischemic stroke. APETx2 is a potent and selective inhibitor of ASIC3-containing channels and was isolated from sea anemone Anthopleura elegantissima. To facilitate the study on the molecular determinants of ASIC3-ligand interactions, we expressed recombinant APETx2 in the Pichia pastoris (P. pastoris) expression system and purified it to homogeneity. Recombinant APETx2 produced in P. pastoris inhibited the acid-evoked ASIC3 current with the IC(50) value of 37.3 nM. The potency of recombinant toxin is similar to that of native APETx2. The sequential assignment and structure analysis of APETx2 were obtained by 2D and 3D (15)N-edited NMR spectra. Our NMR data suggests that APETx2 produced in P. pastoris retained its native fold. The results presented here provide the first direct evidence that highly disulfide bonded peptide inhibitor of ASIC3, APETx2, can be expressed in P. pastoris with correct fold and high yield. We also showed that the R17A mutant exhibited a decrease in activity, suggesting the feasibility of the use of this expression system to study the interactions between APETx2 and ASIC3. These evidences may serve as the basis for understanding the selectivity and activity of APETx2. PMID:20813121

  8. Effects of COX inhibitors on neurodegeneration and survival in mice exposed to the marine neurotoxin domoic acid.

    PubMed

    Ryan, James C; Cross, Cheryl A; Van Dolah, Frances M

    2011-01-01

    The marine neurotoxin domoic acid (DA) is a rigid analogue of the neurotransmitter glutamate and a potent agonist of kainate subtype glutamate receptors. Persistent activation of these receptor subtypes results in rapid excitotoxicity, calcium-dependent cell death, and neuronal degeneration in regions of the brain where glutamatergic pathways are concentrated. Previous work has shown that DA promotes the expression of inflammatory genes in the brain, such as cyclooxygenase 2 (COX2). To investigate the impact of inflammation on the development of neurodegeneration, and ultimately survival following DA administration, we used selective (L745337, Merck) and non-selective (acetylsalicylic acid (ASA)) COX inhibitors in DA exposed mice. Adult male ICR mice were given a regime of either ASA or L23547 both before and after a single LD50 dose of DA. Mice were observed immediately after toxin introduction and then sacrificed at 2 days post exposure. Our lower dose of L23547 increased survival and was most effective at decreasing neuronal degeneration in the CA1 and CA3 regions of the hippocampus, areas especially sensitive to DA excitotoxicity. This study shows that COX2 plays a role in DA induced neurodegeneration and death, and that inhibitors may be of value for treatment in human and wildlife DA exposure. PMID:20934488

  9. Development of Highly Potent GAT1 Inhibitors: Synthesis of Nipecotic Acid Derivatives by Suzuki-Miyaura Cross-Coupling Reactions.

    PubMed

    Petrera, Marilena; Wein, Thomas; Allmendinger, Lars; Sindelar, Miriam; Pabel, Jörg; Höfner, Georg; Wanner, Klaus T

    2016-03-01

    A new series of potent and selective mGAT1 inhibitors has been identified, featuring a nipecotic acid residue and an N-butenyl linker with a 2-biphenyl residue at the ω-position. Docking, combined with MD calculations, revealed a binding mode for the new compounds similar to that of tiagabine, the only mGAT1 inhibitor currently approved as antiepileptic drug. For the synthesis, a Suzuki-Miyaura cross-coupling reaction was used as a key step by which variously substituted biaryl subunits were assembled. Biological evaluation revealed several compounds that possess binding affinities and inhibitory potencies toward mGAT1, together with subtype selectivities against mGAT2-mGAT4 that were similar to or even higher than those for tiagabine. A derivative carrying the 2',4'-dichloro-2-biphenyl moiety attached to N-but-3-enylnipecotic acid at the terminal position of the linker chain was found to be the most potent binder, with the racemic form of the compound displaying a binding affinity of 8.05±0.13 (pKi ), while the R enantiomer exhibited an affinity value of 8.33±0.06 (pKi ). PMID:26683881

  10. Complexes of Imidazole with Poly(ethylene glycol) as a Corrosion Inhibitor for Carbon Steel in Sulphuric Acid

    NASA Astrophysics Data System (ADS)

    Salimi, Saeed; Nasr-Esfahani, Mojtaba; Umoren, Saviour A.; Saebnoori, Ehsan

    2015-12-01

    The inhibiting action of polyethylene glycol and imidazole (PEG/IMZ)) complexes prepared by a simple deprotonation procedure on carbon steel corrosion in 0.5 mol/L sulphuric acid was evaluated using the weight loss, potentiodynamic polarization, and electrochemical impedance spectroscopy techniques complemented by surface analysis using scanning electron microscopy. The inhibiting effect of the PEG/IMZ complexes on carbon steel corrosion was compared with the non-complex forms. Results obtained show that PEG/IMZ complex is a very effective corrosion inhibitor of carbon steel in the acid environment. The inhibition efficiency increased with the increase in the temperature and also with increasing percentage of imidazole in the complex. Corrosion inhibition occurs by virtue of adsorption of PEG/IMZ complexes on the steel surface which was found to follow the Temkin adsorption isotherm model. The PEG/IMZ complexes function as a mixed-type inhibitor. Results from all the methods employed are in a reasonably good agreement.

  11. Influence of precursors and inhibitor on the production of extracellular 5-aminolevulinic acid and biomass by Rhodopseudomonas palustris KG31.

    PubMed

    Saikeur, Angkana; Choorit, Wanna; Prasertsan, Poonsuk; Kantachote, Duangporn; Sasaki, Ken

    2009-05-01

    5-Aminolevulinic acid (ALA) and the biomass of photosynthetic bacteria, Rhodopseudomonas palustris KG31, have very high potential for development and exploitation as bioherbicide and biofertilizer respectively. In this work, the effects of two precursors and an inhibitor of aminolevulinic dehydratase (ALAD) added to the VFA culture medium on the production of ALA and biomass were investigated. The experimental runs were carried out according to a Box-Behnken design. The precursors were added to the medium at the beginning of cultivation, while the inhibitor was added after 24 h. Statistical analysis indicated that levulinic acid (LA) has a positive effect on ALA production while glycine has a negative effect on biomass production. In order to enhance both ALA and biomass products, the most suitable medium was VFA medium supplemented with 3.0 mM glycine and 10 mM LA, giving ALA and biomass of 182.91 microM and 3.1 gDCW/l within 54 h. PMID:19420716

  12. Biophysical Investigation of the Mode of Inhibition of Tetramic Acids, the Allosteric Inhibitors of Undecaprenyl Pyrophosphate Synthase

    PubMed Central

    2010-01-01

    Undecaprenyl pyrophosphate synthase (UPPS) catalyzes the consecutive condensation of eight molecules of isopentenyl pyrophosphate (IPP) with farnesyl pyrophosphate (FPP) to generate the C55 undecaprenyl pyrophosphate (UPP). It has been demonstrated that tetramic acids (TAs) are selective and potent inhibitors of UPPS, but the mode of inhibition was unclear. In this work, we used a fluorescent FPP probe to study possible TA binding at the FPP binding site. A photosensitive TA analogue was designed and synthesized for the study of the site of interaction of TA with UPPS using photo-cross-linking and mass spectrometry. The interaction of substrates with UPPS and with the UPPS·TA complex was investigated by protein fluorescence spectroscopy. Our results suggested that tetramic acid binds to UPPS at an allosteric site adjacent to the FPP binding site. TA binds to free UPPS enzyme but not to substrate-bound UPPS. Unlike Escherichia coli UPPS which follows an ordered substrate binding mechanism, Streptococcus pneumoniae UPPS appears to follow a random-sequential substrate binding mechanism. Only one substrate, FPP or IPP, is able to bind to the UPPS·TA complex, but the quaternary complex, UPPS·TA·FPP·IPP, cannot be formed. We propose that binding of TA to UPPS significantly alters the conformation of UPPS needed for proper substrate binding. As the result, substrate turnover is prevented, leading to the inhibition of UPPS catalytic activity. These probe compounds and biophysical assays also allowed us to quickly study the mode of inhibition of other UPPS inhibitors identified from a high-throughput screening and inhibitors produced from a medicinal chemistry program. PMID:20476728

  13. Biophysical investigation of the mode of inhibition of tetramic acids, the allosteric inhibitors of undecaprenyl pyrophosphate synthase.

    PubMed

    Lee, Lac V; Granda, Brian; Dean, Karl; Tao, Jianshi; Liu, Eugene; Zhang, Rui; Peukert, Stefan; Wattanasin, Sompong; Xie, Xiaoling; Ryder, Neil S; Tommasi, Ruben; Deng, Gejing

    2010-06-29

    Undecaprenyl pyrophosphate synthase (UPPS) catalyzes the consecutive condensation of eight molecules of isopentenyl pyrophosphate (IPP) with farnesyl pyrophosphate (FPP) to generate the C(55) undecaprenyl pyrophosphate (UPP). It has been demonstrated that tetramic acids (TAs) are selective and potent inhibitors of UPPS, but the mode of inhibition was unclear. In this work, we used a fluorescent FPP probe to study possible TA binding at the FPP binding site. A photosensitive TA analogue was designed and synthesized for the study of the site of interaction of TA with UPPS using photo-cross-linking and mass spectrometry. The interaction of substrates with UPPS and with the UPPS.TA complex was investigated by protein fluorescence spectroscopy. Our results suggested that tetramic acid binds to UPPS at an allosteric site adjacent to the FPP binding site. TA binds to free UPPS enzyme but not to substrate-bound UPPS. Unlike Escherichia coli UPPS which follows an ordered substrate binding mechanism, Streptococcus pneumoniae UPPS appears to follow a random-sequential substrate binding mechanism. Only one substrate, FPP or IPP, is able to bind to the UPPS.TA complex, but the quaternary complex, UPPS.TA.FPP.IPP, cannot be formed. We propose that binding of TA to UPPS significantly alters the conformation of UPPS needed for proper substrate binding. As the result, substrate turnover is prevented, leading to the inhibition of UPPS catalytic activity. These probe compounds and biophysical assays also allowed us to quickly study the mode of inhibition of other UPPS inhibitors identified from a high-throughput screening and inhibitors produced from a medicinal chemistry program. PMID:20476728

  14. Effects of Fatty Acid Amide Hydrolase (FAAH) Inhibitors in Non-Human Primate Models of Nicotine Reward and Relapse.

    PubMed

    Justinova, Zuzana; Panlilio, Leigh V; Moreno-Sanz, Guillermo; Redhi, Godfrey H; Auber, Alessia; Secci, Maria E; Mascia, Paola; Bandiera, Tiziano; Armirotti, Andrea; Bertorelli, Rosalia; Chefer, Svetlana I; Barnes, Chanel; Yasar, Sevil; Piomelli, Daniele; Goldberg, Steven R

    2015-08-01

    Inhibition of the enzyme fatty acid amide hydrolase (FAAH) counteracts reward-related effects of nicotine in rats, but it has not been tested for this purpose in non-human primates. Therefore, we studied the effects of the first- and second-generation O-arylcarbamate-based FAAH inhibitors, URB597 (cyclohexyl carbamic acid 3'-carbamoyl-3-yl ester) and URB694 (6-hydroxy-[1,1'-biphenyl]-3-yl-cyclohexylcarbamate), in squirrel monkeys. Both FAAH inhibitors: (1) blocked FAAH activity in brain and liver, increasing levels of endogenous ligands for cannabinoid and α-type peroxisome proliferator-activated (PPAR-α) receptors; (2) shifted nicotine self-administration dose-response functions in a manner consistent with reduced nicotine reward; (3) blocked reinstatement of nicotine seeking induced by reexposure to either nicotine priming or nicotine-associated cues; and (4) had no effect on cocaine or food self-administration. The effects of FAAH inhibition on nicotine self-administration and nicotine priming-induced reinstatement were reversed by the PPAR-α antagonist, MK886. Unlike URB597, which was not self-administered by monkeys in an earlier study, URB694 was self-administered at a moderate rate. URB694 self-administration was blocked by pretreatment with an antagonist for either PPAR-α (MK886) or cannabinoid CB1 receptors (rimonabant). In additional experiments in rats, URB694 was devoid of THC-like or nicotine-like interoceptive effects under drug-discrimination procedures, and neither of the FAAH inhibitors induced dopamine release in the nucleus accumbens shell--consistent with their lack of robust reinforcing effects in monkeys. Overall, both URB597 and URB694 show promise for the initialization and maintenance of smoking cessation because of their ability to block the rewarding effects of nicotine and prevent nicotine priming-induced and cue-induced reinstatement. PMID:25754762

  15. Effects of Fatty Acid Amide Hydrolase (FAAH) Inhibitors in Non-Human Primate Models of Nicotine Reward and Relapse

    PubMed Central

    Justinova, Zuzana; Panlilio, Leigh V; Moreno-Sanz, Guillermo; Redhi, Godfrey H; Auber, Alessia; Secci, Maria E; Mascia, Paola; Bandiera, Tiziano; Armirotti, Andrea; Bertorelli, Rosalia; Chefer, Svetlana I; Barnes, Chanel; Yasar, Sevil; Piomelli, Daniele; Goldberg, Steven R

    2015-01-01

    Inhibition of the enzyme fatty acid amide hydrolase (FAAH) counteracts reward-related effects of nicotine in rats, but it has not been tested for this purpose in non-human primates. Therefore, we studied the effects of the first- and second-generation O-arylcarbamate-based FAAH inhibitors, URB597 (cyclohexyl carbamic acid 3'-carbamoyl-3-yl ester) and URB694 (6-hydroxy-[1,1'-biphenyl]-3-yl-cyclohexylcarbamate), in squirrel monkeys. Both FAAH inhibitors: (1) blocked FAAH activity in brain and liver, increasing levels of endogenous ligands for cannabinoid and α-type peroxisome proliferator-activated (PPAR-α) receptors; (2) shifted nicotine self-administration dose–response functions in a manner consistent with reduced nicotine reward; (3) blocked reinstatement of nicotine seeking induced by reexposure to either nicotine priming or nicotine-associated cues; and (4) had no effect on cocaine or food self-administration. The effects of FAAH inhibition on nicotine self-administration and nicotine priming-induced reinstatement were reversed by the PPAR-α antagonist, MK886. Unlike URB597, which was not self-administered by monkeys in an earlier study, URB694 was self-administered at a moderate rate. URB694 self-administration was blocked by pretreatment with an antagonist for either PPAR-α (MK886) or cannabinoid CB1 receptors (rimonabant). In additional experiments in rats, URB694 was devoid of THC-like or nicotine-like interoceptive effects under drug-discrimination procedures, and neither of the FAAH inhibitors induced dopamine release in the nucleus accumbens shell—consistent with their lack of robust reinforcing effects in monkeys. Overall, both URB597 and URB694 show promise for the initialization and maintenance of smoking cessation because of their ability to block the rewarding effects of nicotine and prevent nicotine priming-induced and cue-induced reinstatement. PMID:25754762

  16. Optimization of the Central Heterocycle of α-Ketoheterocycle Inhibitors of Fatty Acid Amide Hydrolase

    PubMed Central

    Garfunkle, Joie; Ezzili, Cyrine; Rayl, Thomas J.; Hochstatter, Dustin G.; Hwang, Inkyu; Boger, Dale L.

    2008-01-01

    The synthesis and evaluation of a refined series of α-ketoheterocycles based on the oxazole 2 (OL-135) incorporating systematic changes in the central heterocycle bearing a key set of added substituents are described. The nature of the central heterocycle, even within the systematic and minor perturbations explored herein, significantly influenced the inhibitor activity: 1,3,4-oxadiazoles and 1,2,4-oxadiazoles 9 > tetrazoles, the isomeric 1,2,4-oxadiazoles 10, 1,3,4-thiadiazoles > oxazoles including 2 > 1,2-diazines > thiazoles > 1,3,4-triazoles. Most evident in these trends is the observation that introduction of an additional heteroatom at position 4 (oxazole numbering, N > O > CH) substantially increases activity that may be attributed to a reduced destabilizing steric interaction at the FAAH active site. Added heterocycle substituents displaying well defined trends may be utilized to enhance the inhibitor potency and, more significantly, to enhance the inhibitor selectivity. These trends, exemplified herein, emerge from both enhancements in the FAAH activity and simultaneous disruption of binding affinity for competitive off-target enzymes. PMID:18630870

  17. The fatty acid synthase inhibitor triclosan: repurposing an anti-microbial agent for targeting prostate cancer

    PubMed Central

    Sadowski, Martin C.; Pouwer, Rebecca H.; Gunter, Jennifer H.; Lubik, Amy A.; Quinn, Ronald J.; Nelson, Colleen C.

    2014-01-01

    Inhibition of FASN has emerged as a promising therapeutic target in cancer, and numerous inhibitors have been investigated. However, severe pharmacological limitations have challenged their clinical testing. The synthetic FASN inhibitor triclosan, which was initially developed as a topical antibacterial agent, is merely affected by these pharmacological limitations. Yet, little is known about its mechanism in inhibiting the growth of cancer cells. Here we compared the cellular and molecular effects of triclosan in a panel of eight malignant and non-malignant prostate cell lines to the well-known FASN inhibitors C75 and orlistat, which target different partial catalytic activities of FASN. Triclosan displayed a superior cytotoxic profile with a several-fold lower IC50 than C75 or orlistat. Structure-function analysis revealed that alcohol functionality of the parent phenol is critical for inhibitory action. Rescue experiments confirmed that end product starvation was a major cause of cytotoxicity. Importantly, triclosan, C75 and orlistat induced distinct changes to morphology, cell cycle, lipid content and the expression of key enzymes of lipid metabolism, demonstrating that inhibition of different partial catalytic activities of FASN activates different metabolic pathways. These finding combined with its well-documented pharmacological safety profile make triclosan a promising drug candidate for the treatment of prostate cancer. PMID:25313139

  18. Tight binding inhibitors of N-acyl amino sugar and N-acyl amino acid deacetylases.

    PubMed

    Xu, Chengfu; Hall, Richard; Cummings, Jennifer; Raushel, Frank M

    2006-04-01

    Very potent inhibitors were synthesized for the enzymatic deacetylation of N-acetyl-d-glucosamine-6-phosphate (NagA) and N-acetyl-d-glutamate (DGD). The methyl phosphonamidate derivative of d-glucosamine-6-phosphate bound to N-acetyl-d-glucosamine-6-phosphate deacetylase with an equilibrium dissociation constant of 34 +/- 5 nM at pH 7.5 and an association rate constant of 6.1 x 103 M-1 s-1. The inhibition constant is 4000-fold lower than the Michaelis constant for the substrate N-acetyl-d-glucosamine-6-phosphate. N-Acetyl-d-glutamate deacetylase was inhibited by the methyl phosphonamidate derivative of d-glutamate with an inhibition constant of 460 +/- 70 pM at pH 7.6. The inhibitor bound to the enzyme 500 000-fold tighter than the Michaelis constant for N-formyl-d-glutamate. These compounds mimic the putative tetrahedral intermediate formed upon nucleophilic attack of an activated water molecule on the amide bond of the target substrate. These inhibitors should prove useful in the elucidation of the enzyme-substrate interactions for enzymes within the amidohydrolase superfamily. PMID:16568996

  19. Critical Factors Determining Dimerization of Human Antizyme Inhibitor*

    PubMed Central

    Su, Kuo-Liang; Liao, Ya-Fan; Hung, Hui-Chih; Liu, Guang-Yaw

    2009-01-01

    Ornithine decarboxylase (ODC) is the first enzyme involved in polyamine biosynthesis, and it catalyzes the decarboxylation of ornithine to putrescine. ODC is a dimeric enzyme, whereas antizyme inhibitor (AZI), a positive regulator of ODC that is homologous to ODC, exists predominantly as a monomer and lacks decarboxylase activity. The goal of this paper was to identify the essential amino acid residues that determine the dimerization of AZI. The nonconserved amino acid residues in the putative dimer interface of AZI (Ser-277, Ser-331, Glu-332, and Asp-389) were substituted with the corresponding residues in the putative dimer interface of ODC (Arg-277, Tyr-331, Asp-332, and Tyr-389, respectively). Analytical ultracentrifugation analysis was used to determine the size distribution of these AZI mutants. The size-distribution analysis data suggest that residue 331 may play a major role in the dimerization of AZI. Mutating Ser-331 to Tyr in AZI (AZI-S331Y) caused a shift from a monomer configuration to a dimer. Furthermore, in comparison with the single mutant AZI-S331Y, the AZI-S331Y/D389Y double mutant displayed a further reduction in the monomer-dimer Kd, suggesting that residue 389 is also crucial for AZI dimerization. Analysis of the triple mutant AZI-S331Y/D389Y/S277R showed that it formed a stable dimer (Kd value = 1.3 μm). Finally, a quadruple mutant, S331Y/D389Y/S277R/E332D, behaved as a dimer with a Kd value of ∼0.1 μm, which is very close to that of the human ODC enzyme. The quadruple mutant, although forming a dimer, could still be disrupted by antizyme (AZ), further forming a heterodimer, and it could rescue the AZ-inhibited ODC activity, suggesting that the AZ-binding ability of the AZI dimer was retained. PMID:19635796

  20. Hereditary angioedema and pregnancy: successful management of recurrent and frequent attacks of angioedema with C1-inhibitor concentrate, danazol and tranexamic acid – a case report

    PubMed Central

    Milingos, D S; Madhuvrata, P; Dean, J; Shetty, A; Campbell, D M

    2009-01-01

    Hereditary angioedema (HAE) is a rare but potentially life-threatening condition caused by deficiency of C1 esterase inhibitor. It is characterized by subcutaneous swelling in any part of the skin, gastrointestinal and respiratory tracts. We present the case of a pregnant woman with known HAE that deteriorated during pregnancy with frequent attacks that were managed successfully with danazol, tranexamic acid and regular intravenous administration of C1 esterase inhibitor.

  1. Boronic Acid Transition State Inhibitors Active against KPC and Other Class A β-Lactamases: Structure-Activity Relationships as a Guide to Inhibitor Design.

    PubMed

    Rojas, Laura J; Taracila, Magdalena A; Papp-Wallace, Krisztina M; Bethel, Christopher R; Caselli, Emilia; Romagnoli, Chiara; Winkler, Marisa L; Spellberg, Brad; Prati, Fabio; Bonomo, Robert A

    2016-03-01

    Boronic acid transition state inhibitors (BATSIs) are competitive, reversible β-lactamase inhibitors (BLIs). In this study, a series of BATSIs with selectively modified regions (R1, R2, and amide group) were strategically designed and tested against representative class A β-lactamases of Klebsiella pneumoniae, KPC-2 and SHV-1. Firstly, the R1 group of compounds 1a to 1c and 2a to 2e mimicked the side chain of cephalothin, whereas for compounds 3a to 3c, 4a, and 4b, the thiophene ring was replaced by a phenyl, typical of benzylpenicillin. Secondly, variations in the R2 groups which included substituted aryl side chains (compounds 1a, 1b, 1c, 3a, 3b, and 3c) and triazole groups (compounds 2a to 2e) were chosen to mimic the thiazolidine and dihydrothiazine ring of penicillins and cephalosporins, respectively. Thirdly, the amide backbone of the BATSI, which corresponds to the amide at C-6 or C-7 of β-lactams, was also changed to the following bioisosteric groups: urea (compound 3b), thiourea (compound 3c), and sulfonamide (compounds 4a and 4b). Among the compounds that inhibited KPC-2 and SHV-1 β-lactamases, nine possessed 50% inhibitory concentrations (IC50s) of ≤ 600 nM. The most active compounds contained the thiopheneacetyl group at R1 and for the chiral BATSIs, a carboxy- or hydroxy-substituted aryl group at R2. The most active sulfonamido derivative, compound 4b, lacked an R2 group. Compound 2b (S02030) was the most active, with acylation rates (k2/K) of 1.2 ± 0.2 × 10(4) M(-1) s(-1) for KPC-2 and 4.7 ± 0.6 × 10(3) M(-1) s(-1) for SHV-1, and demonstrated antimicrobial activity against Escherichia coli DH10B carrying blaSHV variants and blaKPC-2 or blaKPC-3 and against clinical strains of Klebsiella pneumoniae and E. coli producing different class A β-lactamase genes. At most, MICs decreased from 16 to 0.5 mg/liter. PMID:26729496

  2. The crystal structure and mechanism of orotidine 5'-monophosphate decarboxylase.

    PubMed

    Appleby, T C; Kinsland, C; Begley, T P; Ealick, S E

    2000-02-29

    The crystal structure of Bacillus subtilis orotidine 5'-monophosphate (OMP) decarboxylase with bound uridine 5'-monophosphate has been determined by multiple wavelength anomalous diffraction phasing techniques and refined to an R-factor of 19.3% at 2.4 A resolution. OMP decarboxylase is a dimer of two identical subunits. Each monomer consists of a triosephosphate isomerase barrel and contains an active site that is located across one end of the barrel and near the dimer interface. For each active site, most of the residues are contributed by one monomer with a few residues contributed from the adjacent monomer. The most highly conserved residues are located in the active site and suggest a novel catalytic mechanism for decarboxylation that is different from any previously proposed OMP decarboxylase mechanism. The uridine 5'-monophosphate molecule is bound to the active site such that the phosphate group is most exposed and the C5-C6 edge of the pyrimidine base is most buried. In the proposed catalytic mechanism, the ground state of the substrate is destabilized by electrostatic repulsion between the carboxylate of the substrate and the carboxylate of Asp60. This repulsion is reduced in the transition state by shifting negative charge from the carboxylate to C6 of the pyrimidine, which is close to the protonated amine of Lys62. We propose that the decarboxylation of OMP proceeds by an electrophilic substitution mechanism in which decarboxylation and carbon-carbon bond protonation by Lys62 occur in a concerted reaction. PMID:10681442

  3. Potentiated suppression of Dickkopf-1 in breast cancer by combined administration of the mevalonate pathway inhibitors zoledronic acid and statins.

    PubMed

    Göbel, Andy; Browne, Andrew J; Thiele, Stefanie; Rauner, Martina; Hofbauer, Lorenz C; Rachner, Tilman D

    2015-12-01

    The Wnt-inhibitor dickkopf-1 (DKK-1) promotes cancer-induced osteolytic bone lesions by direct inhibition of osteoblast differentiation and indirect activation of osteoclasts. DKK-1 is highly expressed in human breast cancer cells and can be suppressed by inhibitors of the mevalonate pathway such as statins and amino-bisphosphonates. However, supraphysiological concentrations are required to suppress DKK-1. We show that a sequential mevalonate pathway blockade using statins and amino-bisphosphonates suppresses DKK-1 more significantly than the individual agents alone. Thus, the reduction of the DKK-1 expression and secretion in the human osteotropic tumor cell lines MDA-MB-231, MDA-MET, and MDA-BONE by zoledronic acid was potentiated by the combination with low concentrations of statins (atorvastatin, simvastatin, and rosuvastatin) by up to 75% (p < 0.05). The specific rescue of prenylation using farnesyl pyrophosphate or geranylgeranyl pyrophosphate revealed that these effects were mediated by suppressed geranylgeranylation rather than by suppressed farnesylation. Moreover, combining low concentrations of statins (1 µM atorvastatin or 0.25 µM simvastatin) and zoledronic acid at low concentrations resulted in an at least 50% reversal of breast cancer-derived DKK-1-mediated inhibition of osteogenic markers in C2C12 cells (p < 0.05). Finally, the intratumoral injection of atorvastatin and zoledronic acid in as subcutaneous MDA-MB-231 mouse model reduced the serum level of human DKK-1 by 25% compared to untreated mice. Hence our study reveals that a sequential mevalonate pathway blockade allows for the combined use of low concentration of statins and amino-bisphosphonates. This combination still significantly suppresses breast cancer-derived DKK-1 to levels where it can no longer inhibit Wnt-mediated osteoblast differentiation. PMID:26515701

  4. 4-Hydroxybenzoic acid derivatives as HDAC6-specific inhibitors modulating microtubular structure and HSP90α chaperone activity against prostate cancer.

    PubMed

    Seidel, Carole; Schnekenburger, Michael; Mazumder, Aloran; Teiten, Marie-Hélène; Kirsch, Gilbert; Dicato, Mario; Diederich, Marc

    2016-01-01

    Histone deacetylase (HDAC)6 is a unique isoenzyme targeting specific substrates including α-tubulin and heat shock protein (HSP)90. HDAC6 is involved in protein trafficking and degradation, cell shape and migration. Deregulation of HDAC6 activity is associated with a variety of diseases including cancer leading to a growing interest for developing HDAC6 inhibitors. Here, we identified two new structurally related 4-hydroxybenzoic acids as selective HDAC6 inhibitors reducing proliferation, colony and spheroid formation as well as viability of prostate cancer cells. Both compounds strongly enhanced α-tubulin acetylation leading to remodeling of microtubular organization. Furthermore, 4-hydroxybenzoic acids decreased HSP90α regulation of the human androgen receptor in prostate cancer cells by increasing HSP90α acetylation levels. Collectively, our data support the potential of 4-hydroxybenzoic acid derivatives as HDAC6-specific inhibitors with anti-cancer properties. PMID:26549368

  5. Synthesis and structure-activity relationship studies of O-biphenyl-3-yl carbamates as peripherally restricted fatty acid amide hydrolase inhibitors.

    PubMed

    Moreno-Sanz, Guillermo; Duranti, Andrea; Melzig, Laurin; Fiorelli, Claudio; Ruda, Gian Filippo; Colombano, Giampiero; Mestichelli, Paola; Sanchini, Silvano; Tontini, Andrea; Mor, Marco; Bandiera, Tiziano; Scarpelli, Rita; Tarzia, Giorgio; Piomelli, Daniele

    2013-07-25

    The peripherally restricted fatty acid amide hydrolase (FAAH) inhibitor URB937 (3, cyclohexylcarbamic acid 3'-carbamoyl-6-hydroxybiphenyl-3-yl ester) is extruded from the brain and spinal cord by the Abcg2 efflux transporter. Despite its inability to enter the central nervous system (CNS), 3 exerts profound antinociceptive effects in mice and rats, which result from the inhibition of FAAH in peripheral tissues and the consequent enhancement of anandamide signaling at CB1 cannabinoid receptors localized on sensory nerve endings. In the present study, we examined the structure-activity relationships (SAR) for the biphenyl region of compound 3, focusing on the carbamoyl and hydroxyl groups in the distal and proximal phenyl rings. Our SAR studies generated a new series of peripherally restricted FAAH inhibitors and identified compound 35 (cyclohexylcarbamic acid 3'-carbamoyl-5-hydroxybiphenyl-3-yl ester) as the most potent brain-impermeant FAAH inhibitor disclosed to date. PMID:23822179

  6. Molecular cloning and sequence analysis of the cDNA encoding rat liver cysteine sulfinate decarboxylase (CSD).

    PubMed

    Reymond, I; Sergeant, A; Tappaz, M

    1996-06-01

    The taurine biosynthesis enzyme, cysteine sulfinate decarboxylase (CSD), was purified to homogeneity from rat liver. Three CSD peptides generated by tryptic cleavage were isolated and partially sequenced. Two of them showed a marked homology with glutamate decarboxylase and their respective position on the CSD amino acid sequence was postulated accordingly. Using appropriate degenerated primers derived from these two peptides, a PCR amplified DNA fragment was generated from liver poly(A)+ mRNA, cloned and used as a probe to screen a rat liver cDNA library. Three cDNAs, length around 1800 bp, were isolated which all contained an open reading frame (ORF) encoding a 493 amino acid protein with a calculated molecular mass of 55.2 kDa close to the experimental values for CSD. The encoded protein contained the sequence of the three peptides isolated from homogenous liver CSD. Our data confirm and significantly extend those recently published (Kaisaki et al. (1995) Biochim. Biophys. Acta 1262, 79-82). Indeed, an additional base pair found 1371 bp downstream from the initiation codon led to a shift in the open reading frame which extended the carboxy-terminal end by 15 amino acid residues and altogether modified 36 amino acids. The validity of this correction is supported by the finding that the corrected reading frame encoded a peptide issued from CSD tryptic cleavage that was not encoded anywhere in the CSD sequence previously reported. PMID:8679699

  7. Structural requirements for novel coenzyme-substrate derivatives to inhibit intracellular ornithine decarboxylase and cell proliferation.

    PubMed

    Wu, Fang; Gehring, Heinz

    2009-02-01

    Creating transition-state mimics has proven to be a powerful strategy in developing inhibitors to treat malignant diseases in several cases. In the present study, structurally diverse coenzyme-substrate derivatives mimicking this type for pyridoxal 5'-phosphate-dependent human ornithine decarboxylase (hODC), a potential anticancer target, were designed, synthesized, and tested to elucidate the structural requirements for optimal inhibition of intracellular ODC as well as of tumor cell proliferation. Of 23 conjugates, phosphopyridoxyl- and pyridoxyl-L-tryptophan methyl ester (pPTME, PTME) proved significantly more potent in suppression proliferation (IC(50) up to 25 microM) of glioma cells (LN229) than alpha-DL-difluoromethylornithine (DFMO), a medically used irreversible inhibitor of ODC. In agreement with molecular modeling predictions, the inhibitory action of pPTME and PTME toward intracellular ODC of LN229 cells exceeded that of the previous designed lead compound POB. The inhibitory active compounds feature hydrophobic side chain fragments and a kind of polyamine motif (-NH-(CH(X))(4)-NH-). In addition, they induce, as polyamine analogs often do, the activity of the polyamine catabolic enzymes polyamine oxidase and spermine/spermidine N(1)-acetyltransferase up to 250 and 780%, respectively. The dual-action mode of these compounds in LN229 cells affects the intracellular polyamine metabolism and might underlie the more favorable cell proliferation inhibition in comparison with DFMO. PMID:18922879

  8. Fermentation inhibitors and their recovery from acid wood hydrolyzates as chemicals of value

    SciTech Connect

    Tran, Hao Cao.

    1986-01-01

    The principal objective of this study was to demonstrate the technical feasibility of fermentation inhibition removal from acid hydrolyzates of lignocellulosic materials and recovery of the by-products of acid hydrolysis as chemicals of value. The acid hydrolyzates of mixed hardwoods were produced from the continuous flow demonstration unit (CFDU) at the University of California Forest Products Laboratory. Two separate liquid product streams were the prehydrolyzate (S1H) and the second stage hydrolyzate (S2H). Candida utilis NRRL Y-900 and Saccharomyces cerevisiae NRRL 2034 were used to monitor the fermentability of these two product streams, respectively. Two pretreatment methods were investigated in detail: flashing and solvent extraction. For the S1H, flashing was adequate to enable cell production with Candida utilis. The S2H rehired solvent extraction to ensure ethanolic fermentation at high concentrations of glucose (12% or higher). A solvent was selected for the extraction process and process flow designs were proposed to recycle the solvent and isolate commercial by-products, including furfural, methanol, acetic acid and, potentially, formic acid, levulinic acid and 5-hydroxymethylfurfural.

  9. Sterculic Acid and Its Analogues Are Potent Inhibitors of Toxoplasma gondii.

    PubMed

    Hao, Pan; Alaraj, Intisar Q M; Dulayymi, Juma'a R Al; Baird, Mark S; Liu, Jing; Liu, Qun

    2016-04-01

    Toxoplasmosis is a serious disease caused by Toxoplasma gondii, one of the most widespread parasites in the world. Lipid metabolism is important in the intracellular stage of T. gondii. Stearoyl-CoA desaturase (SCD), a key enzyme for the synthesis of unsaturated fatty acid is predicted to exist in T. gondii. Sterculic acid has been shown to specifically inhibit SCD activity. Here, we examined whether sterculic acid and its methyl ester analogues exhibit anti-T. gondii effects in vitro. T. gondii-infected Vero cells were disintegrated at 36 hr because of the propagation and egress of intracellular tachyzoites. All test compounds inhibited tachyzoite propagation and egress, reducing the number of ruptured Vero cells by the parasites. Sterculic acid and the methyl esters also inhibited replication of intracellular tachyzoites in HFF cells. Among the test compounds, sterculic acid showed the most potent activity against T. gondii, with an EC50 value of 36.2 μM, compared with EC50 values of 248-428 μM for the methyl esters. Our study demonstrated that sterculic acid and its analogues are effective in inhibition of T. gondii growth in vitro, suggesting that these compounds or analogues targeting SCD could be effective agents for the treatment of toxoplasmosis. PMID:27180571

  10. Sterculic Acid and Its Analogues Are Potent Inhibitors of Toxoplasma gondii

    PubMed Central

    Hao, Pan; Alaraj, Intisar Q. M.; Dulayymi, Juma’a R. Al; Baird, Mark S.; Liu, Jing; Liu, Qun

    2016-01-01

    Toxoplasmosis is a serious disease caused by Toxoplasma gondii, one of the most widespread parasites in the world. Lipid metabolism is important in the intracellular stage of T. gondii. Stearoyl-CoA desaturase (SCD), a key enzyme for the synthesis of unsaturated fatty acid is predicted to exist in T. gondii. Sterculic acid has been shown to specifically inhibit SCD activity. Here, we examined whether sterculic acid and its methyl ester analogues exhibit anti-T. gondii effects in vitro. T. gondii-infected Vero cells were disintegrated at 36 hr because of the propagation and egress of intracellular tachyzoites. All test compounds inhibited tachyzoite propagation and egress, reducing the number of ruptured Vero cells by the parasites. Sterculic acid and the methyl esters also inhibited replication of intracellular tachyzoites in HFF cells. Among the test compounds, sterculic acid showed the most potent activity against T. gondii, with an EC50 value of 36.2 μM, compared with EC50 values of 248-428 μM for the methyl esters. Our study demonstrated that sterculic acid and its analogues are effective in inhibition of T. gondii growth in vitro, suggesting that these compounds or analogues targeting SCD could be effective agents for the treatment of toxoplasmosis. PMID:27180571

  11. Snake venom toxins. The amino acid sequence of toxin Vi2, a homologue of pancreatic trypsin inhibitor, from Dendroaspis polylepis polylepis (black mamba) venom.

    PubMed

    Strydom, D J

    1977-04-25

    The amino acid sequence of venom component Vi2, a protein of low toxicity from Dendroaspis polylepis polylepis venom was determined by automatic sequence analysis in combination with sequence studies on tryptic peptides. This protein, the most retarded fraction of this venom on a cation-exchange resin, is a homologue of bovine pancreatic trypsin inhibitor consisting of a single chain of 57 amino acid residues containing six half-cystine residues. The active site lysyl residue of bovine trypsin inhibitor is conserved in Vi2 although large differences are found in the rest of the molecule. PMID:857902

  12. Small-Molecule Inhibitors of the Pseudaminic Acid Biosynthetic Pathway: Targeting Motility as a Key Bacterial Virulence Factor

    PubMed Central

    Ménard, Robert; Schoenhofen, Ian C.; Tao, Limei; Aubry, Annie; Bouchard, Patrice; Reid, Christopher W.; Lachance, Paule; Twine, Susan M.; Fulton, Kelly M.; Cui, Qizhi; Hogues, Hervé; Purisima, Enrico O.

    2014-01-01

    Helicobacter pylori is motile by means of polar flagella, and this motility has been shown to play a critical role in pathogenicity. The major structural flagellin proteins have been shown to be glycosylated with the nonulosonate sugar, pseudaminic acid (Pse). This glycan is unique to microorganisms, and the process of flagellin glycosylation is required for H. pylori flagellar assembly and consequent motility. As such, the Pse biosynthetic pathway offers considerable potential as an antivirulence drug target, especially since motility is required for H. pylori colonization and persistence in the host. This report describes screening the five Pse biosynthetic enzymes for small-molecule inhibitors using both high-throughput screening (HTS) and in silico (virtual screening [VS]) approaches. Using a 100,000-compound library, 1,773 hits that exhibited a 40% threshold inhibition at a 10 μM concentration were identified by HTS. In addition, VS efforts using a 1.6-million compound library directed at two pathway enzymes identified 80 hits, 4 of which exhibited reasonable inhibition at a 10 μM concentration in vitro. Further secondary screening which identified 320 unique molecular structures or validated hits was performed. Following kinetic studies and structure-activity relationship (SAR) analysis of selected inhibitors from our refined list of 320 compounds, we demonstrated that three inhibitors with 50% inhibitory concentrations (IC50s) of approximately 14 μM, which belonged to a distinct chemical cluster, were able to penetrate the Gram-negative cell membrane and prevent formation of flagella. PMID:25267679

  13. Suppression of IL-12p40-related regulatory cytokines by suberoylanilide hydroxamic acid an inhibitor of histone deacetylases.

    PubMed

    Dobreva, Zlatka Georgieva; Grigorov, Boncho Grigorov; Stanilova, Spaska Angelova

    2016-08-01

    Small molecule inhibitors of histone deacetylases (HDACs) are a new class drugs used in clinical trials for the treatment of various malignancies. Emerging evidence suggest that HDAC inhibitors may also have anti-inflammatory properties, although the molecular mechanisms remain poorly defined. Our study investigates the effect of the HDACs inhibitor suberoylanilide hydroxamic acid (SAHA) on the expression of IL-12p40-related cytokines. For this purpose, human peripheral blood mononuclear cells (PBMC) were stimulated with LPS and C3bgp with or without SAHA. IL-12p40, IL-12p35 and IL-23p19 mRNA was determined at 6 h by qRT-PCR. Cytokine levels were determined in culture supernatants at 6 and 24 h, by ELISA. SAHA significantly inhibited IL-12p40 and IL-23p19 mRNA synthesis and did not change IL-12p35 mRNA transcription. Early at 6 h, we detected significantly decreased IL-12p40 and IL-23, but not IL-12p70 protein production in cultures treated with SAHA. Results also showed that the suppression of IL-12p40-related cytokines was clearly defined at 24 h. However, this suppression was less pronounced regarding IL-12p70. The present study showed that SAHA suppressed the gene expression of IL-23p19 stronger than the expression of IL-12p35, as well as the synthesis of IL-23 compared to that of IL-12p70. We suggest that this inhibitory effect of SAHA may be beneficial during treatment of inflammatory and autoimmune diseases mediated by Th17 immune response. PMID:27240992

  14. Structure of 'linkerless' hydroxamic acid inhibitor-HDAC8 complex confirms the formation of an isoform-specific subpocket.

    PubMed

    Tabackman, Alexa A; Frankson, Rochelle; Marsan, Eric S; Perry, Kay; Cole, Kathryn E

    2016-09-01

    Histone deacetylases (HDACs) catalyze the hydrolysis of acetylated lysine side chains in histone and non-histone proteins, and play a critical role in the regulation of many biological processes, including cell differentiation, proliferation, senescence, and apoptosis. Aberrant HDAC activity is associated with cancer, making these enzymes important targets for drug design. In general, HDAC inhibitors (HDACi) block the proliferation of tumor cells by inducing cell differentiation, cell cycle arrest, and/or apoptosis, and comprise some of the leading therapies in cancer treatments. To date, four HDACi have been FDA approved for the treatment of cancers: suberoylanilide hydroxamic acid (SAHA, Vorinostat, Zolinza®), romidepsin (FK228, Istodax®), belinostat (Beleodaq®), and panobinostat (Farydak®). Most current inhibitors are pan-HDACi, and non-selectively target a number of HDAC isoforms. Six previously reported HDACi were rationally designed, however, to target a unique sub-pocket found only in HDAC8. While these inhibitors were indeed potent against HDAC8, and even demonstrated specificity for HDAC8 over HDACs 1 and 6, there were no structural data to confirm the mode of binding. Here we report the X-ray crystal structure of Compound 6 complexed with HDAC8 to 1.98Å resolution. We also describe the use of molecular docking studies to explore the binding interactions of the other 5 related HDACi. Our studies confirm that the HDACi induce the formation of and bind in the HDAC8-specific subpocket, offering insights into isoform-specific inhibition. PMID:27374062

  15. High resolution crystal structure of rat long chain hydroxy acid oxidase in complex with the inhibitor 4-carboxy-5-[(4-chlorophenyl)sulfanyl]-1, 2, 3-thiadiazole. Implications for inhibitor specificity and drug design

    SciTech Connect

    Chen, Zhi-wei; Vignaud, Caroline; Jaafar, Adil; Lévy, Bernard; Guéritte, Françoise; Guénard, Daniel; Lederer, Florence; Mathews, F. Scott

    2012-05-24

    Long chain hydroxy acid oxidase (LCHAO) is responsible for the formation of methylguanidine, a toxic compound with elevated serum levels in patients with chronic renal failure. Its isozyme glycolate oxidase (GOX), has a role in the formation of oxalate, which can lead to pathological deposits of calcium oxalate, in particular in the disease primary hyperoxaluria. Inhibitors of these two enzymes may have therapeutic value. These enzymes are the only human members of the family of FMN-dependent L-2-hydroxy acid-oxidizing enzymes, with yeast flavocytochrome b{sub 2} (Fcb2) among its well studied members. We screened a chemical library for inhibitors, using in parallel rat LCHAO, human GOX and the Fcb2 flavodehydrogenase domain (FDH). Among the hits was an inhibitor, CCPST, with an IC{sub 50} in the micromolar range for all three enzymes. We report here the crystal structure of a complex between this compound and LCHAO at 1.3 {angstrom} resolution. In comparison with a lower resolution structure of this enzyme, binding of the inhibitor induces a conformational change in part of the TIM barrel loop 4, as well as protonation of the active site histidine. The CCPST interactions are compared with those it forms with human GOX and those formed by two other inhibitors with human GOX and spinach GOX. These compounds differ from CCPST in having the sulfur replaced with a nitrogen in the five-membered ring as well as different hydrophobic substituents. The possible reason for the {approx}100-fold difference in affinity between these two series of inhibitors is discussed. The present results indicate that specificity is an issue in the quest for therapeutic inhibitors of either LCHAO or GOX, but they may give leads for this quest.

  16. Effects of Bafilomycin A1 and Metabolic Inhibitors on the Maintenance of Vacuolar Acidity in Maize Root Hair Cells.

    PubMed

    Brauer, D.; Uknalis, J.; Triana, R.; Shachar-Hill, Y.; Tu, S. I.

    1997-03-01

    Proton pumps of tonoplast membranes have been studied extensively in vitro, but data concerning their regulation in vivo are lacking. Effects of either anoxia, or the addition of KCN, 2-deoxy-d-glucose (deoxy-glucose), or bafilomycin-A1 (BAF) on vacuolar pH of maize (Zea mays L.) root hair cells were followed by fluorescence microscopy after loading of 2[prime]7[prime]-bis-(2-carboxyethyl)-5-(and-6) carboxyfluorescein. Root hair cells were able to maintain vacuolar acidity for at least 2 h in the presence of either 10 mM KCN or 50 mM deoxy-glucose or during anoxia. Treatments with either deoxy-glucose or KCN reduced total tissue ATP more than anoxia. ADP accumulated during anoxia and treatment with KCN as detected by in vivo 31P-NMR spectroscopy, but not during deoxy-glucose treatment. With control roots and roots treated with deoxy-glucose, the presence of BAF, a specific inhibitor of the V-type ATPase, caused alkalization of the vacuolar pH. However, either in the presence of KCN or under anoxic conditions, BAF was relatively ineffective in dissipating vacuolar acidity. Therefore, under anoxia or in the presence of KCN, unlike the situation with air or deoxy-glucose, the V-type ATPase apparently is not required for maintenance of vacuolar acidity. PMID:12223644

  17. Aryl-acetic and cinnamic acids as lipoxygenase inhibitors with antioxidant, anti-inflammatory, and anticancer activity.

    PubMed

    Hadjipavlou-Litina, Dimitra; Pontiki, Eleni

    2015-01-01

    Cinnamic acids have been identified as interesting compounds with cytotoxic, anti-inflammatory, and antioxidant properties. Lipoxygenase pathway, catalyzing the first two steps of the transformation of arachidonic acid into leukotrienes is implicated in several processes such as cell differentiation, inflammation and carcinogenesis. Development of drugs that interfere with the formation or effects of these metabolites would be important for the treatment of various diseases like asthma, psoriasis, ulcerative colitis, rheumatoid arthritis, atherosclerosis, cancer, and blood vessel disorders. Till now, asthma consists of the only pathological case in which improvement has been shown by lipoxygenase LO inhibitors. Thus, the research has been directed towards the development of drugs that interfere with the formation of leukotrienes. In order to explore the anti-inflammatory and cytotoxic effects of antioxidant acrylic/cinnamic acids a series of derivatives bearing the appropriate moieties have been synthesized via the Knoevenagel condensation and evaluated for their biological activities. The compounds have shown important antioxidant activity, anti-inflammatory activity and very good inhibition of soybean lipoxygenase while some of them were tested for their anticancer activity. PMID:25323520

  18. 2-Benzazolyl-4-Piperazin-1-Ylsulfonylbenzenecarbohydroxamic Acids as Novel Selective Histone Deacetylase-6 Inhibitors with Antiproliferative Activity

    PubMed Central

    Wang, Lei; Kofler, Marina; Brosch, Gerald; Melesina, Jelena; Sippl, Wolfgang; Martinez, Elisabeth D.; Easmon, Johnny

    2015-01-01

    We have screened our compound collection in an established cell based assay that measures the derepression of an epigenetically silenced transgene, the locus derepression assay. The screen led to the identification of 4-[4-(1-methylbenzimidazol-2-yl)piperazin-1-yl]sulfonylbenzenecarbohydroxamic acid (9b) as an active which was found to inhibit HDAC1. In initial structure activity relationships study, the 1-methylbenzimidazole ring was replaced by the isosteric heterocycles benzimidazole, benzoxazole, and benzothiazole and the position of the hydroxamic acid substituent on the phenyl ring was varied. Whereas compounds bearing a para substituted hydroxamic acid (9a-d) were active HDAC inhibitors, the meta substituted analogues (8a-d) were appreciably inactive. Compounds 9a-d selectively inhibited HDAC6 (IC50 = 0.1–1.0μM) over HDAC1 (IC50 = 0.9–6μM) and moreover, also selectively inhibited the growth of lung cancer cells vs. patient matched normal cells. The compounds induce a cell cycle arrest in the S-phase while induction of apoptosis is neglible as compared to controls. Molecular modeling studies uncovered that the MM-GBSA energy for interaction of 9a-d with HDAC6 was higher than for HDAC1 providing structural rationale for the HDAC6 selectivity. PMID:26698121

  19. Biophysical Property and Broad Anti-HIV Activity of Albuvirtide, a 3-Maleimimidopropionic Acid-Modified Peptide Fusion Inhibitor

    PubMed Central

    Chong, Huihui; Yao, Xue; Zhang, Chao; Cai, Lifeng; Cui, Sheng; Wang, Youchun; He, Yuxian

    2012-01-01

    Albuvirtide (ABT) is a 3-maleimimidopropionic acid (MPA)-modified peptide HIV fusion inhibitor that can irreversibly conjugate to serum albumin. Previous studies demonstrated its in vivo long half-life and potent anti-HIV activity. Here, we focused to characterize its biophysical properties and evaluate its antiviral spectrum. In contrast to T20 (Enfuvirtide, Fuzeon), ABT was able to form a stable α-helical conformation with the target sequence and block the fusion-active six-helix bundle (6-HB) formation in a dominant-negative manner. It efficiently inhibited HIV-1 Env-mediated cell membrane fusion and virus entry. A large panel of 42 HIV-1 pseudoviruses with different genotypes were constructed and used for the antiviral evaluation. The results showed that ABT had potent inhibitory activity against the subtypes A, B and C that predominate the worldwide AIDS epidemics, and subtype B′, CRF07_BC and CRF01_AE recombinants that are currently circulating in China. Furthermore, ABT was also highly effective against HIV-1 variants resistant to T20. Taken together, our data indicate that the chemically modified peptide ABT can serve as an ideal HIV-1 fusion inhibitor. PMID:22403678

  20. sym-Trisubstituted 1,3,5-Triazine Derivatives as Promising Organic Corrosion Inhibitors for Steel in Acidic Solution.

    PubMed

    El-Faham, Ayman; Dahlous, Kholood A; Al Othman, Zeid A; Al-Lohedan, Hamad A; El-Mahdy, Gamal A

    2016-01-01

    Triazine derivatives, namely, 2,4,6-tris(quinolin-8-yloxy)-1,3,5-triazine (T3Q), N²,N⁴,N⁶-tris(pyridin-2-ylmethyl)-1,3,5-triazine-2,4,6-triamine (T3AMPy) and 2,2',2''-[(1,3,5-triazine-2,4,6-triyl)tris(azanediyl)] tris(ethan-1-ol) (T3EA) were synthesized and their inhibition of steel corrosion in hydrochloric acid solution was investigated using electrochemical techniques. The corrosion protection of the prepared compounds increased with increasing concentration and reached up to 98% at 250 ppm. The adsorption of T3Q, T3AMPy, and T3EA on the steel surface was in accordance with the Langmuir adsorption isotherm. The electrochemical results revealed that T3Q, T3AMPy and T3EA act as excellent organic inhibitors and can labeled as mixed type inhibitors. The efficiencies of the tested compounds were affected by the nature of the side chain present in the triazine ring, where T3EA gave the least inhibition while T3Q and T3AMPy gave higher and almost the same inhibition effects. The inhibition efficiencies obtained from the different electrochemical techniques were in good agreement. PMID:27043517

  1. Salicylic Acid Based Small Molecule Inhibitor for the Oncogenic Src Homology-2 Domain Containing Protein Tyrosine Phosphatase-2 (SHP2)

    SciTech Connect

    Zhang, Xian; He, Yantao; Liu, Sijiu; Yu, Zhihong; Jiang, Zhong-Xing; Yang, Zhenyun; Dong, Yuanshu; Nabinger, Sarah C.; Wu, Li; Gunawan, Andrea M.; Wang, Lina; Chan, Rebecca J.; Zhang, Zhong-Yin

    2010-08-13

    The Src homology-2 domain containing protein tyrosine phosphatase-2 (SHP2) plays a pivotal role in growth factor and cytokine signaling. Gain-of-function SHP2 mutations are associated with Noonan syndrome, various kinds of leukemias, and solid tumors. Thus, there is considerable interest in SHP2 as a potential target for anticancer and antileukemia therapy. We report a salicylic acid based combinatorial library approach aimed at binding both active site and unique nearby subpockets for enhanced affinity and selectivity. Screening of the library led to the identification of a SHP2 inhibitor II-B08 (compound 9) with highly efficacious cellular activity. Compound 9 blocks growth factor stimulated ERK1/2 activation and hematopoietic progenitor proliferation, providing supporting evidence that chemical inhibition of SHP2 may be therapeutically useful for anticancer and antileukemia treatment. X-ray crystallographic analysis of the structure of SHP2 in complex with 9 reveals molecular determinants that can be exploited for the acquisition of more potent and selective SHP2 inhibitors.

  2. Pharmacophore Modeling and Virtual Screening for Novel Acidic Inhibitors of Microsomal Prostaglandin E2 Synthase-1 (mPGES-1)

    PubMed Central

    2011-01-01

    Microsomal prostaglandin E2 synthase-1 (mPGES-1) catalyzes prostaglandin E2 formation and is considered as a potential anti-inflammatory pharmacological target. To identify novel chemical scaffolds active on this enzyme, two pharmacophore models for acidic mPGES-1 inhibitors were developed and theoretically validated using information on mPGES-1 inhibitors from literature. The models were used to screen chemical databases supplied from the National Cancer Institute (NCI) and the Specs. Out of 29 compounds selected for biological evaluation, nine chemically diverse compounds caused concentration-dependent inhibition of mPGES-1 activity in a cell-free assay with IC50 values between 0.4 and 7.9 μM, respectively. Further pharmacological characterization revealed that also 5-lipoxygenase (5-LO) was inhibited by most of these active compounds in cell-free and cell-based assays with IC50 values in the low micromolar range. Together, nine novel chemical scaffolds inhibiting mPGES-1 are presented that may possess anti-inflammatory properties based on the interference with eicosanoid biosynthesis. PMID:21466167

  3. Populus nigra (Salicaceae) absolute rich in phenolic acids, phenylpropanoïds and flavonoids as a new potent tyrosinase inhibitor.

    PubMed

    Maack, A; Pegard, A

    2016-06-01

    The purpose of this study was to evaluate the tyrosinase inhibitory capacity of Populus nigra buds absolute (PBA) and compare it to kojic acid (KA), controversial reference tyrosinase inhibitor. Populus nigra buds were extracted with hexane and ethanol to obtain PBA. The inhibitory effect of this absolute was first tested on the mushroom Agaricus bisporus tyrosinase. Then the depigmenting potential of PBA was tested on B16F10 murine melanocytes by assaying the activity of tyrosinase and melanin content. Consecutively, a microscopic analysis of intracellular melanin granules was performed. Finally, melanised reconstructed human epidermis (RHE) were used to assess the lightening potential activity of this PBA on human skin. Results show that PBA inhibits A. bisporus tyrosinase (IC50=77±8ppm) and inhibits melanocytes B16F10 tyrosinase (IC50=27±1ppm). PBA decreases intracellular melanin levels, with 50% loss at 39±9ppm. Finally, PBA at 1000ppm lightens RHE and decreases their melanin content of 20%. PBA is a strong inhibitor of tyrosinase and reduces melanogenesis in melanocytes B16F10. Thus, PBA has potential applications in skin-lightening cosmetics. PMID:27091790

  4. Tetrabromocinnamic acid (TBCA) and related compounds represent a new class of specific protein kinase CK2 inhibitors.

    PubMed

    Pagano, Mario A; Poletto, Giorgia; Di Maira, Giovanni; Cozza, Giorgio; Ruzzene, Maria; Sarno, Stefania; Bain, Jenny; Elliott, Matthew; Moro, Stefano; Zagotto, Giuseppe; Meggio, Flavio; Pinna, Lorenzo A

    2007-01-01

    Abnormally high constitutive activity of protein kinase CK2, levels of which are elevated in a variety of tumours, is suspected to underlie its pathogenic potential. The most widely employed CK2 inhibitor is 4,5,6,7-tetrabromobenzotriazole (TBB), which exhibits a comparable efficacy toward another kinase, DYRK1 a. Here we describe the development of a new class of CK2 inhibitors, conceptually derived from TBB, which have lost their potency toward DYRK1 a. In particular, tetrabromocinnamic <