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Sample records for acid decarboxylase gad

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

    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

  2. Development of diagnostic RI test method for antiglutamic acid decarboxylase (GAD) in SMS and IDDM patients

    Ota, Mitsuhiro; Ota, Kiyoe; Nishimura, Masataka; Ma Jie; Obayashi, Hiroshi; Saida, Takahiko [Utano National Hospital, Kyoto (Japan)

    2000-02-01

    Western blotting with antigens purified using its specific antibody bound column has demonstrated that patients with Stiff-man syndrome (SMS) and insulin-dependent diabetic mellitus (IDDM) were both positive for anti-GAD antibody. Further, anti-GAD antibodies from various animal brains were characterized using GAD 65 and GAD 67 peptide antibody. The antibody against the anti-N-terminal peptide inhibited the enzyme activity of GAD, suggesting that the active site of GAD might exist in the N-terminal region. Development of a new detection method for anti-GAD antibody was attempted and the amount of GAD protein bound to protein G resin was determined based on the activity to release {sup 14}CO{sub 2} from {sup 14}C glutamic acid. In addition, solid-phase RIA method was developed using GAD purified by the anti-peptide antibody affinity column. The positive detection rate for GAD antibody was 39% for the enzymatic method and 56% for the solid-phase RIA method. To develop a further sensitive detection method for GAD antibody, construction of recombinant GAD was attempted and two GAD65s different in molecular size were constructed using pMal-c vector. Thus obtained antibodies against anti-N-terminal peptides were separately responded to GAD65 and GAD67 isoforms in the rat, mouse and bovine brains, whereas the carboxy-terminal antibodies were reactive to both isoforms together. Therefore, it became possible to make purification of GAD65 and GAD67 by the use of the two N-terminal peptide antibodies. Further, it became possible to purify GAD as a mixture of both isoforms. However, the yield of purification using anti-affinity column was still unsatisfactory ( several percent) and the GAD preparation obtained had little activity. The positive detection by the solid-phase RIA method was 50% for SMS patients and 56% for IDDM ones, indicating that this method was superior to the previous enzyme method. The protein A method in which labeled human recombinant GAD65 was used to

  3. Development of diagnostic RI test method for antiglutamic acid decarboxylase (GAD) in SMS and IDDM patients

    Western blotting with antigens purified using its specific antibody bound column has demonstrated that patients with Stiff-man syndrome (SMS) and insulin-dependent diabetic mellitus (IDDM) were both positive for anti-GAD antibody. Further, anti-GAD antibodies from various animal brains were characterized using GAD 65 and GAD 67 peptide antibody. The antibody against the anti-N-terminal peptide inhibited the enzyme activity of GAD, suggesting that the active site of GAD might exist in the N-terminal region. Development of a new detection method for anti-GAD antibody was attempted and the amount of GAD protein bound to protein G resin was determined based on the activity to release 14CO2 from 14C glutamic acid. In addition, solid-phase RIA method was developed using GAD purified by the anti-peptide antibody affinity column. The positive detection rate for GAD antibody was 39% for the enzymatic method and 56% for the solid-phase RIA method. To develop a further sensitive detection method for GAD antibody, construction of recombinant GAD was attempted and two GAD65s different in molecular size were constructed using pMal-c vector. Thus obtained antibodies against anti-N-terminal peptides were separately responded to GAD65 and GAD67 isoforms in the rat, mouse and bovine brains, whereas the carboxy-terminal antibodies were reactive to both isoforms together. Therefore, it became possible to make purification of GAD65 and GAD67 by the use of the two N-terminal peptide antibodies. Further, it became possible to purify GAD as a mixture of both isoforms. However, the yield of purification using anti-affinity column was still unsatisfactory ( several percent) and the GAD preparation obtained had little activity. The positive detection by the solid-phase RIA method was 50% for SMS patients and 56% for IDDM ones, indicating that this method was superior to the previous enzyme method. The protein A method in which labeled human recombinant GAD65 was used to precipitate 125-I GAD

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

    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.

  5. 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.

    I-Ting Chow

    Full Text Available 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 GAD65 121-140 and GAD65 250-266 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 GAD65 121-140 and GAD65 250-266 carried a Th1-dominant phenotype, with some of the GAD65 121-140-specific T cell clones producing IL-17. GAD65 250-266-specific CD4+ T cells could also be detected by direct ex vivo staining. Analysis of unmanipulated peripheral blood mononuclear cells (PBMCs revealed that GAD65 250-266-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 GAD65 121-140 and GAD65 250-266 epitopes and implicate their possible contribution to the progression of T1D.

  6. Recent gene conversions between duplicated glutamate decarboxylase genes (gadA and gadB) in pathogenic Escherichia coli.

    Bergholz, Teresa M; Tarr, Cheryl L; Christensen, Lisa M; Betting, David J; Whittam, Thomas S

    2007-10-01

    Escherichia coli have evolved adaptive systems to resist strongly acidic habitats in part through the production of 2 biochemically identical isoforms of glutamate decarboxylase (GAD), encoded by the gadA and gadB genes. These genes occur in E. coli and other members of the genospecies (e.g., Shigella spp.) and originated as part of a genomic fitness island acquired early in Escherichia evolution. The present duplicated gad loci are widely spaced on the E. coli chromosome, and the 2 genes are 97% similar in sequence. Comparison of the nucleotide sequences of the gadA and gadB in 16 strains of pathogenic E. coli revealed 3.8% and 5.0% polymorphism in the 2 genes, respectively. Alignment of the homologous genes identified a total of 120 variable sites, including 21 fixed nucleotide differences between the loci within the first 82 codons of the genes. Twenty-three phylogenetically informative sites were polymorphic for the same nucleotides in both genes suggesting recent gene conversions or intergenic recombination. Phylogenetic analysis based on the synonymous substitutions per synonymous site indicated 2 cases in which specific gadA and gadB alleles were more closely related to one another than to other alleles at the corresponding locus. The results indicate that at least 3 gene conversion events have occurred after the gad gene duplication in the evolution of E. coli. Despite multiple gene conversion events, the upstream regulatory regions and the 5' end of each gene remains distinct, suggesting that maintaining functionally different gad genes is important in this acid-resistance mechanism in pathogenic E. coli. PMID:17675652

  7. Hypercapnic ventilatory response in mice lacking the 65 kDa isoform of Glutamic Acid Decarboxylase (GAD65

    Bissonnette John M

    2004-03-01

    Full Text Available Abstract Background Recent reports have shown that there are developmental changes in theventilatory response to hypercapnia in the rat. These are characterizedby an initial large response to carbon dioxide immediately after birthfollowed by a decline with a trough at one week of age, followed by areturn in sensitivity. A second abnormality is seen at postnatal day 5(P5 rats in that they cannot maintain the increase in frequency for 5min of hypercapnia. In mice lacking GAD65 the release of GABA duringsustained synaptic activation is reduced. We hypothesized that thisdevelopmental pattern would be present in the mouse which is also lessmature at birth and that GABA mediates this relative respiratorydepression. Methods In awake C57BL/6J and GAD65-/- mice the ventilatory response to 5%carbon dioxide (CO2 was examined at P2, P4, P6, P7, P12.5, P14.5 andP21.5, using body plethysmography. Results Minute ventilation (VE relative to baseline during hypercapnia from P2through P7 was generally less than from P12.5 onwards, but there was notrough as in the rat. Breaking VE down into its two components showedthat tidal volume remained elevated for the 5 min of exposure to 5% CO2.At P6, but not at other ages, respiratory frequency declined with timeand at 5 min was less that at 2 and 3 min. GAD65-/- animals at P6 showeda sustained increase in respiratory rate for the five mins exposure toCO2. Conclusion These results show, that in contrast to the rat, mice do not show adecline in minute ventilatory response to CO2 at one week of age.Similiar to the rat at P5, mice at P6 are unable to sustain an increasein CO2 induced respiratory frequency and GAD65 contributes to this falloff.

  8. Oral delivery of glutamic acid decarboxylase (GAD)-65 and IL10 by Lactococcus lactis reverses diabetes in recent-onset NOD mice.

    Robert, Sofie; Gysemans, Conny; Takiishi, Tatiana; Korf, Hannelie; Spagnuolo, Isabella; Sebastiani, Guido; Van Huynegem, Karolien; Steidler, Lothar; Caluwaerts, Silvia; Demetter, Pieter; Wasserfall, Clive H; Atkinson, Mark A; Dotta, Francesco; Rottiers, Pieter; Van Belle, Tom L; Mathieu, Chantal

    2014-08-01

    Growing insight into the pathogenesis of type 1 diabetes (T1D) and numerous studies in preclinical models highlight the potential of antigen-specific approaches to restore tolerance efficiently and safely. Oral administration of protein antigens is a preferred method for tolerance induction, but degradation during gastrointestinal passage can impede such protein-based therapies, reducing their efficacy and making them cost-ineffective. To overcome these limitations, we generated a tolerogenic bacterial delivery technology based on live Lactococcus lactis (LL) bacteria for controlled secretion of the T1D autoantigen GAD65370-575 and the anti-inflammatory cytokine interleukin-10 in the gut. In combination with short-course low-dose anti-CD3, this treatment stabilized insulitis, preserved functional β-cell mass, and restored normoglycemia in recent-onset NOD mice, even when hyperglycemia was severe at diagnosis. Combination therapy did not eliminate pathogenic effector T cells, but increased the presence of functional CD4(+)Foxp3(+)CD25(+) regulatory T cells. These preclinical data indicate a great therapeutic potential of orally administered autoantigen-secreting LL for tolerance induction in T1D. PMID:24677716

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

    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

  10. Gender differences in associations of glutamate decarboxylase 1 gene (GAD1 variants with panic disorder.

    Heike Weber

    Full Text Available BACKGROUND: Panic disorder is common (5% prevalence and females are twice as likely to be affected as males. The heritable component of panic disorder is estimated at 48%. Glutamic acid dehydrogenase GAD1, the key enzyme for the synthesis of the inhibitory and anxiolytic neurotransmitter GABA, is supposed to influence various mental disorders, including mood and anxiety disorders. In a recent association study in depression, which is highly comorbid with panic disorder, GAD1 risk allele associations were restricted to females. METHODOLOGY/PRINCIPAL FINDINGS: Nineteen single nucleotide polymorphisms (SNPs tagging the common variation in GAD1 were genotyped in two independent gender and age matched case-control samples (discovery sample n = 478; replication sample n = 584. Thirteen SNPs passed quality control and were examined for gender-specific enrichment of risk alleles associated with panic disorder by using logistic regression including a genotype×gender interaction term. The latter was found to be nominally significant for four SNPs (rs1978340, rs3762555, rs3749034, rs2241165 in the discovery sample; of note, the respective minor/risk alleles were associated with panic disorder only in females. These findings were not confirmed in the replication sample; however, the genotype×gender interaction of rs3749034 remained significant in the combined sample. Furthermore, this polymorphism showed a nominally significant association with the Agoraphobic Cognitions Questionnaire sum score. CONCLUSIONS/SIGNIFICANCE: The present study represents the first systematic evaluation of gender-specific enrichment of risk alleles of the common SNP variation in the panic disorder candidate gene GAD1. Our tentative results provide a possible explanation for the higher susceptibility of females to panic disorder.

  11. Danish children born with glutamic acid decarboxylase-65 and islet antigen-2 autoantibodies at birth had an increased risk to develop type 1 diabetes

    Eising, Stefanie; Nilsson, Anita; Carstensen, Bendix;

    2011-01-01

    A large, population-based case-control cohort was used to test the hypothesis that glutamic acid decarboxylase-65 (GAD65) and islet antigen-2 autoantibodies (IA-2A) at birth predict type 1 diabetes.......A large, population-based case-control cohort was used to test the hypothesis that glutamic acid decarboxylase-65 (GAD65) and islet antigen-2 autoantibodies (IA-2A) at birth predict type 1 diabetes....

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

    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

  13. Gluconic acid production by gad mutant of Klebsiella pneumoniae.

    Wang, Dexin; Wang, Chenhong; Wei, Dong; Shi, Jiping; Kim, Chul Ho; Jiang, Biao; Han, Zengsheng; Hao, Jian

    2016-08-01

    Klebsiella pneumoniae produces many economically important chemicals. Using glucose as a carbon source, the main metabolic product in K. pneumoniae is 2,3-butanediol. Gluconic acid is an intermediate of the glucose oxidation pathway. In the current study, a metabolic engineering strategy was used to develop a gluconic acid-producing K. pneumoniae strain. Deletion of gad, resulting in loss of gluconate dehydrogenase activity, led to the accumulation of gluconic acid in the culture broth. Gluconic acid accumulation by K. pneumoniae Δgad was an acid-dependent aerobic process, with accumulation observed at pH 5.5 or lower, and at higher levels of oxygen supplementation. Under all other conditions tested, 2,3-butanediol was the main metabolic product of the process. In fed batch fermentation, a final concentration of 422 g/L gluconic acid was produced by K. pneumoniae Δgad, and the conversion ratio of glucose to gluconic acid reached 1 g/g. The K. pneumoniae Δgad described in this study is the first genetically modified strain used for gluconic acid production, and this optimized method for gluconic acid production may have important industrial applications. Gluconic acid is an intermediate of this glucose oxidation pathway. Deletion of gad, resulting in loss of gluconate dehydrogenase activity, led to the accumulation of gluconic acid in the culture broth. In fed batch fermentation, a final concentration of 422 g/L gluconic acid was produced by the K. pneumoniae Δgad strain, and the conversion ratio of glucose to gluconic acid reached 1 g/g. PMID:27339313

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

    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

  15. Glutamate acid decarboxylase 1 promotes metastasis of human oral cancer by β-catenin translocation and MMP7 activation

    Glutamate decarboxylase 1 (GAD1), a rate-limiting enzyme in the production of γ-aminobutyric acid (GABA), is found in the GABAergic neurons of the central nervous system. Little is known about the relevance of GAD1 to oral squamous cell carcinoma (OSCC). We investigated the expression status of GAD1 and its functional mechanisms in OSCCs. We evaluated GAD1 mRNA and protein expressions in OSCC-derived cells using real-time quantitative reverse transcriptase-polymerase chain reaction (qRT-PCR) and immunoblotting analyses. To assess the critical functions of GAD1, i.e., cellular proliferation, invasiveness, and migration, OSCC-derived cells were treated with the shRNA and specific GAD1 inhibitor, 3-mercaptopropionic acid (3-MPA). GAD1 expression in 80 patients with primary OSCCs was analyzed and compared to the clinicopathological behaviors of OSCC. qRT-PCR and immunoblotting analyses detected frequent up-regulation of GAD1 in OSCC-derived cells compared to human normal oral keratinocytes. Suppression of nuclear localization of β-catenin and MMP7 secretion was observed in GAD1 knockdown and 3-MPA-treated cells. We also found low cellular invasiveness and migratory abilities in GAD1 knockdown and 3-MPA-treated cells. In the clinical samples, GAD1 expression in the primary OSCCs was significantly (P < 0.05) higher than in normal counterparts and was correlated significantly (P < 0.05) with regional lymph node metastasis. Our data showed that up-regulation of GAD1 was a characteristic event in OSCCs and that GAD1 was correlated with cellular invasiveness and migration by regulating β-catenin translocation and MMP7 activation. GAD1 might play an important role in controlling tumoral invasiveness and metastasis in oral cancer

  16. Glutamic acid decarboxylase antibody-positive paraneoplastic stiff limb syndrome associated with carcinoma of the breast

    Agarwal Pankaj

    2010-01-01

    Full Text Available Stiff limb syndrome (SLS is a rare "focal" variant of stiff person syndrome which presents with rigidity and painful spasms of a distal limb, and abnormal fixed foot or hand postures. Anti-glutamic acid decarboxylase antibodies (GAD-Ab are variably present in most cases. Most reported cases of SLS are unassociated with cancer. We describe a patient with SLS as a paraneoplastic manifestation of breast carcinoma, in whom GAD-Ab was present. The patient responded very well to oral diazepam, baclofen and steroids.This is the third reported case of SLS as a paraneoplastic accompaniment to cancer.

  17. Amino Acid Decarboxylase Activity of Some Lactic Acid Bacteria

    Pelin ERTÜRKMEN; Turhan, İlkay; Öner, Zübeyde

    2015-01-01

    Microorganisms which have decarboxylase activity can form biogenic amine by enzymatic decarboxylation of amino acids in foods. Histamine poisoning results from consumption of foods typically certain types of fish and cheeses that contain unusually high levels of histamine. Therefore, decarboxylase activity is an important problem at the selection of lactic acid bacteria as a starter culture in fermented products. In this study, decarboxylase activities of 161 lactic acid bacteria (LAB) strain...

  18. Cloning and molecular evolution research of porcine GAD65 gene

    YU Hao; SONG Yuefen; LI Li; LIU Di

    2007-01-01

    Glutamate decarboxylase (GAD) has been found in animal and higher plant tissues as well as in yeasts and microorganisms.In animals the enzyme plays an important role in central nervous system activity because the enzyme substrate glutamic acid is a mediator of excitation process and the product, gamma-aminobutyric acid, is the most important mediator of inhibition process in the central nervous system. GAD65 is one form of the glutamate decarboxylases (GAD), GAD65 has been identified as a major autoantigen in type 1 diabetes, so the GAD65 gene of porcine was cloned by RT-PCR method to construct phylogenetic tree, the homology of 13glutamate decarboxylases (GAD) of different origin was analyzed by multiple alignment.

  19. A radiometric microassay for glutamic acid decarboxylase

    A simple method for purifying L-[3H] glutamic acid and incubation conditions suitable for estimating L-glutamic acid decarboxylase activity are described. Routine and recycled cation-exchange procedure for separating γ-aminobutyric acid from L-glutamate are outlined and compared. Recycling increases the sensitivity of the cation-exchange method by 6-7 fold. L-Glutamate decarboxylase activity can be measured reliably in samples of embryonic neural tissue having wet-weights of approximately 1 μg. The cation-exchange method is compared with the anion-exchange and CO2-trapping methods. L-Glutamate decarboxylase activity has been detected in the lumbar spinal cord of the chick embryo at Day 21/4 (stage 14) using the cation-exchange method. This is 5-6 days earlier than L-glutamate decarboxylase activity has been detected in embryonic neural tissue by previous investigators. L-Glutamate decarboxylase is present in the lumbar spinal cord at least as early as the birth of the first lumbar spinal cord neurons and at least 1-2 days before the initiation of synaptogenesis. (author)

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

    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: 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

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

    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

  2. Developmental changes of glutamate acid decarboxylase 67 in mouse brain after hypoxia ischemia

    Fa-Lin XU; Chang-Lian ZHU; Xiao-Yang WANG

    2006-01-01

    Objective To study the developmental changes of glutamic acid decarboxylase-67 ( GAD-67, a GABA synthetic enzyme) in normal and hypoxic ischemic (HI) brain. Methods C57/BL6 mice on postnatal day (P) 5, 9, 21and 60, corresponding developmentally to premature, term, juvenile and adult human brain were investigated by using both Western blot and immunohistochemistry methods either in normal condition or after hypoxic ischemic insult. Results The immunoreactivity of GAD67 was up regulated with brain development and significant difference was seen between mature (P21, P60) and immature (P5, P9) brain. GAD67 immunoreactivity decreased in the ipsilateral hemisphere in all the ages after hypoxia ischemia (HI) insult, but, significant decrease was only seen in the immature brain. Double labeling of GAD67 and cell death marker, TUNEL, in the cortex at 8h post-HI in the P9 mice showed that (15.6 ±7.0)%TUNEL positive cells were GAD67 positive which was higher than that of P60 mice. Conclusion These data suggest that GABAergic neurons in immature brain were more vulnerable to HI insult than that of mature brain.

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

    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

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

    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

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

    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 (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

  6. The role of anti-glutamic acid decarboxylase autoantibodies in mood disorders

    Marco Liguori

    2015-01-01

    Full Text Available Gamma-aminobutyric acid (GABA possibly plays a causative role in mood disorders. This hypothesis originated with studies on the beneficial effect of valproate in mania and as a mood stabilizer. Since valproate is known for its action in increasing the level of GABA, it was indirectly suggested that decreasing levels of GABA were responsible for mood alterations. To identify factors causing the decreased levels of GABA, studies have concentrated on the activity of the enzyme L-glutamic acid decarboxylase (GAD, which catalyzes the transformation of glutamate to GABA, as a decreasing function of this enzyme induces lower levels of the neurotransmitter. Moreover, a very limited amount of research investigated the possible role of glutamic acid decarboxylase antibodies (GADA in determining a decreased enzymatic function of GAD. If these findings are confirmed, it will be possible to improve diagnosis and treatment of mood disorders. In addition, if the presence of GADA is associated with a genetic trait, this would allow and facilitate early diagnoses.

  7. Similar peptides from two beta cell autoantigens, proinsulin and glutamic acid decarboxylase, stimulate T cells of individuals at risk for insulin-dependent diabetes.

    Rudy, G; N. Stone; Harrison, L C; Colman, P. G.; McNair, P; Brusic, V.; French, M. B.; Honeyman, M. C.; Tait, B.; Lew, A M

    1995-01-01

    BACKGROUND: Insulin (1) and glutamic acid decarboxylase (GAD) (2) are both autoantigens in insulin-dependent diabetes mellitus (IDDM), but no molecular mechanism has been proposed for their association. We have identified a 13 amino acid peptide of proinsulin (amino acids 24-36) that bears marked similarity to a peptide of GAD65 (amino acids 506-518) (G. Rudy, unpublished). In order to test the hypothesis that this region of similarity is implicated in the pathogenesis of IDDM, we assayed T c...

  8. Characterization of the Intracellular Glutamate Decarboxylase System: Analysis of Its Function, Transcription, and Role in the Acid Resistance of Various Strains of Listeria monocytogenes

    Karatzas, Kimon-Andreas G.; Suur, Laura; O'Byrne, Conor P.

    2012-01-01

    The glutamate decarboxylase (GAD) system is important for the acid resistance of Listeria monocytogenes. We previously showed that under acidic conditions, glutamate (Glt)/γ-aminobutyrate (GABA) antiport is impaired in minimal media but not in rich ones, like brain heart infusion. Here we demonstrate that this behavior is more complex and it is subject to strain and medium variation. Despite the impaired Glt/GABA antiport, cells accumulate intracellular GABA (GABAi) as a standard response aga...

  9. Association of the −243A>G, +61450C>A Polymorphisms of the Glutamate Decarboxylase 2 (GAD2) Gene with Obesity and Insulin Level in North Indian Population

    PRAKASH, Jai; MITTAL, Balraj; AWASTHI, Shally; SRIVASTAVA, Neena

    2016-01-01

    Background: Obesity associated with type 2 diabetes, and hypertension increased mortality and morbidity. Glutamate decarboxylase 2 (GAD2) gene is associated with obesity and it regulate food intake and insulin level. We investigated the association of GAD-2gene −243A>G (rs2236418) and +61450C>A (rs992990) polymorphisms with obesity and related phenotypes. Methods: Insulin, glucose and lipid levels were estimated using standard protocols. All subjects were genotyped (PCR-RFLP) method. Results: The −243A>G polymorphism of the GAD-2 gene was significantly associated with higher risk of obesity (Pobesity and related phenotype in complex manner, probably by regulating the food intake, insulin and body weight.

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

    ... features of aromatic L-amino acid decarboxylase deficiency. Neurology. 2010 Jul 6;75(1):64-71. doi: ... WNL.0b013e3181e620ae. Epub 2010 May 26. Erratum in: Neurology. 2010 Aug 10;75(6):576. Dosage error ...

  11. Decoding genome-wide GadEWX-transcriptional regulatory networks reveals multifaceted cellular responses to acid stress in Escherichia coli

    Seo, Sang Woo; Kim, Donghyuk; O'Brien, Edward J.;

    2015-01-01

    . We demonstrate that GadEWX directly and coherently regulate several proton-generating/consuming enzymes with pairs of negative-feedback loops for pH homeostasis. In addition, GadEWX regulate genes with assorted functions, including molecular chaperones, acid resistance, stress response and other...... comprehensively reconstruct the genome-wide GadEWX transcriptional regulatory network and RpoS involvement in E. coli K-12 MG1655 under acidic stress. Integrative data analysis reveals that GadEWX regulons consist of 45 genes in 31 transcription units and 28 of these genes were associated with RpoS-binding sites...... regulatory activities. These results show how GadEWX simultaneously coordinate many cellular processes to produce the overall response of E. coli to acid stress....

  12. A systematic review on aromatic L-amino acid decarboxylase (5-hydroxytryptophan decarboxylase)

    Aromatic L-amino acid decarboxylase (AADC, EC. 4.1.1.28) with L-5-hydroxytryptophan as a substrate (also called L-5-hydroxytryptophan decarboxylase, 5-HTPDC) decarboxylates L-5-hydroxytryptophan to serotonin (5-HT), an important neurotransmitter that involved in the regulation of neuronal functions, behaviour and emotion of higher animals. As it is an important enzyme, many researchers are now working on its physiological functions and properties and also on its isolation, purification and characterization from mammalian tissues. But up to now no systematic review studies have been done on this enzyme. We made systematic studies on this enzyme in tissues and brains of rats, and human subjects. We also developed highly sensitive assay methods of the enzyme. This new method led us to discover the enzyme in the sera of various animals. We examined the developmental changes of 5-HTPDC in the sera of animals. We discovered an endogenous inhibitor of the enzyme in the monkey blood. The purification of the enzyme were performed by us and other researches from the sera, brains, adrenals, liver and kidneys of mammals. These and other results of up to date research papers on 5-HTPDC have been reviewed in this paper. (author). 71 refs, 10 figs, 14 tabs

  13. Stereochemical course of rat liver cysteinesulfinic acid decarboxylase

    Rat liver homogenate, exhibiting very high cysteinesulfinic acid (CSA) decarboxylase activity, was used to decarboxylate [2-2H1]-L-CSA to [2-2H1]-hypotaurine (HT)2. The latter was desulfurized with Raney nickel to [1-2H1]-ethylamine. A 2H NMR spectrum of the (-)camphanamide derivative of the latter revealed the labeling stereochemistry. Similarly, unlabeled CSA was decarboxylated by rat liver homogenate in a D2O containing medium, and the product HT similarly desulfurized and derivatized. The reactions were followed by use of a new HPLC-based assay for CSA decarboxylase which allows simultaneous measurement of glutamate decarboxylation (which was negligible with rat liver homogenates). The results show that the decarboxylation proceeds with retention of configuration

  14. Purification and Characterization of Gallic Acid Decarboxylase from Pantoea agglomerans T71

    Zeida, Mitsuhiro; Wieser, Marco; Yoshida, Toyokazu; Sugio, Tsuyoshi; Nagasawa, Toru

    1998-01-01

    Oxygen-sensitive gallic acid decarboxylase from Pantoea (formerly Enterobacter) agglomerans T71 was purified from a cell extract after stabilization by reducing agents. This enzyme has a molecular mass of approximately 320 kDa and consists of six identical subunits. It is highly specific for gallic acid. Gallic acid decarboxylase is unique among similar decarboxylases in that it requires iron as a cofactor, as shown by plasma emission spectroscopy (which revealed an iron content of 0.8 mol pe...

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

    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

  16. Tolerogenic dendritic cells induce antigen-specific hyporesponsiveness in insulin- and glutamic acid decarboxylase 65-autoreactive T lymphocytes from type 1 diabetic patients.

    Segovia-Gamboa, Norma; Rodríguez-Arellano, Martha Eunice; Rangel-Cruz, Rafael; Sánchez-Díaz, Moisés; Ramírez-Reyes, Julio César; Faradji, Raquel; González-Domínguez, Érika; Sánchez-Torres, Carmen

    2014-09-01

    Tolerogenic dendritic cells (tDC) constitute a promising therapy for autoimmune diseases, since they can anergize T lymphocytes recognizing self-antigens. Patients with type 1 diabetes mellitus (T1D) have autoreactive T cells against pancreatic islet antigens (insulin, glutamic acid decarboxylase 65 -GAD65-). We aimed to determine the ability of tDC derived from T1D patients to inactivate their insulin- and GAD65-reactive T cells. CD14+ monocytes and CD4+CD45RA- effector/memory lymphocytes were isolated from 25 patients. Monocyte-derived DC were generated in the absence (control, cDC) or presence of IL-10 and TGF-β1 (tDC), and loaded with insulin or GAD65. DC were cultured with T lymphocytes (primary culture), and cell proliferation and cytokine secretion were determined. These lymphocytes were rechallenged with insulin-, GAD65- or candidin-pulsed cDC (secondary culture) to assess whether tDC rendered T cells hyporesponsive to further stimulation. In the primary cultures, tDC induced significant lower lymphocyte proliferation and IL-2 and IFN-γ secretion than cDC; in contrast, tDC induced higher IL-10 production. Lymphocytes from 60% of patients proliferated specifically against insulin or GAD65 (group 1), whereas 40% did not (group 2). Most patients from group 1 had controlled glycemia. The secondary cultures showed tolerance induction to insulin or GAD65 in 14 and 10 patients, respectively. A high percentage of these patients (70-80%) belonged to group 1. Importantly, tDC induced antigen-specific T-cell hyporesponsiveness, since the responses against unrelated antigens were unaffected. These results suggest that tDC therapy against multiple antigens might be useful in a subset of T1D patients. PMID:24993292

  17. Compartmentalization of GABA synthesis by GAD67 differs between pancreatic beta cells and neurons

    Kanaani, Jamil; Cianciaruso, Chiara; Phelps, Edward A; Pasquier, Miriella; Brioudes, Estelle; Baekkeskov, Steinunn; Billestrup, Nils

    2015-01-01

    The inhibitory neurotransmitter GABA is synthesized by the enzyme glutamic acid decarboxylase (GAD) in neurons and in pancreatic β-cells in islets of Langerhans where it functions as a paracrine and autocrine signaling molecule regulating the function of islet endocrine cells. The localization of...

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

    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...

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

    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 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

  20. Evolution and expression analysis of the soybean glutamate decarboxylase gene family

    Tae Kyung Hyun; Seung Hee Eom; Xiao Han; Ju-Sung Kim

    2014-12-01

    Glutamate decarboxylase (GAD) is an enzyme that catalyses the conversion of L-glutamate into -aminobutyric acid (GABA), which is a four-carbon non-protein amino acid present in all organisms. Although plant GAD plays important roles in GABA biosynthesis, our knowledge concerning GAD gene family members and their evolutionary relationship remains limited. Therefore, in this study, we have analysed the evolutionary mechanisms of soybean GAD genes and suggested that these genes expanded in the soybean genome partly due to segmental duplication events. The approximate dates of duplication events were calculated using the synonymous substitution rate, and we suggested that the segmental duplication of GAD genes in soybean originated 9.47 to 11.84 million years ago (Mya). In addition, all segmental duplication pairs (GmGAD1/3 and GmGAD2/4) are subject to purifying selection. Furthermore, GmGAD genes displayed differential expression either in their transcript abundance or in their expression patterns under abiotic stress conditions like salt, drought, and cold. The expression pattern of paralogous pairs suggested that they might have undergone neofunctionalization during the subsequent evolution process. Taken together, our results provide valuable information for the evolution of the GAD gene family and represent the basis for future research on the functional characterization of GAD genes in higher plants.

  1. Glutamic acid decarboxylase autoantibody-positivity post-partum is associated with impaired β-cell function in women with gestational diabetes mellitus

    Lundberg, T. P.; Højlund, K.; Snogdal, L. S.;

    2015-01-01

    AIMS: To investigate whether the presence of glutamic acid decarboxylase (GAD) autoantibodies post-partum in women with prior gestational diabetes mellitus was associated with changes in metabolic characteristics, including β-cell function and insulin sensitivity. METHODS: During 1997-2010, 407...... women with gestational diabetes mellitus were offered a 3-month post-partum follow-up including anthropometrics, serum lipid profile, HbA1c and GAD autoantibodies, as well as a 2-h oral glucose tolerance test (OGTT) with blood glucose, serum insulin and C-peptide at 0, 30 and 120 min. Indices of insulin...... similar age and prevalence of diabetes mellitus. Women who were GAD+ve had significantly higher 2-h OGTT glucose concentrations during their index-pregnancy (10.5 vs. 9.8 mmol/l, P = 0.001), higher fasting glucose (5.2 vs. 5.0 mmol/l, P = 0.02) and higher 2-h glucose (7.8 vs. 7.1 mmol/l, P = 0.05) post...

  2. Detection of GAD-Ab index in diabetic patients using 35S labeled recombinant human GAD65 antigen

    Objective: To establish a novel method for measuring glutamic acid decarboxylase autoanti-bodies(GAD-Ab). Methods: Recombinant human GAD65 was used as the antigen, in vitro transcribed and translated 35S-GAD65 as the tracer, a self-designed rotating incubation apparatus as the incubator, protein-A sepharose as the precipitator, and the liquid scintillation counter was used to measure radioactive count value to detect GAD-Ab. The positive cut-off point of GAD-Ab index was determined as > 0.05 by the 99.5% percentile in 109 healthy individuals. GAD-Ab levels were determined in 43 type 1 and 226 type 2 diabetic patients. Results: The optimized working conditions included SJ1515 35S-methionine for in vitro transcription and translation, 20-30 r/min setup of rotating incubation apparatus, test temperature 4-25 degree C, freshly prepared buffer of pH 7.2-7.4, and horizontal rotor centrifuge. The new method was better than original one, with intra-assay CV of 4.9%-8.3% and inter-assay CV of 7.1%-10.8 %, specificity of 98.2%. The results were comparable with the figures issued by an international standardized laboratory (concordance was 98.3%, Kappa value 0.971). The positive rate of GAD-Ab was 58.1% (25 of 43) in type 1 and 10.2%(23 of 226) in type 2 diabetes patients, but only 1.8% (2 of 109) in healthy individuals. Conclusion: The new assay for GAD-Ab is a highly sensitive, accurate, specific and reproducible method for clinical use

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

    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

  4. Stiff-person syndrome (SPS) and anti-GAD-related CNS degenerations: protean additions to the autoimmune central neuropathies.

    Ali, Fatima; Rowley, Merrill; Jayakrishnan, Bindu; Teuber, Suzanne; Gershwin, M Eric; Mackay, Ian R

    2011-09-01

    Stiff Person Syndrome (SPS) is a rare autoimmune neurological disease attributable to autoantibodies to glutamic acid decarboxylase (anti-GAD) more usually associated with the islet beta cell destruction of autoimmune type 1 diabetes (T1D). SPS is characterized by interference in neurons with the synthesis/activity of the inhibitory neurotransmitter gamma amino butyric acid (GABA) resulting in the prototypic progressive spasmodic muscular rigidity of SPS, or diverse neurological syndromes, cerebellar ataxia, intractable epilepsy, myoclonus and several others. Remarkably, a single autoantibody, anti-GAD, can be common to widely different disease expressions, i.e. T1D and SPS. One explanation for these data is the differences in epitope engagement between the anti-GAD reactivity in SPS and T1D: in both diseases, anti-GAD antibody reactivity is predominantly to a conformational epitope region in the PLP- and C-terminal domains of the 65 kDa isoform but, additionally in SPS, there is reactivity to conformational epitope(s) on GAD67, and short linear epitopes in the C-terminal region and at the N-terminus of GAD65. Another explanation for disease expressions in SPS includes ready access of anti-GAD to antigen sites due to immune responsiveness within the CNS itself according to intrathecal anti-GAD-specific B cells and autoantibody. Closer study of the mysterious stiff-person syndrome should enhance the understanding of this disease itself, and autoimmunity in general. PMID:21680149

  5. AUTOANTIBODIES TO GLUTAMIC ACID DECARBOXYLASE AS A PATHOGENETIC MARKER OF TYPE I DIABETES MELLITUS

    N. V. Piven

    2014-07-01

    Full Text Available Abstract. A new method of enzyme-linked immunosorbent assay (in solid-phase ELISA format has been developed to determine concentrations of autoantibodies to glutamic acid decarboxylase, as well as an evidencebased methodology is proposed for its medical implications, as a quantitative pathogenetic predictive marker of autoimmune diagnostics in type 1 diabetes mellitus. This technique could be implied for serial production of diagnostic reagent kits, aimed for detection of autoantibodies to glutamic acid decarboxylase by means of ELISA approach. (Med. Immunol., 2011, vol. 13, N 2-3, pp 257-260

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

    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

  7. Miller-Fisher Syndrome: Are Anti-GAD Antibodies Implicated in Its Pathophysiology?

    Ioannis E. Dagklis

    2016-01-01

    Full Text Available Miller-Fisher syndrome (MFS is considered as a variant of the Guillain-Barre syndrome (GBS and its characteristic clinical features are ophthalmoplegia, ataxia, and areflexia. Typically, it is associated with anti-GQ1b antibodies; however, a significant percentage (>10% of these patients are seronegative. Here, we report a 67-year-old female patient who presented with the typical clinical features of MFS. Workup revealed antibodies against glutamic acid decarboxylase (GAD in relatively high titers while GQ1b antibodies were negative. Neurological improvement was observed after intravenous gamma globulin and follow-up examinations showed a continuous clinical amelioration with simultaneous decline of anti-GAD levels which finally returned to normal values. This case indicates that anti-GAD antibodies may be associated with a broader clinical spectrum and future studies in GQ1b-seronegative patients could determine ultimately their clinical and pathogenetic significance in this syndrome.

  8. Miller-Fisher Syndrome: Are Anti-GAD Antibodies Implicated in Its Pathophysiology?

    Papagiannopoulos, Sotirios; Theodoridou, Varvara; Argyropoulou, Ourania; Bostantjopoulou, Sevasti

    2016-01-01

    Miller-Fisher syndrome (MFS) is considered as a variant of the Guillain-Barre syndrome (GBS) and its characteristic clinical features are ophthalmoplegia, ataxia, and areflexia. Typically, it is associated with anti-GQ1b antibodies; however, a significant percentage (>10%) of these patients are seronegative. Here, we report a 67-year-old female patient who presented with the typical clinical features of MFS. Workup revealed antibodies against glutamic acid decarboxylase (GAD) in relatively high titers while GQ1b antibodies were negative. Neurological improvement was observed after intravenous gamma globulin and follow-up examinations showed a continuous clinical amelioration with simultaneous decline of anti-GAD levels which finally returned to normal values. This case indicates that anti-GAD antibodies may be associated with a broader clinical spectrum and future studies in GQ1b-seronegative patients could determine ultimately their clinical and pathogenetic significance in this syndrome. PMID:27239355

  9. Differential expression of glutamic acid decarboxylase in rat and human islets

    Petersen, J S; Russel, S; Marshall, M O;

    1993-01-01

    The GABA synthesizing enzyme GAD is a prominent islet cell autoantigen in type I diabetes. The two forms of GAD (GAD64 and GAD67) are encoded by different genes in both rats and humans. By in situ hybridization analysis of rat and human pancreases, expression of both genes was detected in rat isl...

  10. Detection of GAD65 antibodies in diabetes and other autoimmune diseases using a simple radioligand assay.

    Petersen, J S; Hejnaes, K R; Moody, A; Karlsen, A E; Marshall, M O; Høier-Madsen, M; Boel, E; Michelsen, B K; Dyrberg, T

    1994-03-01

    Autoantibodies to glutamic acid decarboxylase (GAD) are frequent at or before the onset of insulin-dependent diabetes mellitus (IDDM). We have developed a simple, reproducible, and quantitative immunoprecipitation radioligand assay using as antigen in vitro transcribed and translated [35S]methionine-labeled human islet GAD65. By using this assay, 77% (77 of 100) of serum samples from recent-onset IDDM patients were positive for GAD65 antibodies compared with 4% (4 of 100) of serum samples from healthy control subjects. In competition analysis with unlabeled purified recombinant human islet GAD65, binding to tracer was inhibited in 74% (74 of 100) of the GAD65-positive IDDM serum samples compared with 2% of the control samples. The levels of GAD antibodies expressed as an index value relative to a standard serum, analyzed with or without competition, were almost identical (r = 0.991). The intra- and interassay variations of a positive control serum sample were 2.9 and 7.6%, respectively (n = 4). The frequency of GAD antibodies was significantly higher with IDDM onset before the age of 30 (80%, 59 of 74) than after the age of 30 (48%, 10 of 21) (P DNA autoantibodies (8% [2 of 25] and 4% [1 of 25] in competition analysis) or rheuma factor autoantibodies [12% (4 of 35) and 3% (1 of 35) in competition analysis] was not different from that in control samples. In contrast, in sera positive for ribonucleoprotein antibodies the frequency of GAD antibodies was significantly increased (73% [51 of 70] and 10% [7 of 70] in competition analysis [P history of IDDM for the presence of this marker. PMID:8314020

  11. The spatiotemporal segregation of GAD forms defines distinct GABA signaling functions in the developing mouse olfactory system and provides novel insights into the origin and migration of GnRH neurons.

    Vastagh, Csaba; Schwirtlich, Marija; Kwakowsky, Andrea; Erdélyi, Ferenc; Margolis, Frank L; Yanagawa, Yuchio; Katarova, Zoya; Szabó, Gábor

    2015-03-01

    Gamma-aminobutyric acid (GABA) has a dual role as an inhibitory neurotransmitter in the adult central nervous system (CNS) and as a signaling molecule exerting largely excitatory actions during development. The rate-limiting step of GABA synthesis is catalyzed by two glutamic acid decarboxylase isoforms GAD65 and GAD67 coexpressed in the GABAergic neurons of the CNS. Here we report that the two GADs show virtually nonoverlapping expression patterns consistent with distinct roles in the developing peripheral olfactory system. GAD65 is expressed exclusively in undifferentiated neuronal progenitors confined to the proliferative zones of the sensory vomeronasal and olfactory epithelia In contrast GAD67 is expressed in a subregion of the nonsensory epithelium/vomeronasal organ epithelium containing the putative Gonadotropin-releasing hormone (GnRH) progenitors and GnRH neurons migrating from this region through the frontonasal mesenchyme into the basal forebrain. Only GAD67+, but not GAD65+ cells accumulate detectable GABA. We further demonstrate that GAD67 and its embryonic splice variant embryonic GAD (EGAD) concomitant with GnRH are dynamically regulated during GnRH neuronal migration in vivo and in two immortalized cell lines representing migratory (GN11) and postmigratory (GT1-7) stage GnRH neurons, respectively. Analysis of GAD65/67 single and double knock-out embryos revealed that the two GADs play complementary (inhibitory) roles in GnRH migration ultimately modulating the speed and/or direction of GnRH migration. Our results also suggest that GAD65 and GAD67/EGAD characterized by distinct subcellular localization and kinetics have disparate functions during olfactory system development mediating proliferative and migratory responses putatively through specific subcellular GABA pools. PMID:25125027

  12. ELISA Test for Analyzing of Incidence of Type 1 Diabetes Autoantibodies (GAD and IA2) in Children and Adolescents

    Delic-Sarac, Marina; Mutevelic, Selma; Karamehic, Jasenko; Subasic, Djemo; Jukic, Tomislav; Coric, Jozo; Ridjic, Ognjen; Panjeta, Mirsad; Zunic, Lejla

    2016-01-01

    Introduction: Anti GAD (antibodies on glutamic acid decarboxylase) and anti-IA2 antibodies (against tyrosine phosphatase), today, have their place and importance in diagnosis and prognosis of Type 1 diabetes. Huge number of patients with diabetes mellitus type 1 have these antibodies. Insulin antibodies are of critical importance in diagnosis of diabetes mellitus type 1 for pediatric population. Materials and methods: During 2014, the samples of 80 patients from Clinical Center University Sarajevo (CCUS) Pediatrics clinic’s, Endocrinology department were analyzed on anti-GAD and IA2 antibodies. The samples of serums of all patients were analyzed with ELISA tests using Anti GAD ELISA (IgG) kites from EUROIMMUN company. These are quantitative in vitro tests for human antibodies against decarboxylase of glutamine acid (GAD) and IA2, in serum or EDTA plasm. Results: During the period of one year, in CCUS’s Organizational unit, Institute for Clinical Immunology, 80 samples of patients with anti GAD and IA2 antibodies were analyzed. Out of total number of samples, 41 were male patients, or 51% and 39 female, or 49%. The youngest patient was born in 2012, and the oldest in 1993. Age average was represented by the patients born in 2001. Share of positive results for IA2 antibodies and GAD antibodies was 37% for IA2 antibodies, and 63% for GAD antibodies. Discussion: During an autoimmune – mediated Diabetes mellitus type 1 leads to T-cell mediated destruction of beta cells of pancreatic islets, reduced production of insulin and glucose metabolism. Studies have shown that these bodies are the most intense single marker for identifying persons with increased risk for diabetes development. PMID:27041813

  13. VGluT1- and GAD-immunoreactive terminals in synaptic contact with PAG-immunopositive neurons in principal sensory trigeminal nucleus of rat

    Yu-lin DONG; Fu-xing ZHANG; You-wang PANG; Jin-lian LI

    2007-01-01

    Aim: To trace the origin of abundant vesicular glutamate transporter 1-like immu-noreactive (VGIuT1-LI) axon terminals in the dorsal division of the principal sensory trigeminal nucleus (Vpd) and the relationships between VGIuT1-LI, as well as the glutamic acid decarboxylase (GAD)-LI axon terminals, and phosphate-activated glutaminase (PAG)-LI thalamic projecting neurons in the Vpd. Methods: Following unilateral trigeminal rhizotomy, triple-immunofluorescence histoche-mistry for VGluT1, GAD and PAG and the immunogold-silver method for VGIuT1or GAD, combined with the immunoperoxidase method for PAG were performed, respectively. Results: After unilateral trigeminal rhizotomy, the density of VGluT1-like immunoreactivity (IR) in the Vpd on the lesion side was reduced compared to its contralateral counterpart. Under the confocal laser-scanning microscope, theVGIuT1-LI or GAD-LI axon terminals were observed to be in close apposition to the PAG-LI thalamic projecting neuronal profiles, and further electron microscope immunocytochemistry confirmed that VGluT1- and GAD-LI axon terminals made asymmetrical and symmetrical synapses upon the PAG-LI neuronal structures. Conclusion: The present results suggest that the VGluT1-LI axon terminals, which mainly arise from the primary afferents of the trigeminal ganglion, along with the PAG-LI neuronal profiles, form the key synaptic connection involved in sensory signaling.

  14. Phenolic Acid-Mediated Regulation of the padC Gene, Encoding the Phenolic Acid Decarboxylase of Bacillus subtilis▿ †

    Tran, Ngoc Phuong; Gury, Jerôme; Dartois, Véronique; Nguyen, Thi Kim Chi; Seraut, Hélène; Barthelmebs, Lise; Gervais, Patrick; Cavin, Jean-François

    2008-01-01

    In Bacillus subtilis, several phenolic acids specifically induce expression of padC, encoding a phenolic acid decarboxylase that converts these antimicrobial compounds into vinyl derivatives. padC forms an operon with a putative coding sequence of unknown function, yveFG, and this coding sequence does not appear to be involved in the phenolic acid stress response (PASR). To identify putative regulators involved in the PASR, random transposon mutagenesis, combined with two different screens, w...

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

    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

  16. Enhanced expression of glutamate decarboxylase 65 improves symptoms of rat parkinsonian models.

    Lee, B; Lee, H; Nam, Y R; Oh, J H; Cho, Y H; Chang, J W

    2005-08-01

    In this study, we report the amelioration of parkinsonian symptoms in rat Parkinson's disease (PD) models, as a result of the expression of glutamate decarboxylase (GAD) 65 with a modified cytomegalovirus (CMV) promoter. The transfer of the gene for gamma-amino butryic acid (GAD), the rate-limiting enzyme in gama-amino butrylic acid (GABA) production, has been investigated as a means to increase inhibitory synaptic activity. Electrophysiological evidence suggests that the transfer of the GAD65 gene to the subthalamic nucleus (STN) can change the excitatory output of this nucleus to inhibitory output. Our in vitro results also demonstrated higher GAD65 expression in cells transfected with the JDK promoter, as compared to cells transfected with the CMV promoter. Also, a rat PD model in which recombinant adeno-associated virus-2 (rAAV2)-JDK-GAD65 was delivered into the STN exhibited significant behavioral improvements, as compared to the saline-injected group. Interestingly, we observed that these behavioral improvements were more obvious in rat PD models in which rAAV2-JDK-GAD65 was injected into the STN than in rat PD models in which rAAV2-CMV-GAD65 was injected into the STN. Moreover, according to electrophysiological data, the rAAV2-JDK-GAD65-injected group exhibited more constant improvements in firing rates than did the rAAV2-CMV-GAD65-injected group. These data indicate that the JDK promoter, when coupled with GAD65 expression, is more effective with regard to parkinsonian symptoms than is the CMV promoter. PMID:15829994

  17. Glutamic acid decarboxylase antibodies are indicators of the course, but not of the onset, of diabetes in middle-aged adults: the Atherosclerosis Risk in Communities Study

    A. Vigo

    2007-07-01

    Full Text Available To efficiently examine the association of glutamic acid decarboxylase antibody (GADA positivity with the onset and progression of diabetes in middle-aged adults, we performed a case-cohort study representing the ~9-year experience of 10,275 Atherosclerosis Risk in Communities Study participants, initially aged 45-64 years. Antibodies to glutamic acid decarboxylase (GAD65 were measured by radioimmunoassay in 580 incident diabetes cases and 544 non-cases. The overall weighted prevalence of GADA positivity (³1 U/mL was 7.3%. Baseline risk factors, with the exception of smoking and interleukin-6 (P £ 0.02, were generally similar between GADA-positive and -negative individuals. GADA positivity did not predict incident diabetes in multiply adjusted (HR = 1.04; 95%CI = 0.55, 1.96 proportional hazard analyses. However, a small non-significant adjusted risk (HR = 1.29; 95%CI = 0.58, 2.88 was seen for those in the highest tertile (³2.38 U/mL of positivity. GADA-positive and GADA-negative non-diabetic individuals had similar risk profiles for diabetes, with central obesity and elevated inflammation markers, aside from glucose, being the main predictors. Among diabetes cases at study's end, progression to insulin treatment increased monotonically as a function of baseline GADA level. Overall, being GADA positive increased risk of progression to insulin use almost 10 times (HR = 9.9; 95%CI = 3.4, 28.5. In conclusion, in initially non-diabetic middle-aged adults, GADA positivity did not increase diabetes risk, and the overall baseline profile of risk factors was similar for positive and negative individuals. Among middle-aged adults, with the possible exception of those with the highest GADA levels, autoimmune pathophysiology reflected by GADA may become clinically relevant only after diabetes onset.

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

    The crystal structure of phenolic acid decarboxylase from B. pumilus strain UI-670 has been determined and refined at 1.69 Å resolution. The enzyme is a dimer, with each subunit adopting a β-barrel structure belonging to the lipocalin fold. 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

  19. 2-ketogluconic acid secretion by incorporation of Pseudomonas putida KT 2440 gluconate dehydrogenase (gad) operon in Enterobacter asburiae PSI3 improves mineral phosphate solubilization.

    Kumar, Chanchal; Yadav, Kavita; Archana, G; Naresh Kumar, G

    2013-09-01

    Enterobacter asburiae PSI3 is known to efficiently solubilize rock phosphate by secretion of approximately 50 mM gluconic acid in Tris-buffered medium in the presence of 75 mM glucose and in a mixture of seven aldosugars each at 15 mM concentration, mimicking alkaline vertisol soils. Efficacy of this bacterium in the rhizosphere requires P release in the presence of low amount of sugars. To achieve this, E. asburiae PSI3 has been manipulated to express gluconate dehydrogenase (gad) operon of Pseudomonas putida KT 2440 to produce 2-ketogluconic acid. E. asburiae PSI3 harboring gad operon had 438 U of GAD activity, secreted 11.63 mM 2-ketogluconic and 21.65 mM gluconic acids in Tris-rock phosphate-buffered medium containing 45 mM glucose. E. asburiae PSI3 gad transformant solubilized 0.84 mM P from rock phosphate in TRP-buffered liquid medium. In the presence of a mixture of seven sugars each at 12 mM, the transformant brought about a drop in pH to 4.1 and released 0.53 mM P. PMID:23666029

  20. Cellular target recognition of perfluoroalkyl acids: In vitro evaluation of inhibitory effects on lysine decarboxylase

    Wang, Sufang; Lv, Qiyan; Yang, Yu, E-mail: yuyang@rcees.ac.cn; Guo, Liang-Hong, E-mail: LHGuo@rcees.ac.cn; Wan, Bin; Zhao, Lixia

    2014-10-15

    Perfluoroalkyl acids (PFAAs) have been shown to bind with hepatic peroxisome proliferator receptor α, estrogen receptors and human serum albumin and subsequently cause some toxic effects. Lysine decarboxylase (LDC) plays an important role in cell growth and developmental processes. In this study, the inhibitory effect of 16 PFAAs, including 13 perfluorinated carboxylic acids (PFCAs) and 3 perfluorinated sulfonic acids (PFSAs), on lysine decarboxylase (LDC) activity was investigated. The inhibition constants obtained in fluorescence enzyme assays fall in the range of 2.960 μM to 290.8 μM for targeted PFCAs, and 41.22 μM to 67.44 μM for targeted PFSAs. The inhibitory effect of PFCAs increased significantly with carbon chain (7–18 carbons), whereas the short chain PFCAs (less than 7 carbons) did not show any effect. Circular dichroism results showed that PFAA binding induced significant protein secondary structural changes. Molecular docking revealed that the inhibitory effect could be rationalized well by the cleft binding mode as well as the size, substituent group and hydrophobic characteristics of the PFAAs. At non-cytotoxic concentrations, three selected PFAAs inhibited LDC activity in HepG2 cells, and subsequently resulted in the decreased cadaverine level in the exposed cells, suggesting that LDC may be a possible target of PFAAs for their in vivo toxic effects. - Highlights: • Inhibitory effects of PFAAs on lysine decarboxylase activity were evaluated. • Four different methods were employed to investigate the mechanisms. • The long chain PFAAs showed inhibitory effect compare with 4–6 carbon chain. • The long chain PFAAs bound with LDC differently from the short ones. • The results in cells correlate with those obtained from fluorescence assay.

  1. Cellular target recognition of perfluoroalkyl acids: In vitro evaluation of inhibitory effects on lysine decarboxylase

    Perfluoroalkyl acids (PFAAs) have been shown to bind with hepatic peroxisome proliferator receptor α, estrogen receptors and human serum albumin and subsequently cause some toxic effects. Lysine decarboxylase (LDC) plays an important role in cell growth and developmental processes. In this study, the inhibitory effect of 16 PFAAs, including 13 perfluorinated carboxylic acids (PFCAs) and 3 perfluorinated sulfonic acids (PFSAs), on lysine decarboxylase (LDC) activity was investigated. The inhibition constants obtained in fluorescence enzyme assays fall in the range of 2.960 μM to 290.8 μM for targeted PFCAs, and 41.22 μM to 67.44 μM for targeted PFSAs. The inhibitory effect of PFCAs increased significantly with carbon chain (7–18 carbons), whereas the short chain PFCAs (less than 7 carbons) did not show any effect. Circular dichroism results showed that PFAA binding induced significant protein secondary structural changes. Molecular docking revealed that the inhibitory effect could be rationalized well by the cleft binding mode as well as the size, substituent group and hydrophobic characteristics of the PFAAs. At non-cytotoxic concentrations, three selected PFAAs inhibited LDC activity in HepG2 cells, and subsequently resulted in the decreased cadaverine level in the exposed cells, suggesting that LDC may be a possible target of PFAAs for their in vivo toxic effects. - Highlights: • Inhibitory effects of PFAAs on lysine decarboxylase activity were evaluated. • Four different methods were employed to investigate the mechanisms. • The long chain PFAAs showed inhibitory effect compare with 4–6 carbon chain. • The long chain PFAAs bound with LDC differently from the short ones. • The results in cells correlate with those obtained from fluorescence assay

  2. 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.

    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

  3. 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 ▿

    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

  4. Aromatic L-Amino acid decarboxylase deficiency: A new case from Turkey with a novel mutation

    Kivilcim Gucuyener

    2014-01-01

    Full Text Available Aromatic L-amino acid decarboxylase (AADC, a vitamin B6-requiring enzyme that converts L-dopa to dopamine and 5-hydroxytryptophan to serotonin. Deficiency of this enzyme results in developmental delay, muscular hypotonia, dystonia, involuntary movements, autonomic dysfunction, and oculogyric crises. We now report a 2-year-old Turkish boy with AADC deficiency confirmed by greatly reduced AADC activity in the plasma and by genetic studies. Mutation analysis revealed a homozygous mutation c.208C > T (p. His70Tyr in exon 3 of the AADC gene which has not been described to date.

  5. Identification and molecular cloning of glutamate decarboxylase gene from Lactobacillus casei

    Yasaman Tavakoli

    2015-09-01

    Full Text Available Gamma-amino butyric acid (GABA possesses several physiological functions such as neurotransmission, induction of hypotension, diuretic and tranquilizer effects. Production of GABA-enriched products by lactic acid bacteria has been a focus of different researches in recent years because of their safety and health-promoting specifities. In this study, glutamate decarboxylase (gad gene of a local strains Lactobacillus casei was identified and cloned. In order to clone the gad gene from this strain, the PCR was carried out using primers designed based on conserved regions. The PCR product was purified and ligated into PGEM-T vector. Comparison of obtained sequences shows that this fragment codes the pyridoxal 5′-phosphate binding region. This strain could possibly be used for the industrial GABA production and also for development of functional fermented foods. Gad gene manipulation can also either decrease or increase the activity of enzyme in bacteria.

  6. Enhancing Muconic Acid Production from Glucose and Lignin-Derived Aromatic Compounds via Increased Protocatechuate Decarboxylase Activity

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

    2016-12-01

    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 PCA 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. 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.

  7. 谷氨酸脱羧酶抗体微量平板放射结合检测法的建立与初步应用%Micro-plate radiobinding assay of autoantibody to glutamic acid decarboxylase

    黄干; 金河来; 王霞; 李卉; 张松; 周智广

    2008-01-01

    Objective The purpose of this study was to develop a high-throughput micro-plate radiobinding assay (RBA) of glutamic acid decarboxylase antibody (GAD-Ab) and to evaluate its clinical application. Methods 35labeled GAD65 antigen was incubated with sera for 24 h on a 96-well plate, and then transferred to the Millipore plate coated with protein A, which was washed with 4℃ PBS buffer, and then counted by a liquid scintillation counter. The GAD-Ab results were expressed by WHO standard unit (U/ml). A total of 224 healthy controls, 162 patients with type 1 diabetes mellitus(T1DM) and 210 patients with newly diagnosed type 2 diabetes (T2DM) were recruited. A total of 119 TI DM and healthy cases with gradually changing GAD-Ab levels were selected to compare the consistency of micro-plate RBA with conventional radioligand assay (RLA). Blood samples were obtained from the peripheral vein and finger tip in 32 healthy controls, 35 T1DM and 24 T2DM patients, and tested with micro-plate RBA and then compared with the conventional RLA to investigate the reliability of finger tip sampling. Linear correlation,student's t-test, variance analysis and receiver operating characteristic (ROC) curve were performed using SPSS 11.5. Results (1) The optimized conditions of micro-plate RBA included 2 μl serum incubated with3 ×104 counts/min 35S-GAD for 24 h under slow vibration, antigen-antibody compounds washed 10 times by 4℃ PBS buffer, and radioactivity counted with Optiphase Supermix scintillation liquid. (2)The intra-batch CV of the micro-plate RBA was 3.8%- 10.2%, and the inter-batch CV was 5.6%- 11.9%. The linearity analysis showed a good correlation when the GAD-Ab in serum samples ranged from 40.3 to 664 U/ml and the detection limit of measurement was 3.6 U/ml. The results from Diabetes Autoantibody Standardization Program (DASP) 2005 showed that the sensitivity and specificity for GAD-Ab were 78% (39 positive among 50 new-onset T1DM) and 98% (2 positive among 100 healthy

  8. Expression of glutamic acid decarboxylase and identification of GABAergic cells in the ischemic rat dentate gyrus

    Müller, Georg Johannes; Dogonowski, Anne-Marie; Finsen, Bente; Johansen, Flemming Fryd

    2006-01-01

    parallel, we investigated the colocalization of the cell death marker Fluorojade B (FJB) with somatostatin- or GAD67-immunoreactivity in hilus of control and ischemic rats. Although the majority of FJB positive cells also contained somatostatin, a small number of GAD67 immunoreactive neurons contained FJB...

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

    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 py...

  10. Contribution of glutamate decarboxylase in Lactobacillus reuteri to acid resistance and persistence in sourdough fermentation

    Gänzle Michael G; Schlicht Sabine; Su Marcia S

    2011-01-01

    Abstract Background Acid stress impacts the persistence of lactobacilli in industrial sourdough fermentations, and in intestinal ecosystems. However, the contribution of glutamate to acid resistance in lactobacilli has not been demonstrated experimentally, and evidence for the contribution of acid resistance to the competitiveness of lactobacilli in sourdough is lacking. It was therefore the aim of this study to investigate the ecological role of glutamate decarboxylase in L. reuteri. Results...

  11. Production of dopamine by aromatic L-amino acid decarboxylase cells after spinal cord injury

    Ren, Liqun; Wienecke, Jacob; Hultborn, Hans;

    2016-01-01

    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 from 5-hydroxytryptophan after spinal cord injury (SCI...... inhibitor (pargyline) co-application, systemic administration of L-dopa resulted in ~ 94% of AADC cells to become 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....... 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...

  12. Lack of support for the association between GAD2 polymorphisms and severe human obesity.

    Michael M Swarbrick

    2005-09-01

    Full Text Available The demonstration of association between common genetic variants and chronic human diseases such as obesity could have profound implications for the prediction, prevention, and treatment of these conditions. Unequivocal proof of such an association, however, requires independent replication of initial positive findings. Recently, three (-243 A>G, +61450 C>A, and +83897 T>A single nucleotide polymorphisms (SNPs within glutamate decarboxylase 2 (GAD2 were found to be associated with class III obesity (body mass index > 40 kg/m2. The association was observed among 188 families (612 individuals segregating the condition, and a case-control study of 575 cases and 646 lean controls. Functional data supporting a pathophysiological role for one of the SNPs (-243 A>G were also presented. The gene GAD2 encodes the 65-kDa subunit of glutamic acid decarboxylase-GAD65. In the present study, we attempted to replicate this association in larger groups of individuals, and to extend the functional studies of the -243 A>G SNP. Among 2,359 individuals comprising 693 German nuclear families with severe, early-onset obesity, we found no evidence for a relationship between the three GAD2 SNPs and obesity, whether SNPs were studied individually or as haplotypes. In two independent case-control studies (a total of 680 class III obesity cases and 1,186 lean controls, there was no significant relationship between the -243 A>G SNP and obesity (OR = 0.99, 95% CI 0.83-1.18, p = 0.89 in the pooled sample. These negative findings were recapitulated in a meta-analysis, incorporating all published data for the association between the -243G allele and class III obesity, which yielded an OR of 1.11 (95% CI 0.90-1.36, p = 0.28 in a total sample of 1,252 class III obese cases and 1,800 lean controls. Moreover, analysis of common haplotypes encompassing the GAD2 locus revealed no association with severe obesity in families with the condition. We also obtained functional data for the

  13. EFFECT OF AERO-/ANAEROBIOSIS ON DECARBOXYLASE ACTIVITY OF SELECTED LACTIC ACID BACTERIA

    Stanislav Kráčmar; Vladimír Dráb; Tereza Podešvová; Eva Pollaková; Leona Buňková; František Buňka

    2010-01-01

    Biogenic amines are undesirable compounds produced in foods mainly through bacterial decarboxylase activity. The aim of this study was to investigate some environmental conditions (particularly aero/anaerobiosis, sodium chloride concentration (0–2% w/w), and amount of lactose (0–1% w/w)) on the activity of tyrosine decarboxylase enzymes of selected six technological important Lactococcus lactis strains. The levels of parameters tested were chosen according to real situation in fer...

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

    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

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

    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

  16. Type 1 diabetes and GAD65 limbic encephalitis: a case report of a 10-year-old girl.

    Grilo, Ema; Pinto, Joana; Caetano, Joana Serra; Pereira, Helena; Cardoso, Patrícia; Cardoso, Rita; Dinis, Isabel; Pereira, Cristina; Fineza, Isabel; Mirante, Alice

    2016-08-01

    Limbic encephalitis is a rare neurological disorder that may be difficult to recognize. Clinical features include memory impairment, temporal lobe seizures and affective disturbance. We report the case of a 10-year-old girl with type 1 diabetes mellitus that presented with seizures, depressed mood and memory changes. The diagnosis of glutamic acid decarboxylase 65 (GAD65) mediated limbic encephalitis relied on cerebral magnetic resonance imaging lesions and high serological and cerebrospinal fluid GAD65-antibodies titers. High-dose steroidal therapy was started with clinical improvement. Relapse led to a second high-dose steroid treatment followed by rituximab with remission. A correlation between serum GAD65-antibodies levels and symptoms was found, demonstrating GAD65-antibodies titers may be useful for clinical follow-up and immunotherapy guidance. This report raises awareness of this serious neurological condition that may be associated with type 1 diabetes, underlining the importance of an early diagnosis and prompt treatment for a better prognosis. PMID:27115322

  17. Epigenetic Suppression of GADs Expression is Involved in Temporal Lobe Epilepsy and Pilocarpine-Induced Mice Epilepsy.

    Wang, Jin-Gang; Cai, Qing; Zheng, Jun; Dong, Yu-Shu; Li, Jin-Jiang; Li, Jing-Chen; Hao, Guang-Zhi; Wang, Chao; Wang, Ju-Lei

    2016-07-01

    Recent studies have shown that histone acetylation is involved with the regulation of enzyme glutamate decarboxylases (GADs), including GAD67 and GAD65. Here, we investigated the histone acetylation modifications of GADs in the pathogenesis of epilepsy and explored the therapeutic effect of a novel second-generation histone deacetylase inhibitor (HDACi) JNJ-26481585 in epilepsy animals. We revealed the suppression of GADs protein and mRNA level, and histone hypoacetylation in patients with temporal lobe epilepsy and pilocarpine-induced epilepsy mice model. Double-immunofluorescence also indicated that the hypoacetyl-H3 was located in hippocampal GAD67/GAD65 positive neurons in epilepsy mice. JNJ-26481585 significantly reversed the decrease of the GAD67/GAD65 both protein and mRNA levels, and the histone hypoacetylation of GABAergic neurons in epilepsy mice. Meanwhile, single-cell real-time PCR performed in GFP-GAD67/GAD65 transgenic mice demonstrated that JNJ-26481585 induced increase of GAD67/GAD65 mRNA level in GABAergic neurons. Furthermore, JNJ-26481585 significantly alleviated the epileptic seizures in mice model. Together, our findings demonstrate inhibition of GADs gene via histone acetylation plays an important role in the pathgenesis of epilepsy, and suggest JNJ-26481585 as a promising therapeutic strategy for epilepsy. PMID:27220336

  18. Glutamic acid decarboxylase 65 autoantibody levels discriminate two subtypes of latent autoimmune diabetes in adults

    李霞; 杨琳; 周智广; 黄干; 颜湘

    2003-01-01

    Objective To compare the clinical characteristics between type 2 diabetes mellitus (T2DM) and latent autoimmune diabetes in adults (LADA) with different titers of glutamic acid decarboxylase autoantibody (GADA) and to define the two distinct subtypes of LADA.Methods Sera of 750 patients with an initial diagnosis of T2DM from central south of China were screened for GADA using a radioligand assay. The distribution and frequency of GADA levels were described. Two hundred and ninety-five patients were divided into the T2DM group (n=233) and the LADA group (n=62) to compare the age of onset, body mass index, HbA1c, C-peptide, hypertension, dyslipidemia and chronic diabetic complications. Furthermore, LADA patients with different GADA titers were subdivided to analyze the same indexes as the above. Results The prevalence of LADA (defined as GADA≥0.05, namely GADA positive) was 9.7% in the 750 initially diagnosed type 2 diabetic patients. Compared with T2DM, LADA patients were younger at their ages of onset, had lower C-peptide and body mass index, and also had less cases with hypertension and with dyslipidemia. However, only patients with high titer of GADA had poorer beta cell functions and less diabetic complications compared to T2DM and low GADA titer of LADA patients. Patients with low GADA titer were similar to T2DM patients, except that they were prone to develop ketosis more frequently.Conclusions Two clinically distinct subtypes of LADA can be identified by GADA levels in patients initially-diagnosed as type 2 diabetes. Patients with high titer of GADA (GADA≥0.5) subsequently develop more insulin dependency, which are classified as LADA-type 1; while those with lower GADA titer (0.05≤GADA<0.5) and having clinical and metabolic phenotypes of type 2 diabetes are classified as LADA-type 2.

  19. Characterization of phenolic acid reductase and decarboxylase activities of lactic acid bateria

    Soares, Ana de Seabra Leão Ferreira

    2014-01-01

    Hydroxycinnamic acids are natural constituents of grape juice and wine, and are precursors of volatile phenols produced by yeasts and lactic acid bacteria (LAB). The organoleptic defects due to the presence of this volatile phenols are usually associated with “animal”, “horsey”, “leather”, “phenolic” or “spicy” aromatic notes. The most common pathway for the degradation of hydroxycinnamic acids involves two enzymes. In first place, it occurs a decarboxylation by the phenolic acid decarboxylas...

  20. Structural basis of enzymatic activity for the ferulic acid decarboxylase (FADase from Enterobacter sp. Px6-4.

    Wen Gu

    Full Text Available 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.

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

    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 s...

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

    The crystal structure of recombinant UbiX has been determined to 1.5 Å resolution. 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

  3. EFFECT OF AERO-/ANAEROBIOSIS ON DECARBOXYLASE ACTIVITY OF SELECTED LACTIC ACID BACTERIA

    Stanislav Kráčmar

    2010-05-01

    Full Text Available Biogenic amines are undesirable compounds produced in foods mainly through bacterial decarboxylase activity. The aim of this study was to investigate some environmental conditions (particularly aero/anaerobiosis, sodium chloride concentration (0–2% w/w, and amount of lactose (0–1% w/w on the activity of tyrosine decarboxylase enzymes of selected six technological important Lactococcus lactis strains. The levels of parameters tested were chosen according to real situation in fermented dairy products technology (especially cheese-making. Tyramine was determined by the ion-exchange chromatography with post-column ninhydrine derivatization and spectrophotometric detection. Tyrosine decarboxylation occurred during the active growth phase. Under the model conditions used, oxygen availability had influence on tyramine production, anaerobiosis seemed to favour the enzyme activity because all L. lactis strains produced higher tyramine amount. doi:10.5219/43

  4. Spinal cord hemisection facilitates aromatic L-amino acid decarboxylase cells to produce serotonin in the subchronic but not the chronic phase

    Azam, Bushra; Wienecke, Jacob; Jensen, Dennis Bo;

    2015-01-01

    Neuromodulators, such as serotonin (5-hydroxytryptamine, 5-HT) and noradrenalin, play an essential role in regulating the motor and sensory functions in the spinal cord. We have previously shown that in the rat spinal cord the activity of aromatic L-amino acid decarboxylase (AADC) cells to produce...

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

    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

  6. Association between a polymorphism of the 65K-glutamate decarboxylase gene and insulin-dependent diabetes mellitus

    Kure, S.; Aoki, Y.; Narisawa, K. [Tohoku Univ. School of Medicine, Sendai (Japan)] [and others

    1994-09-01

    Autoimmunity against 65K-glutamate decarboxylase (GAD65), one of two forms of the {gamma}-aminobutyric acid-synthesizing enzyme, is commonly associated with insulin-dependent diabetes mellitus (IDDM). To study the predisposing effect of the GAD65 genotype on IDDM, we performed a case-control study screening an association between a newly-identified GAD65 polymorphism and IDDM in the Japanese population. The identified polymorphism was a microsatellite that was located in an intron near the 3{prime} end of the GAD65 gene consisting of variable numbers of a (CA)-dinucleotide repeat. We amplified the polymorphic region by polymerase chain reaction, and, for each individual in the control group (n=254) and the IDDM group (n=108), determined a pair of (CA)-repeat numbers, each number derived from one or the other of their alleles. In both groups we found 13 allelic variants with different repeat numbers, ranging from 19 to 31 repeats of the (CA) dinucleotide. The most frequent allelic variant in the IDDM group was 20 repeats; (CA){sub 20}. A higher frequency of a genotype containing two (CA){sub 20} alleles (p=0.005) was observed in the IDDM group (41.7%) compared with the control group (26.8%). Odds ratio (a 95% confidence interval) for a heterozygote or a homozygote of (CA){sub 20} versus a subject without (CA){sub 20} was 1.2 (0.66-2.25) and 2.23 (1.18-4.21), respectively. No significant association was observed between the (CA)-repeat genotype and the appearance of anti-GAD antibodies in the patients whose duration of the diabetes was less than 4 years (n=35). Therefore, genetic variations in GAD65 appears to be associated with IDDM susceptibility.

  7. Current concepts on the physiology and genetics of neurotransmitters-mediating enzyme-aromatic L-amino acid decarboxylase

    Two most important neurotransmitters, dopamine and serotonin are mediated by the enzyme aromatic L-amino acid decarboxylase (AADC). Because of their importance in the regulation of neuronal functions, behaviour and emotion of higher animals, many researchers are working on this enzyme to elucidate its physiological properties, structure and genetic aspects. We have discovered this enzyme in the mammalian blood, we established sensitive assay methods for the assay of the activities of this enzyme. We have made systematic studies on this enzyme in the tissues and brains of rats, and human subjects. We have found an endogenous inhibitor of this enzyme in the monkey's blood. The amino acid sequences of human AADC has been compared to rat or bovine. A full-length cDNA clone encoding human AADC has been isolated. Very recently the structure of human AADC gene including 5'-flaking region has been characterized and the transcriptional starting point has been determined. The human AADC gene assigned to chromosome 7. Up-to-date research data have shown that AADC is encoded by a single gene. Recently two patients with AADC deficiency were reported. This paper describes the systematic up-to-date review studies on AADC. (author). 62 refs, 5 figs, 8 tabs

  8. Screening for Generalized Anxiety Disorder (GAD)

    ... Conference & Education Membership Journal & Multimedia Resources Awards Consumers Screening for Generalized Anxiety Disorder (GAD) Main navigation FAQs Screen Yourself Screening for Depression Screening for Generalized Anxiety Disorder (GAD) ...

  9. IGF2BP2 alternative variants associated with glutamic acid decarboxylase antibodies negative diabetes in Malaysian subjects.

    Sameer D Salem

    Full Text Available 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.

  10. Correlations of Clusters of Non-Convulsive Seizure and Magnetic Resonance Imaging in a Case With GAD65-Positive Autoimmune Limbic Encephalitis.

    Gardner, Rachael; Rangaswamy, Rajesh; Peng, Yen-Yi

    2016-08-01

    With the increased availability of laboratory tests, glutamic acid decarboxylase (GAD) antibody-positive limbic encephalitis has become an emerging diagnosis. The myriad symptoms of limbic encephalitis make the diagnosis challenging. Symptoms range from seizures, memory loss, dementia, confusion, to psychosis. We present a case of a 21-year-old female with GAD65 antibody-positive limbic encephalitis. The case is unique because the clinical course suggests that non-convulsive seizures are the major cause of this patient's clinical manifestations. The following is the thesis: systemic autoimmune disease, associated with the GAD65 antibody, gives rise to seizures, in particular, non-convulsive seizures. Temporal lobes happen to be the most susceptible sites to develop seizures. The greater part of these seizures can be non-convulsive and hard to recognize without electroencephalogram (EEG) monitoring. The variable symptoms mirror the severity and locations of these seizures. The magnetic resonance imaging (MRI) signal abnormities in the bilateral hippocampus, fornix, and mammillary body correlate with the density of these seizures in the similar manner, which suggests it is secondary to post-ictal edema. PMID:27429684

  11. Escherichia coli K-12 survives anaerobic exposure at pH 2 without RpoS, Gad, or hydrogenases, but shows sensitivity to autoclaved broth products.

    Daniel P Riggins

    Full Text Available Escherichia coli and other enteric bacteria survive exposure to extreme acid (pH 2 or lower in gastric fluid. Aerated cultures survive via regulons expressing glutamate decarboxylase (Gad, activated by RpoS, cyclopropane fatty acid synthase (Cfa and others. But extreme-acid survival is rarely tested under low oxygen, a condition found in the stomach and the intestinal tract. We observed survival of E. coli K-12 W3110 at pH 1.2-pH 2.0, conducting all manipulations (overnight culture at pH 5.5, extreme-acid exposure, dilution and plating in a glove box excluding oxygen (10% H2, 5% CO2, balance N2. With dissolved O2 concentrations maintained below 6 µM, survival at pH 2 required Cfa but did not require GadC, RpoS, or hydrogenases. Extreme-acid survival in broth (containing tryptone and yeast extract was diminished in media that had been autoclaved compared to media that had been filtered. The effect of autoclaved media on extreme-acid survival was most pronounced when oxygen was excluded. Exposure to H2O2 during extreme-acid treatment increased the death rate slightly for W3110 and to a greater extent for the rpoS deletion strain. Survival at pH 2 was increased in strains lacking the anaerobic regulator fnr. During anaerobic growth at pH 5.5, strains deleted for fnr showed enhanced transcription of acid-survival genes gadB, cfa, and hdeA, as well as catalase (katE. We show that E. coli cultured under oxygen exclusion (<6 µM O2 requires mechanisms different from those of aerated cultures. Extreme acid survival is more sensitive to autoclave products under oxygen exclusion.

  12. Early development of GABAergic cells of the retina in sharks: an immunohistochemical study with GABA and GAD antibodies.

    Ferreiro-Galve, Susana; Candal, Eva; Carrera, Iván; Anadón, Ramón; Rodríguez-Moldes, Isabel

    2008-09-01

    We studied the ontogeny and organization of GABAergic cells in the retina of two elasmobranches, the lesser-spotted dogfish (Scyliorhinus canicula) and the brown shyshark (Haploblepharus fuscus) by using immunohistochemistry for gamma-aminobutyric acid (GABA) and glutamic acid decarboxylase (GAD). Both antibodies revealed the same pattern of immunoreactivity and both species showed similar organization of GABAergic cells. GABAergic cells were first detected in neural retina of embryos at stage 26, which showed a neuroepithelial appearance without any layering. In stages 27-29 the retina showed similar organization but the number of neuroblastic GABAergic cells increased. When layering became apparent in the central retina (stage-30 embryos), GABAergic cells mainly appeared organized in the outer and inner retina, and GABAergic processes and fibres were seen in the primordial inner plexiform layer (IPL), optic fibre layer and optic nerve stalk. In stage-32 embryos, layering was completed in the central retina, where immunoreactivity appeared in perikarya of the horizontal cell layer, inner nuclear layer and ganglion cell layer, and in numerous processes coursing in the IPL, optic fibre layer and optic nerve. From stage 32 to hatching (stage 34), the layered retina extends from centre-to-periphery, recapitulating that observed in the central retina at earlier stages. In adults, GABA/GAD immunoreactivity disappears from the horizontal cell layer except in the marginal retina. Our results indicate that the source of GABA in the shark retina can be explained by its synthesis by GAD. Such synthesis precedes layering and synaptogenesis, thus supporting a developmental role for GABA in addition to act as neurotransmitter and neuromodulator. PMID:18524536

  13. Differential Regulation of Glutamic Acid Decarboxylase Gene Expression after Extinction of a Recent Memory vs. Intermediate Memory

    Sangha, Susan; Ilenseer, Jasmin; Sosulina, Ludmila; Lesting, Jorg; Pape, Hans-Christian

    2012-01-01

    Extinction reduces fear to stimuli that were once associated with an aversive event by no longer coupling the stimulus with the aversive event. Extinction learning is supported by a network comprising the amygdala, hippocampus, and prefrontal cortex. Previous studies implicate a critical role of GABA in extinction learning, specifically the GAD65…

  14. The use of L-lysine decarboxylase as a means to separate amino acids by electrodialysis

    Teng, Y.; Scott, E.L.; Zeeland, van A.N.T.; Sanders, J.P.M.

    2011-01-01

    Amino acids (AA's) are interesting materials as feedstocks for the chemical industry as they contain chemical functionalities similar to conventional petrochemicals. This offers the possibility to circumvent process steps, energy and reagents. AA's can be obtained by the hydrolysis of potentially in

  15. An autocrine γ-aminobutyric acid signaling system exists in pancreatic β-cell progenitors of fetal and postnatal mice

    Feng, Mary M; Xiang, Yun-Yan; Wang, Shuanglian; Lu, Wei-Yang

    2013-01-01

    Gamma-aminobutyric acid (GABA) is produced and secreted by adult pancreatic β-cells, which also express GABA receptors mediating autocrine signaling and regulating β-cell proliferation. However, whether the autocrine GABA signaling involves in β-cell progenitor development or maturation remains uncertain. By means of immunohistochemistry we analyzed the expression profiles of the GABA synthesizing enzyme glutamic acid decarboxylase (GAD) and the α1-subunit of type-A GABA receptor (GABAARα1) i...

  16. GABA metabolism pathway genes, UGA1 and GAD1, regulate replicative lifespan in Saccharomycescerevisiae

    Highlights: →We demonstrate that two genes in the yeast GABA metabolism pathway affect aging. → Deletion of the UGA1 or GAD1 genes extends replicative lifespan. → Addition of GABA to wild-type cultures has no effect on lifespan. → Intracellular GABA levels do not differ in longevity mutants and wild-type cells. → Levels of tricarboxylic acid cycle intermediates positively correlate with lifespan. -- Abstract: Many of the genes involved in aging have been identified in organisms ranging from yeast to human. Our previous study showed that deletion of the UGA3 gene-which encodes a zinc-finger transcription factor necessary for γ-aminobutyric acid (GABA)-dependent induction of the UGA1 (GABA aminotransferase), UGA2 (succinate semialdehyde dehydrogenase), and UGA4 (GABA permease) genes-extends replicative lifespan in the budding yeast Saccharomycescerevisiae. Here, we found that deletion of UGA1 lengthened the lifespan, as did deletion of UGA3; in contrast, strains with UGA2 or UGA4 deletions exhibited no lifespan extension. The Δuga1 strain cannot deaminate GABA to succinate semialdehyde. Deletion of GAD1, which encodes the glutamate decarboxylase that converts glutamate into GABA, also increased lifespan. Therefore, two genes in the GABA metabolism pathway, UGA1 and GAD1, were identified as aging genes. Unexpectedly, intracellular GABA levels in mutant cells (except for Δuga2 cells) did not differ from those in wild-type cells. Addition of GABA to culture media, which induces transcription of the UGA structural genes, had no effect on replicative lifespan of wild-type cells. Multivariate analysis of 1H nuclear magnetic resonance spectra for the whole-cell metabolite levels demonstrated a separation between long-lived and normal-lived strains. Gas chromatography-mass spectrometry analysis of identified metabolites showed that levels of tricarboxylic acid cycle intermediates positively correlated with lifespan extension. These results strongly suggest

  17. GABA metabolism pathway genes, UGA1 and GAD1, regulate replicative lifespan in Saccharomycescerevisiae

    Kamei, Yuka; Tamura, Takayuki [Department of Bioscience, Faculty of Bioscience, Nagahama Institute of Bio-Science and Technology, 1266 Tamura, Nagahama, Shiga 526-0829 (Japan); Yoshida, Ryo [Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Ohta, Shinji [Department of Bioscience, Faculty of Bioscience, Nagahama Institute of Bio-Science and Technology, 1266 Tamura, Nagahama, Shiga 526-0829 (Japan); Fukusaki, Eiichiro [Department of Biotechnology, Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita, Osaka 565-0871 (Japan); Mukai, Yukio, E-mail: y_mukai@nagahama-i-bio.ac.jp [Department of Bioscience, Faculty of Bioscience, Nagahama Institute of Bio-Science and Technology, 1266 Tamura, Nagahama, Shiga 526-0829 (Japan)

    2011-04-01

    Highlights: {yields}We demonstrate that two genes in the yeast GABA metabolism pathway affect aging. {yields} Deletion of the UGA1 or GAD1 genes extends replicative lifespan. {yields} Addition of GABA to wild-type cultures has no effect on lifespan. {yields} Intracellular GABA levels do not differ in longevity mutants and wild-type cells. {yields} Levels of tricarboxylic acid cycle intermediates positively correlate with lifespan. -- Abstract: Many of the genes involved in aging have been identified in organisms ranging from yeast to human. Our previous study showed that deletion of the UGA3 gene-which encodes a zinc-finger transcription factor necessary for {gamma}-aminobutyric acid (GABA)-dependent induction of the UGA1 (GABA aminotransferase), UGA2 (succinate semialdehyde dehydrogenase), and UGA4 (GABA permease) genes-extends replicative lifespan in the budding yeast Saccharomycescerevisiae. Here, we found that deletion of UGA1 lengthened the lifespan, as did deletion of UGA3; in contrast, strains with UGA2 or UGA4 deletions exhibited no lifespan extension. The {Delta}uga1 strain cannot deaminate GABA to succinate semialdehyde. Deletion of GAD1, which encodes the glutamate decarboxylase that converts glutamate into GABA, also increased lifespan. Therefore, two genes in the GABA metabolism pathway, UGA1 and GAD1, were identified as aging genes. Unexpectedly, intracellular GABA levels in mutant cells (except for {Delta}uga2 cells) did not differ from those in wild-type cells. Addition of GABA to culture media, which induces transcription of the UGA structural genes, had no effect on replicative lifespan of wild-type cells. Multivariate analysis of {sup 1}H nuclear magnetic resonance spectra for the whole-cell metabolite levels demonstrated a separation between long-lived and normal-lived strains. Gas chromatography-mass spectrometry analysis of identified metabolites showed that levels of tricarboxylic acid cycle intermediates positively correlated with lifespan

  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.

    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. Pancreatic beta cells express two autoantigenic forms of glutamic acid decarboxylase, a 65-kDa hydrophilic form and a 64-kDa amphiphilic form which can be both membrane-bound and soluble

    Christgau, S; Schierbeck, H; Aanstoot, H J;

    1991-01-01

    The 64-kDa pancreatic beta-cell autoantigen, which is a target of autoantibodies associated with early as well as progressive stages of beta-cell destruction, resulting in insulin-dependent diabetes (IDDM) in humans, has been identified as the gamma-aminobutyric acid-synthesizing enzyme glutamic...... compartment and hydrophobicity. A major portion of GAD64 is hydrophobic and firmly membrane-anchored and can only be released from membrane fractions by detergent. A second portion is hydrophobic but soluble or of a low membrane avidity, and a third minor portion is soluble and hydrophilic. All the GAD64...

  20. Function and evolution of the serotonin-synthetic bas-1 gene and other aromatic amino acid decarboxylase genes in Caenorhabditis

    Hare Emily E

    2004-08-01

    Full Text Available Abstract Background Aromatic L-amino acid decarboxylase (AADC enzymes catalyze the synthesis of biogenic amines, including the neurotransmitters serotonin and dopamine, throughout the animal kingdom. These neurotransmitters typically perform important functions in both the nervous system and other tissues, as illustrated by the debilitating conditions that arise from their deficiency. Studying the regulation and evolution of AADC genes is therefore desirable to further our understanding of how nervous systems function and evolve. Results In the nematode C. elegans, the bas-1 gene is required for both serotonin and dopamine synthesis, and maps genetically near two AADC-homologous sequences. We show by transformation rescue and sequencing of mutant alleles that bas-1 encodes an AADC enzyme. Expression of a reporter construct in transgenics suggests that the bas-1 gene is expressed, as expected, in identified serotonergic and dopaminergic neurons. The bas-1 gene is one of six AADC-like sequences in the C. elegans genome, including a duplicate that is immediately downstream of the bas-1 gene. Some of the six AADC genes are quite similar to known serotonin- and dopamine-synthetic AADC's from other organisms whereas others are divergent, suggesting previously unidentified functions. In comparing the AADC genes of C. elegans with those of the congeneric C. briggsae, we find only four orthologous AADC genes in C. briggsae. Two C. elegans AADC genes – those most similar to bas-1 – are missing from C. briggsae. Phylogenetic analysis indicates that one or both of these bas-1-like genes were present in the common ancestor of C. elegans and C. briggsae, and were retained in the C. elegans line, but lost in the C. briggsae line. Further analysis of the two bas-1-like genes in C. elegans suggests that they are unlikely to encode functional enzymes, and may be expressed pseudogenes. Conclusions The bas-1 gene of C. elegans encodes a serotonin- and dopamine

  1. Anti-Yo and anti-glutamic acid decarboxylase antibodies presenting in carcinoma of the uterus with paraneoplastic cerebellar degeneration: a case report

    Panegyres Peter K

    2012-06-01

    Full Text Available Abstract Introduction Paraneoplastic cerebellar degeneration is a rare non-metastatic manifestation of malignancy. In this report, to the best of our knowledge we describe for the first time a diagnosis of paraneoplastic cerebellar degeneration several months prior to the diagnosis of clear carcinoma of the uterus. Case presentation A 75-year-old Caucasian woman manifested a rapidly progressive cerebellar syndrome with nystagmus, past-pointing, dysdiadochokinesis, dysarthria, truncal ataxia and titubation. The paraneoplastic cerebellar degeneration was associated with anti-Yo and anti-glutamic acid decarboxylase antibodies. 14-3-3 protein was detected in the cerebrospinal fluid. She was treated with intravenous immunoglobulin prior to laparotomy, hysterectomy and bilateral salpingoophorectomy. Our patient has survived for three years following diagnosis and treatment. Conclusions To the best of our knowledge this is the first report of an association of clear cell carcinoma of the uterus and paraneoplastic cerebellar degeneration with both anti-Yo and anti-glutamic acid decarboxylase antibodies. The findings imply that both antibodies contributed to the fulminating paraneoplastic cerebellar degeneration observed in our patient, and this was of such severity it resulted in the release of 14-3-3 protein in the cerebrospinal fluid, a marker of neuronal death.

  2. Disease progression and search for monogenic diabetes among children with new onset type 1 diabetes negative for ICA, GAD- and IA-2 Antibodies

    Pörksen, Sven; Laborie, Lene; Nielsen, Lotte;

    2010-01-01

    BACKGROUND:To investigate disease progression the first 12 months after diagnosis in children with type 1 diabetes negative (AAB negative) for pancreatic autoantibodies [islet cell autoantibodies(ICA), glutamic acid decarboxylase antibodies (GADA) and insulinoma-associated antigen-2 antibodies (IA......-2A)]. Furthermore the study aimed at determining whether mutations in KCNJ11, ABCC8, HNF1A, HNF4A or INS are common in AAB negative diabetes.MATERIALS AND METHODS:In 261 newly diagnosed children with type 1 diabetes, we measured residual î-cell function, ICA, GADA, and IA-2A at 1, 6 and 12 months...... treatment after four weeks on 1.0-1.2 mg/kg/24 h glibenclamide.CONCLUSION:GAD, IA-2A, and ICA negative children with new onset type 1 diabetes have slower disease progression as assessed by residual beta-cell function and improved glycemic control 12 months after diagnosis. One out of 24 had a mutation...

  3. Combinational spinal GAD65 gene delivery and systemic GABA-mimetic treatment for modulation of spasticity.

    Osamu Kakinohana

    Full Text Available BACKGROUND: Loss of GABA-mediated pre-synaptic inhibition after spinal injury plays a key role in the progressive increase in spinal reflexes and the appearance of spasticity. Clinical studies show that the use of baclofen (GABA(B receptor agonist, while effective in modulating spasticity is associated with major side effects such as general sedation and progressive tolerance development. The goal of the present study was to assess if a combined therapy composed of spinal segment-specific upregulation of GAD65 (glutamate decarboxylase gene once combined with systemic treatment with tiagabine (GABA uptake inhibitor will lead to an antispasticity effect and whether such an effect will only be present in GAD65 gene over-expressing spinal segments. METHODS/PRINCIPAL FINDINGS: Adult Sprague-Dawley (SD rats were exposed to transient spinal ischemia (10 min to induce muscle spasticity. Animals then received lumbar injection of HIV1-CMV-GAD65 lentivirus (LVs targeting ventral α-motoneuronal pools. At 2-3 weeks after lentivirus delivery animals were treated systemically with tiagabine (4, 10, 20 or 40 mg/kg or vehicle and the degree of spasticity response measured. In a separate experiment the expression of GAD65 gene after spinal parenchymal delivery of GAD65-lentivirus in naive minipigs was studied. Spastic SD rats receiving spinal injections of the GAD65 gene and treated with systemic tiagabine showed potent and tiagabine-dose-dependent alleviation of spasticity. Neither treatment alone (i.e., GAD65-LVs injection only or tiagabine treatment only had any significant antispasticity effect nor had any detectable side effect. Measured antispasticity effect correlated with increase in spinal parenchymal GABA synthesis and was restricted to spinal segments overexpressing GAD65 gene. CONCLUSIONS/SIGNIFICANCE: These data show that treatment with orally bioavailable GABA-mimetic drugs if combined with spinal-segment-specific GAD65 gene overexpression can

  4. 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.

    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

  5. Generalized Anxiety Disorder (GAD): When Worry Gets Out of Control

    ... to have GAD? For More Information Share Generalized Anxiety Disorder (GAD): When Worry Gets Out of Control ... go badly? If so, you may have an anxiety disorder called generalized anxiety disorder (GAD). What is ...

  6. Immunohistochemical evidence for colocalization of gamma-aminobutyric acid and serotonin in neurons of the ventral medulla oblongata projecting to the spinal cord.

    Millhorn, D E; Hökfelt, T; Seroogy, K; Oertel, W; Verhofstad, A A; Wu, J Y

    1987-04-28

    Fluorescence immunohistochemistry was used to analyze the medulla oblongata of colchicine-treated rats that had been incubated with guinea pig antibodies to serotonin (5-HT) and either rabbit or sheep antibodies to glutamic acid decarboxylase (GAD). Numerous cells in the rostral ventrolateral medulla in the region of nucleus raphe magnus were immunostained for either 5-HT or GAD. A substantial number of neurons showed positive immunoreactivity for both substances, and were most frequently observed in the lateral aspect of nucleus raphe magnus. In addition, a number of the 5-HT/GAD-containing neurons were retrogradely labelled with Fast blue dye that had been injected into the thoracic spinal cord. This work provides evidence for colocalization of the classical neurotransmitters 5-HT and GABA in single cells of the ventral medulla oblongata, some of which project to the spinal cord. PMID:3555707

  7. Repression of btuB gene transcription in Escherichia coli by the GadX protein

    Hu Wensi S

    2011-02-01

    Full Text Available Abstract Background BtuB (B twelve uptake is an outer membrane protein of Escherichia coli, it serves as a receptor for cobalamines uptake or bactericidal toxin entry. A decrease in the production of the BtuB protein would cause E. coli to become resistant to colicins. The production of BtuB has been shown to be regulated at the post-transcriptional level. The secondary structure switch of 5' untranslated region of butB and the intracellular concentration of adenosylcobalamin (Ado-Cbl would affect the translation efficiency and RNA stability of btuB. The transcriptional regulation of btuB expression is still unclear. Results To determine whether the btuB gene is also transcriptionally controlled by trans-acting factors, a genomic library was screened for clones that enable E. coli to grow in the presence of colicin E7, and a plasmid carrying gadX and gadY genes was isolated. The lacZ reporter gene assay revealed that these two genes decreased the btuB promoter activity by approximately 50%, and the production of the BtuB protein was reduced by approximately 90% in the presence of a plasmid carrying both gadX and gadY genes in E. coli as determined by Western blotting. Results of electrophoretic mobility assay and DNase I footprinting indicated that the GadX protein binds to the 5' untranslated region of the btuB gene. Since gadX and gadY genes are more highly expressed under acidic conditions, the transcriptional level of btuB in cells cultured in pH 7.4 or pH 5.5 medium was examined by quantitative real-time PCR to investigate the effect of GadX. The results showed the transcription of gadX with 1.4-fold increase but the level of btuB was reduced to 57%. Conclusions Through biological and biochemical analysis, we have demonstrated the GadX can directly interact with btuB promoter and affect the expression of btuB. In conclusion, this study provides the first evidence that the expression of btuB gene is transcriptionally repressed by the acid

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

    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

  9. Positron emission tomographic studies on aromatic L-amino acid decarboxylase activity in vivo for L-dopa and 5-hydroxy-L-tryptophan in the monkey brain

    The regional brain kinetics following 5-hydroxy-L-(β-11 C)tryptophan and L-(β-11 C)DOPA intravenous injection was measured in twelve Rhesus monkeys using positron emission tomography (PET). The radiolabelled compounds were also injected together with various doses of unlabelled 5-hydroxy-L-tryptophan or L-DOPA. The radioactivity accumulated in the striatal region and the rate of increased utilization with time was calculated using a graphical method with back of the brain as a reference region. The rate constants for decarboxylation were 0.0070 ± 0.0007 (S. D) and 0.0121 ± 0.0010 min-1 for 5-hydroxy-L-(β-11 C)tryptophan and L-(β-11 C)DOPA, respectively. After concomitant injection with unlabelled 5-hydroxy-L-tryptophan, the rate constant of 5-hydroxy-L-(β-11 C)tryptophan decreased dose-dependently and a 50 percent reduction was seen with a dose of about 4 mg/kg of unlabelled compound. A decreased utilization rate of L-(β-11 C)DOPA was seen only after simultaneous injection of 30 mg/kg of either L-DOPA or 5-hydroxy-L-tryptophan. This capacity limitation was most likely interpreted as different affinity of the striatal aromatic amino acid decarboxylase for L-DOPA and 5-hydroxy-L-tryptophan, respectively

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

    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

  11. Knockout of GAD65 has major impact on synaptic GABA synthesized from astrocyte-derived glutamine

    Walls, Anne Byriel; Eyjolfsson, Elvar M.; Smeland, Olav B.;

    2011-01-01

    65 for maintenance of the highly compartmentalized intracellular and intercellular GABA homeostasis, GAD65 knockout and corresponding wild-type mice were injected with [1-(13)C]glucose and the astrocyte-specific substrate [1,2-(13)C]acetate. Synthesis of GABA from glutamine in the GABAergic synapses...... cortex and hippocampus. The GABA content in both brain regions was reduced by ∼20%. Moreover, it was revealed that GAD65 is crucial for maintenance of biosynthesis of synaptic GABA particularly by direct synthesis from astrocytic glutamine via glutamate. The GAD67 was found to be important for synthesis...... of GABA from glutamine both via direct synthesis and via a pathway involving mitochondrial metabolism. Furthermore, a severe neuronal hypometabolism, involving glycolysis and tricarboxylic acid (TCA) cycle activity, was observed in cerebral cortex of GAD65 knockout mice....

  12. RAPID DETERMINA TION OF L—GLUTAMIC ACID WITH AN ENZYME REACTOR OFL—GLUTAMIC DECARBOXYLASE IMMOBILIZED ON ION EXCHANGE RESIN

    WUGuoqi; LINGDaren; 等

    2001-01-01

    The preparation and characterization of an immobilized L-glutamic decarboxylase(GDC) were studied.This work is to 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 CO2 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 properties of the immobilized enzyme on CM-CADB were studied by investigating the initial ate of the enzyme reaction,the effect of various parameters on the immobilized GDC activity and its stability.An immobilized GDC enzyme column reactor matched with a flow injection system-ion analyzer coupled with CO2 electrode-data collection system made up the original form of the apparatus of biosensor for determining of L-glutamate acid.The limit of detection is 1.0×10-5M.The linearity response is in the range of 5×10-2-5×10-5M.The equation of linear regression of the calibration curve is y=43.3x+181.6(y is the milli-volt of electrical potential response,x is the logarithm of the concentration of the substrate of L-glutamate acid).The correlation coefficient equals 0.99.The coefficient of varioation equals 2.7%.

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

    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

  14. A unique insertion of low complexity amino acid sequence underlies protein-protein interaction in human malaria parasite orotate phosphoribosyltransferase and orotidine 5'-monophosphate decarboxylase

    Waranya Imprasittichai; Sittiruk Roytrakul; Sudaratana R Krungkrai; Jerapan Krungkrai

    2014-01-01

    Objective:To investigate the multienzyme complex formation of human malaria parasite Plasmodium falciparum(P. falciparum) orotate phosphoribosyltransferase(OPRT) and orotidine 5'-monophosphate decarboxylase(OMPDC), the fifth and sixth enzyme of the de novo pyrimidine biosynthetic pathway.Previously, we have clearly established that the two enzymes in the malaria parasite exist physically as a heterotetrameric(OPRT)2(OMPDC)2 complex containing two subunits each ofOPRT andOMPDC, and that the complex have catalytic kinetic advantages over the monofunctional enzyme.Methods:Both enzymes were cloned and expressed as recombinant proteins.The protein-protein interaction in the enzyme complex was identified using bifunctional chemical cross-linker, liquid chromatography-mass spectrometric analysis and homology modeling.Results:The unique insertions of low complexity region at the α2 and α5 helices of the parasiteOMPDC, characterized by single amino acid repeat sequence which was not found in homologous proteins from other organisms, was located on theOPRT-OMPDC interface.The structural models for the protein-protein interaction of the heterotetrameric(OPRT)2(OMPDC)2 multienzyme complex were proposed.Conclusions:Based on the proteomic data and structural modeling, it is surmised that the human malaria parasite low complexity region is responsible for theOPRT-OMPDC interaction.The structural complex of the parasite enzymes, thus, represents an efficient functional kinetic advantage, which in line with co-localization principles of evolutional origin, and allosteric control in protein-protein-interactions.

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

    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

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

    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

  17. Homozygosity for a missense mutation in the 67 kDa isoform of glutamate decarboxylase in a family with autosomal recessive spastic cerebral palsy: parallels with Stiff-Person Syndrome and other movement disorders

    Woods C Geoffrey

    2004-11-01

    Full Text Available Abstract Background Cerebral palsy (CP is an heterogeneous group of neurological disorders of movement and/or posture, with an estimated incidence of 1 in 1000 live births. Non-progressive forms of symmetrical, spastic CP have been identified, which show a Mendelian autosomal recessive pattern of inheritance. We recently described the mapping of a recessive spastic CP locus to a 5 cM chromosomal region located at 2q24-31.1, in rare consanguineous families. Methods Here we present data that refine this locus to a 0.5 cM region, flanked by the microsatellite markers D2S2345 and D2S326. The minimal region contains the candidate gene GAD1, which encodes a glutamate decarboxylase isoform (GAD67, involved in conversion of the amino acid and excitatory neurotransmitter glutamate to the inhibitory neurotransmitter γ-aminobutyric acid (GABA. Results A novel amino acid mis-sense mutation in GAD67 was detected, which segregated with CP in affected individuals. Conclusions This result is interesting because auto-antibodies to GAD67 and the more widely studied GAD65 homologue encoded by the GAD2 gene, are described in patients with Stiff-Person Syndrome (SPS, epilepsy, cerebellar ataxia and Batten disease. Further investigation seems merited of the possibility that variation in the GAD1 sequence, potentially affecting glutamate/GABA ratios, may underlie this form of spastic CP, given the presence of anti-GAD antibodies in SPS and the recognised excitotoxicity of glutamate in various contexts. Table 4 GAD1 single nucleotide substitutions detected on mutation analysis and occurring in sequences submitted to NCBI SNP database and in the literature. This is not a definitive list, but includes those described at the time of the mutational analysis. *Nucleotide positions were not provided by Maestrini et al. [47]. Source SNP position in mRNA, from the translational start site (bp Gene position of SNP(bp Amino acid change (ALappalainen et al. (2002 A(-478Del Exon

  18. Change of glutamic acid decarboxylase antibody and protein tyrosine phosphatase antibody in Chinese patients with acute-onset type 1 diabetes mellitus

    CHAO Chen; HUANG Gan; LI Xia; YANG Lin; LIN Jian; JIN Ping; LUO Shuo-ming

    2013-01-01

    Background Glutamic acid decarboxylase antibody (GADA) and protein tyrosine phosphatase antibody (IA-2A) are two major autoantibodies,which exert important roles in the process of type 1 diabetes mellitus (T1D).Our study aimed to investigate the changes in positivity and titers of GADA and IA-2A during the course of Chinese acute-onset T1D patients and their relationships with clinical features.Methods Two hundreds and forty-seven Chinese newly diagnosed acute-onset T1D patients were consecutively recruited.GADA and IA-2A were detected at the time of diagnosis,one year later,3-5 years later after diagnosis during the follow-up; all the clinical data were recorded and analyzed as well.Results During the course of acute-onset T1D,the majority of patients remained stable for GADA or IA-2A,however,a few patients changed from positivity to negativity and fewer patients converted from negativity to positivity.The prevalence of GADA was 56.3% at diagnosis,decreasing to 50.5% one year later,and 43.3% 3-5 years later while the corresponding prevalence of IA-2A were 32.8%,31.0% and 23.3%,respectively.The median GADA titers were 0.0825 at diagnosis,declining to 0.0585 one year later and 0.0383 3-5 years later (P <0.001),while the corresponding median titers were 0.0016,0.0010,0.0014 for IA-2A,respectively.Fasting C-peptide (FCP) and postprandial C-peptide 2 hours (PCP2h)levels of GADA or IA-2A negativity persistence patients were higher than those of positivity persistence and negativity conversion patients (P <0.05) which indicated GADA or IA-2A negativity persistence T1D patients had a less loss of β cell function.Conclusion Our data suggest that repeated detection of GADA and IA-2A are necessary for differential diagnosis of autoimmune diabetes and the indirect prediction of the β cell function in Chinese patients.

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

    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

  20. Histidine Decarboxylase in Enterobacteriaceae Revisited

    Wauters, Georges; Avesani, Véronique; Charlier, Jacqueline; Janssens, Michèle; Delmée, Michel

    2004-01-01

    With a modification of Taylor's decarboxylation broth, histidine decarboxylase was detected in Enterobacter aerogenes, Morganella morganii, Raoultella ornithinolytica, and some strains of Citrobacter youngae and Raoultella planticola. This method provides a useful confirmatory test for identification of E. aerogenes strains.

  1. Mesomere-derived glutamate decarboxylase-expressing blastocoelar mesenchyme cells of sea urchin larvae

    Hideki Katow

    2013-12-01

    The ontogenetic origin of blastocoelar glutamate decarboxylase (GAD-expressing cells (GADCs in larvae of the sea urchin Hemicentrotus pulcherrimus was elucidated. Whole-mount in situ hybridisation (WISH detected transcription of the gene that encodes GAD in H. pulcherrimus (Hp-gad in unfertilised eggs and all blastomeres in morulae. However, at and after the swimming blastula stage, the transcript accumulation was particularly prominent in clumps of ectodermal cells throughout the embryonic surface. During the gastrula stage, the transcripts also accumulated in the endomesoderm and certain blastocoelar cells. Consistent with the increasing number of Hp-gad transcribing cells, immunoblot analysis indicated that the relative abundance of Hp-Gad increased considerably from the early gastrula stage until the prism stage. The expression pattern of GADCs determined by immunohistochemistry was identical to the pattern of Hp-gad transcript accumulation determined using WISH. In early gastrulae, GADCs formed blastocoelar cell aggregates around the blastopore with primary mesenchyme cells. The increase in the number of blastocoelar GADCs was inversely proportional to the number of ectodermal GADCs ranging from a few percent of total GADCs in early gastrulae to 80% in late prism larvae; this depended on ingression of ectodermal GADCs into the blastocoel. Some of the blastocoelar GADCs were fluorescein-positive in the larvae that developed from the 16-cell stage chimeric embryos; these comprised fluorescein-labeled mesomeres and unlabelled macromeres and micromeres. Our finding indicates that some of the blastocoelar GADCs are derived from the mesomeres and thus they are the new group of mesenchyme cells, the tertiary mesenchyme cells.

  2. A fluorescence-coupled assay for gamma aminobutyric acid (GABA reveals metabolic stress-induced modulation of GABA content in neuroendocrine cancer.

    Joseph E Ippolito

    Full Text Available Pathways involved in the synthesis of the neurotransmitter gamma-aminobutyric acid (GABA have been implicated in the pathogenesis of high grade neuroendocrine (NE neoplasms as well as neoplasms from a non-NE lineage. Using The Cancer Genome Atlas, overexpression of the GABA synthetic enzyme, glutamate decarboxylase 1 (GAD1, was found to be associated with decreased disease free-survival in prostate adenocarcinoma and decreased overall survival in clear cell renal cell carcinomas. Furthermore, GAD1 was found to be expressed in castrate-resistant prostate cancer cell lines, but not androgen-responsive cell lines. Using a novel fluorescence-coupled enzymatic microplate assay for GABA mediated through reduction of resazurin in a prostate neuroendocrine carcinoma (PNEC cell line, acid microenvironment-induced stress increased GABA levels while alkaline microenvironment-induced stress decreased GABA through modulation of GAD1 and glutamine synthetase (GLUL activities. Moreover, glutamine but not glucose deprivation decreased GABA through modulation of GLUL. Consistent with evidence in prokaryotic and eukaryotic organisms that GABA synthesis mediated through GAD1 may play a crucial role in surviving stress, GABA may be an important mediator of stress survival in neoplasms. These findings identify GABA synthesis and metabolism as a potentially important pathway for regulating cancer cell stress response as well as a potential target for therapeutic strategies.

  3. Effect of Lathyrus sativus and vitamin C on the status of aromatic L-amino acid decarboxylase and dipeptidyl-aminopeptidase-IV in the central and peripheral tissues and serum of guinea pigs

    Studies on the effect of Lathyrus Sativus seeds (LLS) on aromatic L-amino acid decarboxylase (AADC) and on dipeptidyl-aminopeptidase-IV (DAP-IV) were carried out in the central and peripheral tissues and serum of LSS-treated and LSS plus vitamin C-treated guinea pigs. The feeding of LSS for 35 days decreased the AADC activity significantly in the brain and peripheral tissues, but the activity was recovered to normal level in the most tissues when vitamin C was added with the LSS. DAP-IV activity decreased in the peripheral tissues when treated with LSS, but the vitamin C administration with LSS did not recover the enzyme activity. The DAP-IV activity did not decrease significantly in any of the brain tissues of the LSS-treated group. (author). 18 refs, 2 tabs

  4. GAD65 antibodies among Greenland Inuit and its relation to glucose intolerance

    Pedersen, Michael Lynge; Bjerregaard, Peter; Jørgensen, Marit Eika

    2014-01-01

    fasting glycemia, (3) with impaired glucose tolerance and (4) with previously unknown diabetes based on oral glucose tolerance test and were enrolled in the study. Presence of circulating Glutamin-Acid-decarboxylase 65 antibodies were measured in all participants. A total of 484 persons were enrolled in...

  5. Substrate Binding Induces Domain Movements in Orotidine 5'-Monophosphate Decarboxylase

    Harris, Pernille Hanne; Poulsen, Jens-Christian Navarro; Jensen, Kaj Frank; Larsen, Sine

    2002-01-01

    Orotidine 5'-monophosphate decarboxylase (ODCase) catalyses the decarboxylation of orotidine 5'-monophosphate to uridine 5'-monophosphate (UMP). We have earlier determined the structure of ODCase from Escherichia coli complexed with the inhibitor 1-(5'-phospho-ß- -ribofuranosyl)barbituric acid (BMP...

  6. Testing the GAD throughout the Precambrian

    Veikkolainen, T.; Pesonen, L. J.; Korhonen, K.

    2013-05-01

    A long tradition has emerged in using the inclination frequency analysis to study the functionality of the Geocentric Axial Dipole (GAD) hypothesis in paleomagnetism. Here a test is presented, based on 3016 records of the Earth's Precambrian geomagnetic field as acquired from a novel catalogue maintained by University of Helsinki, and Yale University. The technique is based on fitting zonal (axial) dipolar (GAD), quadrupolar (G2) and octupolar (G3) harmonics to find the best-fitting inclination distribution. The influence of various factors, such as the geologic age, rock type, magnetic polarity, quality of data and its spatial distribution has been tested. Finally, the most plausible estimates for the zonal non-dipolar contributions of the field have been determined as 0 % for G2 and 6 % for G3. Another way to analyze the zonal harmonics of the geomagnetic field and the validity of GAD is based on the asymmetry between the normal and reversed polarities. To get an insight to the morphology of the field in the late Paleoproterozoic, we have also run a reversal simulation using data mainly from the 1.88 Ga Stark Formation, Canada, revealing the both stable polarity directions (N, R) and also transitional directions between them. In the global Precambrian perspective, an overall moderate dependence of the inclination asymmetry on paleolatitude is visible with a distinct mid-latitude peak. However, the required values to account for the observed deviation from GAD are less than 5 % for G2 and less than 10 % for G3. Alternatively, paleosecular variation (PSV) can be used to shed light to processes in the geodynamo and to model the growth of the inner core. We have applied the CALS3K model of the field as a basis of a time simulation of declination-inclination pairs around a grid on the Earth and by this way in estimating PSV. Our approach is based on calculating S vs latitude curves at different time instances in the validity period of the model, and comparing them

  7. 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.

    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

  8. Distinct neurochemical and functional properties of GAD67-containing 5-HT neurons in the rat dorsal raphe nucleus.

    Shikanai, Hiroki; Yoshida, Takayuki; Konno, Kohtarou; Yamasaki, Miwako; Izumi, Takeshi; Ohmura, Yu; Watanabe, Masahiko; Yoshioka, Mitsuhiro

    2012-10-10

    The serotonergic (5-HTergic) system arising from the dorsal raphe nucleus (DRN) is implicated in various physiological and behavioral processes, including stress responses. The DRN is comprised of several subnuclei, serving specific functions with distinct afferent and efferent connections. Furthermore, subsets of 5-HTergic neurons are known to coexpress other transmitters, including GABA, glutamate, or neuropeptides, thereby generating further heterogeneity. However, despite the growing evidence for functional variations among DRN subnuclei, relatively little is known about how they map onto neurochemical diversity of 5-HTergic neurons. In the present study, we characterized functional properties of GAD67-expressing 5-HTergic neurons (5-HT/GAD67 neurons) in the rat DRN, and compared with those of neurons expressing 5-HTergic molecules (5-HT neurons) or GAD67 alone. While 5-HT/GAD67 neurons were absent in the dorsomedial (DRD) or ventromedial (DRV) parts of the DRN, they were selectively distributed in the lateral wing of the DRN (DRL), constituting 12% of the total DRL neurons. They expressed plasmalemmal GABA transporter 1, but lacked vesicular inhibitory amino acid transporter. By using whole-cell patch-clamp recording, we found that 5-HT/GAD67 neurons had lower input resistance and firing frequency than 5-HT neurons. As revealed by c-Fos immunohistochemistry, neurons in the DRL, particularly 5-HT/GAD67 neurons, showed higher responsiveness to exposure to an open field arena than those in the DRD and DRV. By contrast, exposure to contextual fear conditioning stress showed no such regional differences. These findings indicate that 5-HT/GAD67 neurons constitute a unique neuronal population with distinctive neurochemical and electrophysiological properties and high responsiveness to innocuous stressor. PMID:23055511

  9. Effects of traditionally used anxiolytic botanicals on enzymes of the gamma-aminobutyric acid (GABA) system.

    Awad, R; Levac, D; Cybulska, P; Merali, Z; Trudeau, V L; Arnason, J T

    2007-09-01

    In Canada, the use of botanical natural health products (NHPs) for anxiety disorders is on the rise, and a critical evaluation of their safety and efficacy is required. The purpose of this study was to determine whether commercially available botanicals directly affect the primary brain enzymes responsible for gamma-aminobutyric acid (GABA) metabolism. Anxiolytic plants may interact with either glutamic acid decarboxylase (GAD) or GABA transaminase (GABA-T) and ultimately influence brain GABA levels and neurotransmission. Two in vitro rat brain homogenate assays were developed to determine the inhibitory concentrations (IC50) of aqueous and ethanolic plant extracts. Approximately 70% of all extracts that were tested showed little or no inhibitory effect (IC50 values greater than 1 mg/mL) and are therefore unlikely to affect GABA metabolism as tested. The aqueous extract of Melissa officinalis (lemon balm) exhibited the greatest inhibition of GABA-T activity (IC50 = 0.35 mg/mL). Extracts from Centella asiatica (gotu kola) and Valeriana officinalis (valerian) stimulated GAD activity by over 40% at a dose of 1 mg/mL. On the other hand, both Matricaria recutita (German chamomile) and Humulus lupulus (hops) showed significant inhibition of GAD activity (0.11-0.65 mg/mL). Several of these species may therefore warrant further pharmacological investigation. The relation between enzyme activity and possible in vivo mode of action is discussed. PMID:18066140

  10. vglut2 and gad Expression Reveal Distinct Patterns of Dual GABAergic Versus Glutamatergic Cotransmitter Phenotypes of Dopaminergic and Noradrenergic Neurons in the Zebrafish Brain

    Filippi, Alida; Mueller, Thomas; Driever, Wolfgang

    2014-01-01

    Throughout the vertebrate lineage, dopaminergic neurons form important neuromodulatory systems that influence motor behavior, mood, cognition, and physiology. Studies in mammals have established that dopaminergic neurons often use γ-aminobutyric acid (GABA) or glutamatergic cotransmission during development and physiological function. Here, we analyze vglut2, gad1b and gad2 expression in combination with tyrosine hydroxylase immunoreactivity in 4-day-old larval and 30-day-old juvenile zebrafi...

  11. γ-Amino-butyric acid (GABA) receptor subunit and transporter expression in the gonad and liver of the fathead minnow (Pimephales promelas).

    Biggs, Katie; Seidel, Jason S; Wilson, Alex; Martyniuk, Christopher J

    2013-09-01

    γ-Amino-butyric acid (GABA) is the major inhibitory neurotransmitter in the vertebrate central nervous system. GABA receptors and synthesizing enzymes have also been localized to peripheral tissues including the liver, oviduct, uterus and ovary of mammals but the distribution and role of GABA in peripheral tissues of fish has not been fully investigated. The objectives of this study were to (1) determine if mRNA encoding GABA synthesizing enzymes (glutamic acid decarboxylase 65 and 67; gad65 and gad67), GABA transporters, and GABAA receptor subunits are localized to liver and gonad of fathead minnow (Pimephales promelas) (FHM) (2) investigate the effects of GABA on ovarian 17β-estradiol (E2) production, and (3) measure transcript responses in the ovary after in vitro incubation to GABA. Real-time PCR assays were developed for gad65, gad67, vesicular GABA transporter (vgat) and GABA transporter 1 (gat1), and select GABAA receptor subunits (gabra1, gabra5, gabrb1, gabrb2, gabrg1, gabrg2). All transcripts were localized to the brain as expected; however transcripts were also detected in the liver, ovary, and testis of FHMs. In the female liver, gad65 mRNA was significantly higher in expression compared to the male liver. Transcripts for gad67 were the highest in the brain>gonad>liver and in the gonads, gad67 was significantly higher in expression than gad65 mRNA. In the liver and gonad, the relative abundance of the subunits followed a general trend of gabrb1>gabrb2=gabrg1=gabrg2>gabra1=gabra5. To explore the effects of GABA in the ovary, tissue explants from reproductive female FHMs were treated with GABA (10(-10), 10(-8) and 10(-6)M) for 12h. GABA had no significant effect on 17β-estradiol production or on mRNA abundance for genes involved in ovarian steroidogenesis (e.g., 11βhsd, cyp17, cyp19a). There was a significant decrease in estrogen receptor 2a (esr2a) mRNA with 10(-10)M GABA. This study begins to investigate the GABA system in non-neural tissues of

  12. Comparison of Measurements of Autoantibodies to Glutamic Acid Decarboxylase and Islet Antigen-2 in Whole Blood Eluates from Dried Blood Spots Using the RSR-Enzyme Linked Immunosorbent Assay Kits and In-House Radioimmunoassays

    Anders Persson

    2010-01-01

    Full Text Available To evaluate the performance of dried blood spots (DBSs with subsequent analyses of glutamic acid decarboxylase (GADA and islet antigen-2 (IA-2A with the RSR-ELISAs, we selected 80 children newly diagnosed with type 1 diabetes and 120 healthy women. DBSs from patients and controls were used for RSR-ELISAs while patients samples were analysed also with in-house RIAs. The RSR-ELISA-GADA performed well with a specificity of 100%, albeit sensitivity (46% was lower compared to in RIA (56%; P=.008. No prozone effect was observed after dilution of discrepant samples. RSR-ELISA-IA-2A achieved specificity of 69% and sensitivity was lower (59% compared with RIA (66%; P<.001. Negative or low positive patients and control samples in the RSR-ELISA-IA-2A increased after dilution. Eluates from DBS can readily be used to analyse GADA with the RSR-ELISA, even if low levels of autoantibodies were not detected. Some factor could disturb RSR-ELISA-IA-2A analyses.

  13. 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.

    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

  14. Production of gamma-aminobutyric acid by Streptococcus salivarius subsp. thermophilus Y2 under submerged fermentation.

    Yang, S-Y; Lü, F-X; Lu, Z-X; Bie, X-M; Jiao, Y; Sun, L-J; Yu, B

    2008-04-01

    Gamma-aminobutyric acid (GABA), a major inhibitory neurotransmitter in the central nervous system, has several well-known physiological functions and has been applied to the production of many drugs and functional foods. The technology of GABA production via submerged fermentation by Streptococcus salivarius subsp. thermophilus Y2 was investigated in this paper. It indicated that the GABA production was related to the biochemical characteristics of glutamate decarboxylase (GAD) of S. salivarius subsp. thermophilus Y2. After 24 h of fermentation at 37 degrees C, which is the suitable culture conditions for GAD-production, then the culture condition were adjusted to the optimal temperature (40 degrees C) and pH (4.5) for the GAD reaction activity in biotransformation of cells and pyridoxal 5'-phosphate (0.02 mmol/l) were added to the broth at the 48 h, the GABA production was increased up to 1.76-fold, reaching 7984.75 +/- 293.33 mg/l. The strain shows great potential use as a starter for GABA-containing yoghurt, cheese and other functional fermented food productions. PMID:17514494

  15. Characterization of arginine decarboxylase from Dianthus caryophyllus.

    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

  16. Glutamine, glutamate, and arginine-based acid resistance in Lactobacillus reuteri.

    Teixeira, Januana S; Seeras, Arisha; Sanchez-Maldonado, Alma Fernanda; Zhang, Chonggang; Su, Marcia Shu-Wei; Gänzle, Michael G

    2014-09-01

    This study aimed to determine whether glutamine deamidation improves acid resistance of Lactobacillus reuteri, and to assess whether arginine, glutamine, and glutamate-mediated acid resistance are redundant or complementary mechanisms of acid resistance. Three putative glutaminase genes, gls1, gls2, and gls3, were identified in L. reuteri 100-23. All three genes were expressed during growth in mMRS and wheat sourdough. L. reuteri consistently over-expressed gls3 and the glutamate decarboxylase gadB. L. reuteri 100-23ΔgadB over-expressed gls3 and the arginine deiminase gene adi. Analysis of the survival of L. reuteri in acidic conditions revealed that arginine conversion is effective at pH of 3.5 while glutamine or glutamate conversion were effective at pH of 2.5. Arginine conversion increased the pHin but not ΔΨ; glutamate decarboxylation had only a minor effect on the pHin but increased the ΔΨ. This study demonstrates that glutamine deamidation increases the acid resistance of L. reuteri independent of glutamate decarboxylase activity. Arginine and glutamine/glutamate conversions confer resistance to lactate at pH of 3.5 and phosphate at pH of 2.5, respectively. Knowledge of L. reuteri's acid resistance improves the understanding of the adaptation of L. reuteri to intestinal ecosystems, and facilitates the selection of probiotic and starter cultures. PMID:24929734

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

    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.

  18. GAD65 is essential for synthesis of GABA destined for tonic inhibition regulating epileptiform activity

    Walls, Anne B; Nilsen, Linn Hege; Eyjolfsson, Elvar M; Vestergaard, Henrik T; Hansen, Suzanne L; Schousboe, Arne; Sonnewald, Ursula; Waagepetersen, Helle S

    2010-01-01

    . In contrast, the functional significance of GAD65 in the maintenance of GABA destined for extrasynaptic tonic inhibition is less well studied. Using GAD65-/- and wild type GAD65+/+ mice, this was examined employing the cortical wedge preparation, a model suitable for investigating extrasynaptic GABA...... synthesized by GAD65 was further investigated in vivo. Tonic inhibition and the demand for biosynthesis of GABA were augmented by injection of kainate into GAD65-/- and GAD65+/+ mice. Moreover, [1-(13) C]glucose and [1,2-(13) C]acetate were administered to study neuronal and astrocytic metabolism...

  19. Impact of Precooling and Controlled-Atmosphere Storage on γ-Aminobutyric Acid (GABA) Accumulation in Longan (Dimocarpus longan Lour.) Fruit.

    Zhou, Molin; Ndeurumio, Kessy H; Zhao, Lei; Hu, Zhuoyan

    2016-08-24

    Longan (Dimocarpus longan Lour.) fruit cultivars 'Chuliang' and 'Shixia' were analyzed for γ-aminobutyric acid (GABA) accumulation after precooling and in controlled-atmosphere storage. Fruit were exposed to 5% O2 plus 3%, 5%, or 10% CO2 at 4 °C, and GABA and associated enzymes, aril firmness, and pericarp color were measured. Aril softening and pericarp browning were delayed by 5% CO2 + 5% O2. GABA concentrations and glutamate decarboxylase (GAD; EC 4.1.1.15) activities declined during storage at the higher-CO2 treatments. However, GABA aminotransferase (GABA-T; EC 2.6.1.19) activities in elevated CO2-treated fruit fluctuated during storage. GABA concentrations increased after precooling treatments. GAD activity and GABA-T activity were different between cultivars after precooling. GABA concentrations in fruit increased after 3 days of 10% CO2 + 5% O2 treatment and then declined as storage time increased. GABA accumulation was associated with stimulation of GAD activity rather than inhibition of GABA-T activity. PMID:27412947

  20. Generalized Anxiety Disorder (GAD): When Worry Gets Out of Control

    ... Researchers are also looking for ways in which stress and environmental factors may play a role. How is GAD treated? First, talk to your doctor about your symptoms. Your doctor should do an exam to make sure that another physical problem isn’ ...

  1. A radiometric microassay for ornithine decarboxylase

    A simple method for purifying [3H]L-ornithine and incubation conditions suitable for estimating L-ornithine decarboxylase activity are described. Routine and recycle cation exchange procedures for separating putrescine from ornithine are outlined. Blanks using the routine cation exchange method average approx. 0.04% of the radioactivity contained in the substrate; product recovery is approx. 94%. The L-ornithine decarboxylase assay is proportional to time for at least 8 h. The relationship between substrate purity and the sensitivity of the cation exchange procedures is assessed. Radiochemical purity is the critical determinant of sensitivity for recycled assays. The cation exchange method is compared with the commonly used CO2-trapping method. The cation exchange method is more specific and approximately three orders of magnitude more sensitive than the CO2-trapping method. L-ornithine decarboxylase activity can be measured reliably in samples of embryonic neural tissues having wet-weights of approx. 1 μg. L-ornithine decarboxylase activity in the lumbar spinal cord of the chick embryo decreases 25-30 fold from day 5 to day 18 of embryonic development. A cation exchange procedure for estimating L-lysine decarboxylase activity is also described. Failure to detect L-lysine decarboxylase activity in the chick embryo lumbar spinal cord is contrasted with the previous report of high cadaverine levels in chick embryos. (author)

  2. Glutaminsyre-decarboxylase-antistoffer og diabetes

    Mandrup-Poulsen, Thomas

    2007-01-01

    The 1999 WHO classification delineates immune mediated type 1 diabetes from other types of diabetes by the presence of auto-antibodies against beta-cell constituents. The GAD65 auto-antibody test is the method of first choice because it has the highest sensitivity, specificity and positive...... predictive value and is the most standardized and well-characterized type 1 diabetes related auto-antibody analysis. It is recommended that demonstration of GAD auto-antibodies leads to diagnosis, classification or re-classification of diabetes patients as immune mediated type 1 diabetes. Udgivelsesdato...

  3. Disease-specific monoclonal antibodies targeting glutamate decarboxylase impair GABAergic neurotransmission and affect motor learning and behavioral functions

    Mario U Manto

    2015-03-01

    Full Text Available Autoantibodies to the smaller isoform of glutamate decarboxylase can be found in patients with type 1 diabetes and a number of neurological disorders, including stiff-person syndrome, cerebellar ataxia and limbic encephalitis. The detection of disease-specific autoantibody epitopes led to the hypothesis that distinct glutamate decarboxylase autoantibodies may elicit specific neurological phenotypes. We explored the in vitro/in vivo effects of well-characterized monoclonal glutamate decarboxylase antibodies. We found that glutamate decarboxylase autoantibodies present in patients with stiff person syndrome (n = 7 and cerebellar ataxia (n = 15 recognized an epitope distinct from that recognized by glutamate decarboxylase autoantibodies present in patients with type 1 diabetes mellitus (n = 10 or limbic encephalitis (n = 4. We demonstrated that the administration of a monoclonal glutamate decarboxylase antibody representing this epitope specificity (1 disrupted in vitro the association of glutamate decarboxylase with γ-Aminobutyric acid containing synaptic vesicles, (2 depressed the inhibitory synaptic transmission in cerebellar slices with a gradual time course and a lasting suppressive effect, (3 significantly decreased conditioned eyelid responses evoked in mice, with no modification of learning curves in the classical eyeblink-conditioning task, (4 markedly impaired the facilitatory effect exerted by the premotor cortex over the motor cortex in a paired-pulse stimulation paradigm, and (5 induced decreased exploratory behavior and impaired locomotor function in rats. These findings support the specific targeting of glutamate decarboxylase by its autoantibodies in the pathogenesis of stiff-person syndrome and cerebellar ataxia. Therapies of these disorders based on selective removal of such glutamate decarboxylase antibodies could be envisioned.

  4. Enlargement of Axo-Somatic Contacts Formed by GAD-Immunoreactive Axon Terminals onto Layer V Pyramidal Neurons in the Medial Prefrontal Cortex of Adolescent Female Mice Is Associated with Suppression of Food Restriction-Evoked Hyperactivity and Resilience to Activity-Based Anorexia.

    Chen, Yi-Wen; Wable, Gauri Satish; Chowdhury, Tara Gunkali; Aoki, Chiye

    2016-06-01

    Many, but not all, adolescent female mice that are exposed to a running wheel while food restricted (FR) become excessive wheel runners, choosing to run even during the hours of food availability, to the point of death. This phenomenon is called activity-based anorexia (ABA). We used electron microscopic immunocytochemistry to ask whether individual differences in ABA resilience may correlate with the lengths of axo-somatic contacts made by GABAergic axon terminals onto layer 5 pyramidal neurons (L5P) in the prefrontal cortex. Contact lengths were, on average, 40% greater for the ABA-induced mice, relative to controls. Correspondingly, the proportion of L5P perikaryal plasma membrane contacted by GABAergic terminals was 45% greater for the ABA mice. Contact lengths in the anterior cingulate cortex correlated negatively and strongly with the overall wheel activity after FR (R = -0.87, P < 0.01), whereas those in the prelimbic cortex correlated negatively with wheel running specifically during the hours of food availability of the FR days (R = -0.84, P < 0.05). These negative correlations support the idea that increases in the glutamic acid decarboxylase (GAD) terminal contact lengths onto L5P contribute toward ABA resilience through suppression of wheel running, a behavior that is intrinsically rewarding and helpful for foraging but maladaptive within a cage. PMID:25979087

  5. Purification, crystallization and preliminary X-ray analysis of human histidine decarboxylase

    Human histidine decarboxylase was crystallized by the sitting-drop vapour-diffusion method. Diffraction data were collected to 1.8 Å resolution. The core domain of a human histidine decarboxylase mutant was purified and cocrystallized with the inhibitor l-histidine methyl ester. Using synchrotron radiation, a data set was collected from a single crystal at 100 K to 1.8 Å resolution. The crystal belonged to space group C2, with unit-cell parameters a = 215.16, b = 112.72, c = 171.39 Å, β = 110.3°. Molecular replacement was carried out using the structure of aromatic l-amino-acid decarboxylase as a search model. The crystal contained three dimers per asymmetric unit, with a Matthews coefficient (VM) of 3.01 Å3 Da−1 and an estimated solvent content of 59.1%

  6. Evaluation of improved γ-aminobutyric acid production in yogurt using Lactobacillus plantarum NDC75017.

    Shan, Y; Man, C X; Han, X; Li, L; Guo, Y; Deng, Y; Li, T; Zhang, L W; Jiang, Y J

    2015-04-01

    Most γ-aminobutyric acid (GABA)-producing microorganisms are lactic acid bacteria (LAB), but the yield of GABA is limited in most of these GABA-producing strains. In this study, the production of GABA was carried out by using Lactobacillus plantarum NDC75017, a strain screened from traditional fermented dairy products in China. Concentrations of substrate (l-monosodium glutamate, L-MSG) and coenzyme (pyridoxal-5-phosphate, PLP) of glutamate decarboxylase (GAD) and culture temperature were investigated to evaluate their effects on GABA yield of Lb. plantarum NDC75017. The results indicated that GABA production was related to GAD activity and biomass of Lb. plantarum NDC75017. Response surface methodology was used to optimize conditions of GABA production. The optimal factors for GABA production were L-MSG at 80 mM, PLP at 18 μM, and a culture temperature of 36 °C. Under these conditions, production of GABA was maximized at 314.56 mg/100 g. Addition of Lb. plantarum NDC75017 to a commercial starter culture led to higher GABA production in fermented yogurt. Flavor and texture of the prepared yogurt and the control yogurt did not differ significantly. Thus, Lb. plantarum NDC75017 has good potential for manufacture of GABA-enriched fermented milk products. PMID:25622870

  7. Disease progression and search for monogenic diabetes among children with new onset type 1 diabetes negative for ICA, GAD- and IA-2 Antibodies

    Pörksen, Sven; Laborie, Lene; Nielsen, Lotte;

    2010-01-01

    BACKGROUND:To investigate disease progression the first 12 months after diagnosis in children with type 1 diabetes negative (AAB negative) for pancreatic autoantibodies [islet cell autoantibodies(ICA), glutamic acid decarboxylase antibodies (GADA) and insulinoma-associated antigen-2 antibodies (I...

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

    French, Jarrod B.; Ealick, Steven E. (Cornell)

    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.

  9. Characterization and crystallization of human uroporphyrinogen decarboxylase.

    Phillips, J. D.; Whitby, F. G.; Kushner, J. P.; Hill, C. P.

    1997-01-01

    The cytosolic enzyme uroporphyrinogen decarboxylase (URO-D) catalyzes the fifth step in the heme biosynthetic pathway, converting uroporphyrinogen to coproporphyrinogen by decarboxylating the four acetate side chains of the substrate. Recombinant human URO-D has been expressed in Escherichia coli with a histidine tag and has been purified to homogeneity. Purified protein was determined to be a monodisperse dimer by dynamic light scattering. Equilibrium sedimentation analysis confirmed that th...

  10. Immobilization by Polyurethane of Pseudomonas dacunhae Cells Containing l-Aspartate β-Decarboxylase Activity and Application to l-Alanine Production

    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...

  11. Structures of Bacterial Biosynthetic Arginine Decarboxylases

    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.

  12. Molecular gene cloning and sequencing of glutamate decarboxylase gene from Lactobacillus delbrueckii and Lactobacillus reuteri

    Mahsa Taherzadeh; Abolghasem Esmaeili; Mohammad Rabbani

    2015-01-01

    Glutamate decarboxylase enzyme produces γ-aminobutyric acid (GABA) in a non-reversible decarboxylation reaction of glutamate. GABA is a major inhibitory neurotransmitter of the brain and it is also present at high concentration in other organs such as pancreatic islets. GABA has effects on blood pressure, diabetes, inflammation, sleeplessness and depression. Some bacteria such as Lactobacillus strains are capable of GABA production. Identification of these bacteria is important both for resea...

  13. Cloning, Sequencing, and Disruption of the Bacillus subtilis psd Gene Coding for Phosphatidylserine Decarboxylase

    Matsumoto, Kouji; Okada, Masahiro; Horikoshi, Yuko; Matsuzaki, Hiroshi; Kishi, Tsutomu; Itaya, Mitsuhiro; Shibuya, Isao

    1998-01-01

    The psd gene of Bacillus subtilis Marburg, encoding phosphatidylserine decarboxylase, has been cloned and sequenced. It encodes a polypeptide of 263 amino acid residues (deduced molecular weight of 29,689) and is located just downstream of pss, the structural gene for phosphatidylserine synthase that catalyzes the preceding reaction in phosphatidylethanolamine synthesis (M. Okada, H. Matsuzaki, I. Shibuya, and K. Matsumoto, J. Bacteriol. 176:7456–7461, 1994). Introduction of a plasmid contain...

  14. Sleep-Waking Discharge of Ventral Tuberomammillary Neurons in Wild-Type and Histidine Decarboxylase Knock-Out Mice

    Sakai, Kazuya; Takahashi, Kazumi; Anaclet, Christelle; Lin, Jian-Sheng

    2010-01-01

    Using extracellular single-unit recordings, we have determined the characteristics of neurons in the ventral tuberomammillary nucleus (VTM) of wild-type (WT) and histidine decarboxylase knock-out (HDC-KO) mice during the sleep-waking cycle. The VTM neurons of HDC-KO mice showed no histamine immunoreactivity, but were immunoreactive for the histaminergic (HA) neuron markers adenosine deaminase and glutamic acid decarboxylase 67. In the VTM of WT mice, we found waking (W)-specific, non-W-specif...

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

    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.

  16. Molecular and functional characterization of GAD67-expressing, newborn granule cells in mouse dentate gyrus

    Carolina eCabezas

    2013-04-01

    Full Text Available Dentate gyrus granule cells (GCs have been suggested to synthesize both GABA and glutamate immediately after birth and under pathological conditions in the adult. Expression of the GABA synthesizing enzyme GAD67 by GCs during the first few weeks of postnatal development may then allow for transient GABA synthesis and synaptic release from these cells. Here, using the GAD67-EGFP transgenic strain G42, we explored the phenotype of GAD67-expressing GCs in the mouse dentate gyrus. We report a transient, GAD67-driven EGFP expression in differentiating GCs throughout ontogenesis. EGFP expression correlates with the expression of GAD and molecular markers of GABA release and uptake in 2-4 weeks postmitotic GCs. These rather immature cells are able to fire action potentials and are synaptically integrated in the hippocampal network. Yet they show physiological properties that differentiate them from mature GCs. Finally, GAD67-expressing GCs express a specific complement of GABAA receptor subunits as well as distinctive features of synaptic and tonic GABA signaling. Our results reveal that GAD67 expression in dentate gyrus granule cells is a transient marker of late differentiation that persists throughout life and the G42 strain may be used to visualize newborn GCs at a specific, well-defined differentiation stage.

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

    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

  18. Cloning and Sequence Analysis of the meso-Diaminopimelate Decarboxylase Gene from Bacillus methanolicus MGA3 and Comparison to Other Decarboxylase Genes

    Mills, D. A.; Flickinger, M. C.

    1993-01-01

    The lysA gene of Bacillus methanolicus MGA3 was cloned by complementation of an auxotrophic Escherichia coli lysA22 mutant with a genomic library of B. methanolicus MGA3 chromosomal DNA. Subcloning localized the B. methanolicus MGA3 lysA gene into a 2.3-kb SmaI-SstI fragment. Sequence analysis of the 2.3-kb fragment indicated an open reading frame encoding a protein of 48,223 Da, which was similar to the meso-diaminopimelate (DAP) decarboxylase amino acid sequences of Bacillus subtilis (62%) ...

  19. Gamma-aminobutyric acid (GABA) and neuropeptides in neural areas mediating motion-induced emesis

    Damelio, F.; Daunton, Nancy G.; Fox, Robert A.

    1991-01-01

    Immunocytochemical methods were employed to localize the neurotransmitter amino acid gamma-aminobutyric acid and the neuropeptides substance P and Met-enkephalin in the area postrema (AP), area subpostrema (ASP), nucleus of the tractus solitarius (NTS), dorsal motor nucleus of the vagus nerve (DMNV), and lateral vestibular nucleus (LVN). Glutamic acid decarboxylase immunoreactive (GAD-IR) terminals and fibers were observed in the AP and particularly in the ASP. A gradual decrease in the density of terminals was seen towards the solitary complex. The DMNV revealed irregularly scattered GAD-IR terminals within the neuropil or closely surrounding neuronal cell bodies. The LVN, particularly the dorsal division, showed numerous axon terminals which were mostly localize around large neurons and their proximal dendrites. Substance P immunoreactive (SP-IR) terminals and fibers showed high density in the solitary complex, in particular within the lateral division. The ASP showed medium to low density of SP-IR fibers and terminals. The AP exhibited a small number of fibers and terminals irregularly distributed. The DMNV revealed a high density of SP-IR terminals and fibers that were mainly concentrated in the periphery. Very few terminals were detected in the LVN. Met-enkephalin immunoreactive (Met-Enk-IR) fibers and terminals showed high density and uniform distribution in the DMNV. Scattered terminals and fibers were observed in the AP, ASP, and NTS (particularly the lateral division). The very few fibers were observed in the LVN surrounded the neuronal cell bodies. The present report is part of a study designed to investigate the interaction between neuropeptides and conventional neurotransmitters under conditions producing motion sickness and in the process of sensory-motor adaptation.

  20. vglut2 and gad expression reveal distinct patterns of dual GABAergic versus glutamatergic cotransmitter phenotypes of dopaminergic and noradrenergic neurons in the zebrafish brain.

    Filippi, Alida; Mueller, Thomas; Driever, Wolfgang

    2014-06-15

    Throughout the vertebrate lineage, dopaminergic neurons form important neuromodulatory systems that influence motor behavior, mood, cognition, and physiology. Studies in mammals have established that dopaminergic neurons often use γ-aminobutyric acid (GABA) or glutamatergic cotransmission during development and physiological function. Here, we analyze vglut2, gad1b and gad2 expression in combination with tyrosine hydroxylase immunoreactivity in 4-day-old larval and 30-day-old juvenile zebrafish brains to determine which dopaminergic and noradrenergic groups may use GABA or glutamate as a second transmitter. Our results show that most dopaminergic neurons also express GABAergic markers, including the dopaminergic groups of the olfactory bulb (homologous to mammalian A16) and the subpallium, the hypothalamic groups (A12, A14), the prethalamic zona incerta group (A13), the preoptic groups (A15), and the pretectal group. Thus, the majority of catecholaminergic neurons are gad1b/2-positive and coexpress GABA. A very few gad1/2-negative dopaminergic groups, however, express vglut2 instead and use glutamate as a second transmitter. These glutamatergic dual transmitter phenotypes are the Orthopedia transcription factor-dependent, A11-type dopaminergic neurons of the posterior tuberculum. All together, our results demonstrate that all catecholaminergic groups in zebrafish are either GABAergic or glutamatergic. Thus, cotransmission of dopamine and noradrenaline with either GABA or glutamate appears to be a regular feature of zebrafish catecholaminergic systems. We compare our results with those that have been described for mammalian systems, discuss the phenomenon of transmitter dualism in the context of developmental specification of GABAergic and glutamatergic regions in the brain, and put this phenomenon in an evolutionary perspective. PMID:24374659

  1. Perturbation of the Monomer-Monomer Interfaces of the Benzoylformate Decarboxylase Tetramer

    Andrews, Forest H.; Rogers, Megan P.; Paul, Lake N.; McLeish, Michael J. [IUPUI; (Purdue)

    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.

  2. Keto-isovalerate decarboxylase enzymes and methods of use thereof

    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.

  3. GAD67-mediated GABA Synthesis and Signaling Regulate Inhibitory Synaptic Innervation in the Visual Cortex

    Chattopadhyaya, Bidisha; Di Cristo, Graziella; Wu, Cai Zhi; Knott, Graham; Kuhlman, Sandra; Fu, Yu; Palmiter, Richard D.; Huang, Z. Josh

    2007-01-01

    The development of GABAergic inhibitory circuits is shaped by neural activity, but the underlying mechanisms are unclear. we demonstrate a novel function of GABA in regulating GABAergic innervation in the adolescent brain, when GABA is mainly known as an inhibitory transmitter. Conditional knockdown of the rate-limiting synthetic enzyme GAD67 in basket interneurons in adolescent visual cortex resulted in cell autonomous deficits in axon branching, perisomatic synapse formation around pyramidal neurons, and complexity of the innervation fields; the same manipulation had little influence on the subsequent maintenance of perisomatic synapses. These effects of GABA deficiency were rescued by suppressing GABA re-uptake and by GABA receptor agonists. Germ-line knockdown of GAD67 but not GAD65 showed similar deficits, suggesting a specific role of GAD67 in the maturation of perisomatic innervation. Since intracellular GABA levels are modulated by neuronal activity, our results implicate GAD67-mediated GABA synthesis in activity-dependent regulation of inhibitory innervation patterns. PMID:17582330

  4. Prevalence and Regional Distribution of Autoantibodies Against GAD65Ab in a European Population Without Diabetes

    Rolandsson, Olov; Hampe, Christiane S; Wennberg, Patrik; Radtke, Jared; Langenberg, Claudia; Wareham, Nicholas

    2015-01-01

    Geographical differences in type 1 diabetes (T1D) prevalence in Europe have been well documented, but little is known about the geographical distribution of autoantibodies specific to GAD65 (GAD65Ab) in the general population without diabetes, which is reported to range between 0.4 and 3%. However......, these studies used different methods to define GAD65Ab positivity with cutoff values based on the 97–99th centile or at +3 SD above the mean among healthy individuals without T1D or type 2 diabetes (T2D). In doing so, the prevalence of GAD65Ab among the study cohorts was, by definition, 1–3%. The...... European countries and 2) compare characteristics of age, sex, and BMI in relation to GAD65Ab positivity. A center-stratified random subcohort of 16,835 (4.9%) individuals was selected from the original European Prospective Investigation into Cancer and Nutrition (EPIC)-InterAct study (1). After exclusion...

  5. [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].

    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

  6. Oxalate-Degrading Activity in Bifidobacterium animalis subsp. lactis: Impact of Acidic Conditions on the Transcriptional Levels of the Oxalyl Coenzyme A (CoA) Decarboxylase and Formyl-CoA Transferase Genes ▿

    Turroni, Silvia; Bendazzoli, Claudia; Dipalo, Samuele C. F.; Candela, Marco; Vitali, Beatrice; Gotti, Roberto; Brigidi, Patrizia

    2010-01-01

    Oxalic acid occurs extensively in nature and plays diverse roles, especially in pathological processes. Due to its highly oxidizing effects, hyperabsorption or abnormal synthesis of oxalate can cause serious acute disorders in mammals and can be lethal in extreme cases. Intestinal oxalate-degrading bacteria could therefore be pivotal in maintaining oxalate homeostasis and reducing the risk of kidney stone development. In this study, the oxalate-degrading activities of 14 bifidobacterial strai...

  7. Studies of the mechanism of benzoylformate decarboxylase

    pH profiles and 13C and D2O solvent isotope effects have been used to study the mechanism of benzoylformate decarboxylase (BFD), which catalyzes the thiamine-PP (TPP) dependent decarboxylation of benzoylformate (BF) to benzaldehyde and CO2. V/K profiles for BF are bell-shaped with pK's of 5.2 and 8.5 in H2O and 6.2 and 9.1 in D2O, with a D2O solvent isotope effect of 6. The pK/sub i/ profile for the competitive inhibitor R-mandelate is also bell-shaped with pK's of 5.3 and 8.2. BF thus appears not to be sticky and to bind only to enzyme in the correct protonation state for reaction (pK's in the V profile are displaced outwards by at least a pH unit and the D2O solvent isotope effect is 2.5). 13C isotope effects were 1.0080 in H2O and 1.0054 in D2O and pH(D) independent. These data suggest that at low BF, formation of the initial tetrahedral intermediate between TPP and BF, and decarboxylation are both partly rate limiting, while at saturating BF, protonation of the enolamine formed after decarboxylation is rate limiting

  8. Cysteinesulfinate decarboxylase: Characterization, inhibition, and metabolic role in taurine formation

    Cysteinesulfinate decarboxylase, an enzyme that plays a major role in the formation of taurine from cysteine, has been purified from rat liver to homogeneity and characterized. The physical properties of the enzyme were studied, along with its substrate specificity. Multiple forms of the enzyme were found in rat liver, kidney, and brain with isoelectric points ranging from pH 5.6 to 4.9. These multiple forms did not differ in their substrate specificity. It was found by using gel electrofocusing and polyclonal antibodies raised to the liver enzyme that the different forms of cysteinesulfinate decarboxylase are identical in the various rat tissues studied. Various inhibitors of the enzyme were tested both in vitro and in vivo in order to evaluate the role of cysteinesulfinate decarboxylase in taurine formation in mammalian tissues. In in vitro studies, cysteinesulfinate decarboxylase was irreversibly inhibited by β-ethylidene-DL-aspartate (Ki = 10 mM), and competitive inhibition was found using mercaptomethylsuccinate (Ki = 0.1 mM) and D-cysteinesulfinate (Ki = 0.32 mM) when L-cysteinesulfinate was used as a substrate. In order to be able to test these inhibitors in vivo, L-[1-14C]cysteinesulfonate was evaluated as a probe for the in vivo measurement of cysteinesulfinate decarboxylase activity. The metabolism of cysteinesulfonate and the product of its transamination, β-sulfopyruvate, was studied, and it was found that L-[1-14C]cysteinesulfonate is an accurate and convenient probe for cysteinesulfinate decarboxylase activity. Using L-[1-14C]cysteinesulfonate, it was found that D-cysteinesulfinate inhibits cysteinesulfinate decarboxylase activity by greater than 90% in the intact mouse and that inhibition lasts for up to fifteen hours

  9. Effects of down-regulating ornithine decarboxylase upon putrescine-associated metabolism and growth in Nicotiana tabacum L.

    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

  10. Interactive effects of glutamine and gamma-aminobutyric acid on growth performance and skeletal muscle amino acid metabolism of 22-42-day-old broilers exposed to hot environment.

    Hu, Hong; Bai, Xi; Shah, Assar Ali; Dai, Sifa; Wang, Like; Hua, Jinling; Che, Chuanyan; He, Shaojun; Wen, Aiyou; Jiang, Jinpeng

    2016-06-01

    The present experiment was conducted to investigate the interactive effects between dietary glutamine (Gln, 0 and 5 g/kg) and gamma-aminobutyric acid (GABA, 0 and 100 mg/kg) on growth performance and amino acid (AA) metabolism of broilers under hot environment. A total of 360 22-day-old Arbor Acres male chickens were randomly assigned to five treatment groups under thermoneutral chamber (PC, 23 °C) and cyclic heat stress (HS, 30-34 °C cycling) conditions. Compared with the PC group, cyclic HS decreased (P consumption (DFC), the concentrations of Gln, glutamate (Glu), and GABA, and the activities of glutaminase and glutamic acid decarboxylase (GAD) in breast muscle at 28, 35, and 42 days, while it increased (P < 0.05) the activities of glutamine synthetase (GS) and gamma-aminobutyric acid transaminase (GABA-T) at 28, 35, and 42 days. Dietary Gln and GABA improved (P < 0.05) DWG and DFC of broilers under cyclic HS during 28-42 days. In breast muscle, the Gln supplementation increased (P < 0.05) the concentrations of Gln (28, 35, and 42 days), Glu (28, 35, and 42 days), and GABA (42 days) and the activities of glutaminase (28, 35, and 42 days) and GAD (28, 35, and 42 days) but decreased (P < 0.05) GS activities at 28, 35, and 42 days and GABA-T activities at 28 days. The addition of GABA increased (P < 0.05) the concentrations of Gln and Glu and activities of glutaminase and GAD, while it decreased (P < 0.05) GABA-T activities at 28, 35, and 42 days. Significant interactions (P < 0.05) between Gln and GABA were found on breast skeletal muscle Gln concentrations, glutaminase activities, GS activities at 28 and 35 days, and DWG, GABA concentrations, and GABA-T activities at 28, 35, and 42 days in broilers under cyclic HS. In conclusion, the present results indicated that the interactions of exogenous Gln and GABA could offer a potential nutritional strategy to prevent HS-related depression in skeletal muscle Gln and GABA

  11. A coenzyme-independent decarboxylase/oxygenase cascade for the efficient synthesis of vanillin.

    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

  12. Ornithine Decarboxylase, Polyamines, and Pyrrolizidine Alkaloids in Senecio and Crotalaria

    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

  13. Diasporicità sull’esempio di Erich Auerbach in Gad Lerner e Miro Silvera

    Jansen, M.M.; Arts, Clemens

    2011-01-01

    A partire dall’esilio di Erich Auerbach a Istanbul dal 1936 al 1947, il contributo propone una riflessione sui concetti di diaspora e di esilio da adattare a due scrittori italo‐ebrei provenienti dalla diaspora orientale: Miro Silvera con Il passeggero occidentale (2009) e Gad Lerner con Scintille (

  14. Role of ornithine decarboxylase in breast cancer

    Wensheng Deng; Xian Jiang; Yu Mei; Jingzhong Sun; Rong Ma; Xianxi Liu; Hui Sun; Hui Tian; Xueying Sun

    2008-01-01

    Ornithine decarboxylase (ODC), the rate-limiting enzyme in polyamine biosynthesis that decarboxylates ornithine to putrescine, has become a promising target for cancer research. The aim of this study is to investigate the role of ODC in breast cancer. We detected expression of ODC in breast cancer tissues and four breast cancer cell lines, and transfected breast cancer cells with an adenoviral vector carrying antisense ODC (rAd-ODC/Ex3as) and examined their growth and migration.ODC was overexpressed in breast cancer tissues and cell lines compared with non-tumor tissues and normal breast epithelial celis,and there was a positive correlation between the level of ODC mRNA and the staging of tumors.The expression of ODC correlated with cyclin D1,a cell cycle protein,in synchronized breast cancer MDA-MB-231 cells.Gene transfection of rAd-ODC/Ex3as markedly down-regulated expression Of ODC and cyclin D1,resulting in suppression of proliferation and cell cycle arrest at G0-G1 phase,and the inhibifion of colony formation,an anchorage-independent growth pattern,and the migratory ability of MDA-MB-231 cells.rAd-ODC/Ex3as also markedly reduced the concentration of putrescine,but not spermidine or spermine,in MDA-MB-231 cells.The results suggested that the ODC gene might act as aprognostic factor for breast cancer and it could be a promising therapeutic target.

  15. Three ways to test the validity of the Geocentric Axial Dipole (GAD) hypothesis in the Precambrian

    Veikkolainen, T.; Pesonen, L. J.; Korhonen, K.

    2012-12-01

    One of the most fundamental aspects of paleomagnetism is the assumption that the temporal mean of the geomagnetic field is indistinguishable from a field generated by a geocentric axial dipole (GAD hypothesis). When the theory became mainstream, various ways to test its functionality were presented, based on e.g. deep-sea sediment cores, paleoclimatic indicators and paleointensity. Most suspicion of the dipolar nature of the geomagnetic field has dealt with the Precambrian. To analyze this bias, we have used the data from the novel paleomagnetic database, collected by University of Helsinki, and Yale University for over a decade's time. Altogether 3016 observations from all major Precambrian continents were gathered, and a thorough compilation of reversals of the Archean and Proterozoic geomagnetic field was done. Observations were filtered using different criteria, e.g. geologic age, rock type (igneous vs. metamorphic vs. sedimentary) and reliability according to the modified Voo-grading. Testing the GAD has rested on a) inclination frequency analysis, b) asymmetries in reversal data, and c) paleosecular variation (PSV) using CALS7K, CALS3K, GUFM and IGRF models as references. The results suggest that the geomagnetic field of the Precambrian is not far from the field predicted by the GAD model. The inclination frequency analysis supports the existence of a small octupolar (ca. 6 % of GAD) component and a quadrupole of 0-8 % of GAD as evaluated using chi-square testing. Conclusions drawn from the asymmetry analysis and PSV are statistically indifferent from this. The deviation from the GAD is smallest for the highest-quality observations, especially so called key poles. They have well-defined isotopic ages, small error parameters in their Fisher data and their primary remanent magnetization has been properly isolated. This also means that the observed functionality of GAD cannot be a misconception caused by secondary magnetizations acquired in the Phanerozoic

  16. Pyruvate decarboxylases from the petite-negative yeast Saccharomyces kluyveri

    Møller, Kasper; Langkjær, Rikke Breinhold; Nielsen, Jens; Piskur, Jure; Olsson, Lisbeth

    2004-01-01

    Saccharomyces kluyveri is a petite-negative yeast, which is less prone to form ethanol under aerobic conditions than is S. cerevisiae. The first reaction on the route from pyruvate to ethanol is catalysed by pyruvate decarboxylase, and the differences observed between S. kluyveri and S. cerevisiae...... with respect to ethanol formation under aerobic conditions could be caused by differences in the regulation of this enzyme activity. We have identified and cloned three genes encoding functional pyruvate decarboxylase enzymes ( PDC genes) from the type strain of S. kluyveri (Sk-PDC11, Sk-PDC12 and Sk...... activity was controlled by variations in the amount of mRNA. The mRNA level and the pyruvate decarboxylase activity responded to anaerobiosis and growth on different carbon sources in essentially the same fashion as in S. cerevisiae. This indicates that the difference in ethanol formation between these two...

  17. Crystal Structure and Substrate Specificity of Drosophila 3,4-Dihydroxyphenylalanine Decarboxylase

    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.

  18. Altered subcellular localization of ornithine decarboxylase in Alzheimer's disease brain

    Nilsson, Tatjana; Bogdanovic, Nenad; Volkman, Inga;

    2006-01-01

    The amyloid precursor protein can through ligand-mimicking induce expression of ornithine decarboxylase (ODC), the initial and rate-limiting enzyme in polyamine biosynthesis. We report here the regional distribution and cellular localization of ODC immunoreactivity in Alzheimer's disease (AD...

  19. Immobilization by Polyurethane of Pseudomonas dacunhae Cells Containing l-Aspartate β-Decarboxylase Activity and Application to l-Alanine Production

    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

  20. Defense of GAD during the 1950s and early 1960s

    Frankel, H. R.

    2012-12-01

    Paleomagnetists favoring continental offered empirical and theoretical support for the GAD hypothesis. Initial support came from the discovery that the mean directions of rock units, regardless of polarity, laid down back through the Upper Tertiary centered on the rotational pole. Armed with Fisher's statistics, Hospers (1951, 1953) found that the mean direction of the NRM of Icelandic lava flows back through the Miocene better agreed with the GAD field than with the present field. Similarly, Campbell and Runcorn (1956), Creer (1956), and Irving and Green (1957) respectively found that the natural remanent magnetization of Late Tertiary Columbia River basalts, Quaternary basalts of Argentina, and Late Cenozoic New Volcanics of Victoria supported the hypothesis. If significant continental drift or "true" polar wander has occurred, paleomagnetic data alone cannot determine if the axial element of the GAD hypothesis holds earlier than Late Tertiary. Extending the GAD hypothesis back in time requires an approach involving a means independent of paleomagnetism for determining past latitudes. Irving was the first to realize that the paleoclimatology would work. If the GAD hypothesis holds, then paleolatitudes based on paleomagnetism and paleoclimatology should agree. Irving (1956) found that, except for the Squantum Tillite, the paleomagnetically and paleoclimatically determined paleolatitudes for Europe, North America, India, and Tasmania were in agreement. He concluded that the magnetic and rotational axes have coincided since the Paleozoic. Blackett (1961) also compared paleoclimatic and paleomagnetic data-sets. Irving and Briden (1962, 1964) further appealed to paleoclimatology to defend the hypothesis. Determining the paleolatitude spectra for several paleoclimatic indicators, they found the present latitude of fossil instances inconsistent with the latitude of modern instances while their paleomagnetically determined paleolatitudes, which assumed the GAD hypothesis

  1. GAD65 haplodeficiency conveys resilience in animal models of stress-induced psychopathology

    Iris eMüller

    2014-08-01

    Full Text Available GABAergic mechanisms are critically involved in the control of fear and anxiety, but their role in the development of stress-induced psychopathologies, including post-traumatic stress disorder (PTSD and mood disorders is not sufficiently understood. We studied these functions in two established mouse models of risk factors for stress-induced psychopathologies employing variable juvenile stress and/or social isolation. A battery of emotional tests in adulthood revealed the induction of contextually generalized fear, anxiety, hyperarousal and depression-like symptoms in these paradigms. These reflect the multitude and complexity of stress effects in human PTSD patients. With factor analysis we were able to identify parameters that reflect these different behavioral domains in stressed animals and thus provide a basis for an integrated scoring of affectedness more closely resembling the clinical situation than isolated parameters. To test the applicability of these models to genetic approaches we further tested the role of GABA using heterozygous mice with targeted mutation of the GABA synthesizing enzyme GAD65 (GAD65+/- mice, which show a delayed postnatal increase in tissue GABA content in limbic and cortical brain areas. Unexpectedly, GAD65(+/- mice did not show changes in exploratory activity regardless of the stressor type and were after the variable juvenile stress procedure protected from the development of contextual generalization in an auditory fear conditioning experiment. Our data demonstrate the complex nature of behavioral alterations in rodent models of stress-related psychopathologies and suggest that GAD65 haplodeficiency, likely through its effect on the postnatal maturation of GABAergic transmission, conveys resilience to some of these stress-induced effects.

  2. GAD67-mediated GABA Synthesis and Signaling Regulate Inhibitory Synaptic Innervation in the Visual Cortex

    Chattopadhyaya, Bidisha; Di Cristo, Graziella; Wu, Cai Zhi; Knott, Graham; Kuhlman, Sandra; Fu, Yu; Palmiter, Richard D; Huang, Z. Josh

    2007-01-01

    The development of GABAergic inhibitory circuits is shaped by neural activity, but the underlying mechanisms are unclear. we demonstrate a novel function of GABA in regulating GABAergic innervation in the adolescent brain, when GABA is mainly known as an inhibitory transmitter. Conditional knockdown of the rate-limiting synthetic enzyme GAD67 in basket interneurons in adolescent visual cortex resulted in cell autonomous deficits in axon branching, perisomatic synapse formation around pyramida...

  3. Sbi00515, a Protein of Unknown Function from Streptomyces bingchenggensis, Highlights the Functional Versatility of the Acetoacetate Decarboxylase Scaffold.

    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

  4. Bacterial Lysine Decarboxylase Influences Human Dental Biofilm Lysine Content, Biofilm Accumulation and Sub-Clinical Gingival Inflammation

    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

  5. COOH-Terminal Clustering of Autoantibody and T-Cell Determinants on the Structure of GAD65 Provide Insights Into the Molecular Basis of Autoreactivity

    Fenalti, Gustavo; Hampe, Christiane S.; Arafat, Yasir; Law, Ruby H.P.; Banga, J. Paul; Mackay, Ian R.; Whisstock, James C.; Buckle, Ashley M.; Rowley, Merrill J. (UWASH); (King’s College); (Monash)

    2008-11-19

    To gain structural insights into the autoantigenic properties of GAD65 in type 1 diabetes, we analyzed experimental epitope mapping data in the context of the recently determined crystal structures of GAD65 and GAD67, to allow 'molecular positioning' of epitope sites for B- and T-cell reactivity. Data were assembled from analysis of reported effects of mutagenesis of GAD65 on its reactivity with a panel of 11 human monoclonal antibodies (mAbs), supplemented by use of recombinant Fab to cross-inhibit reactivity with GAD65 by radioimmunoprecipitation of the same mAbs. COOH-terminal region on GAD65 was the major autoantigenic site. B-cell epitopes were distributed within two separate clusters around different faces of the COOH-terminal domain. Inclusion of epitope sites in the pyridoxal phosphate- and NH{sub 2}-terminal domains was attributed to the juxtaposition of all three domains in the crystal structure. Epitope preferences of different mAbs to GAD65 aligned with different clinical expressions of type 1 diabetes. Epitopes for four of five known reactive T-cell sequences restricted by HLA DRB1*0401 were aligned to solvent-exposed regions of the GAD65 structure and colocalized within the two B-cell epitope clusters. The continuous COOH-terminal epitope region of GAD65 was structurally highly flexible and therefore differed markedly from the equivalent region of GAD67. Structural features could explain the differing antigenicity, and perhaps immunogenicity, of GAD65 versus GAD67. The proximity of B- and T-cell epitopes within the GAD65 structure suggests that antigen-antibody complexes may influence antigen processing by accessory cells and thereby T-cell reactivity.

  6. Chloroform induction of ornithine decarboxylase activity in rats.

    Savage, R E; Westrich, C; Guion, C; M. A. PEREIRA

    1982-01-01

    Chloroform is a drinking water contaminant that has been demonstrated to be carcinogenic to mice and rats resulting in an increased incidence of liver and kidney tumors, respectively. The mechanism of chloroform carcinogenicity might be by tumor initiation and/or promotion. Since induction of ornithine decarboxylase (ODC) activity has been proposed as a molecular marker for tumor promoters, we have investigated the effect of chloroform on ODC activity in rats. Chloroform induced a dose-depend...

  7. Adaptive mutations in sugar metabolism restore growth on glucose in a pyruvate decarboxylase negative yeast strain

    Zhang, Yiming; Liu, Guodong; Engqvist, Martin K. M.;

    2015-01-01

    carbon source, and requires supplementation of C2 compounds to the medium in order to meet the requirement for cytosolic acetyl-CoA for biosynthesis of fatty acids and ergosterol. Results: In this study, a Pdc negative strain was adaptively evolved for improved growth in glucose medium via serial......Background: A Saccharomyces cerevisiae strain carrying deletions in all three pyruvate decarboxylase (PDC) genes (also called Pdc negative yeast) represents a non-ethanol producing platform strain for the production of pyruvate derived biochemicals. However, it cannot grow on glucose as the sole...... transfer, resulting in three independently evolved strains, which were able to grow in minimal medium containing glucose as the sole carbon source at the maximum specific rates of 0.138, 0.148, 0.141 h-1, respectively. Several genetic changes were identified in the evolved Pdc negative strains by genomic...

  8. Arabidopsis Serine Decarboxylase Mutants Implicate the Roles of Ethanolamine in Plant Growth and Development

    Byeong-ha Lee; Hyoungseok Lee; Joung Han Yim; Jian-Kang Zhu; Si-in Yu; Yerim Kwon

    2012-01-01

    Ethanolamine is important for synthesis of choline, phosphatidylethanolamine (PE) and phosphatidylcholine (PC) in plants. The latter two phospholipids are the major phospholipids in eukaryotic membranes. In plants, ethanolamine is mainly synthesized directly from serine by serine decarboxylase. Serine decarboxylase is unique to plants and was previously shown to have highly specific activity to l-serine. While serine decarboxylase was biochemically characterized, its functions and importance ...

  9. Clinical significance of GAD-Ab in patets with type Ⅱ diabetes%Ⅱ型糖尿病患者血清中GAD-Ab测定的临床意义

    叶秀兰; 于瑞萍; 周荣霞; 莫晓虹; 王亚林; 邓小林; 黄山

    2000-01-01

    目的通过谷氨酸脱羧酶抗体(GAD-Ab)测定,了解成人迟发性自身免疫性糖尿病(LA-DA)在Ⅱ型糖尿病中的发病率,以及LADA的一些临床特点.方法对91例诊断为Ⅱ型糖尿病患者及28例正常对照组用ELISA法检测血清中GAD-Ab.结果GAD-Ab阳性率17.58%,高于对照组的0%;且GAD-Ab阳性患者具有低体重指数(BMI)≤21kg/m2,低C肽分泌,酮症史,胰岛素用量偏大的临床特点;而起病年龄、病程及男女比例与阴性无显著差异.结论LADA在Ⅱ型糖尿病中比例较高;Ⅱ型糖尿病中低BMI,低C肽分泌,酮症史,胰岛素用量偏大是LADA诊断的重要线索;GAD-Ab检测对早期诊断LADA有实验价值.

  10. Arabidopsis Serine Decarboxylase Mutants Implicate the Roles of Ethanolamine in Plant Growth and Development

    Byeong-ha Lee

    2012-03-01

    Full Text Available Ethanolamine is important for synthesis of choline, phosphatidylethanolamine (PE and phosphatidylcholine (PC in plants. The latter two phospholipids are the major phospholipids in eukaryotic membranes. In plants, ethanolamine is mainly synthesized directly from serine by serine decarboxylase. Serine decarboxylase is unique to plants and was previously shown to have highly specific activity to L-serine. While serine decarboxylase was biochemically characterized, its functions and importance in plants were not biologically elucidated due to the lack of serine decarboxylase mutants. Here we characterized an Arabidopsis mutant defective in serine decarboxylase, named atsdc-1 (Arabidopsis thaliana serine decarboxylase-1. The atsdc-1 mutants showed necrotic lesions in leaves, multiple inflorescences, sterility in flower, and early flowering in short day conditions. These defects were rescued by ethanolamine application to atsdc-1, suggesting the roles of ethanolamine as well as serine decarboxylase in plant development. In addition, molecular analysis of serine decarboxylase suggests that Arabidopsis serine decarboxylase is cytosol-localized and expressed in all tissue.

  11. Inhibition of parvalbumin-expressing interneurons results in complex behavioral changes

    Brown, Jacquelyn A.; Ramikie, Teniel S.; Schmidt, Martin J.; Báldi, Rita; Garbett, Krassimira; Everheart, Monika G.; Warren, Lambert E.; Gellért, Levente; Horváth, Szatmár; Patel, Sachin; Mirnics, Károly

    2015-01-01

    Reduced expression of the GAD1 gene-encoded 67-kD protein isoform of glutamic acid decarboxylase (GAD67) is a hallmark of the schizophrenia. GAD67 downregulation occurs in multiple interneuronal subpopulations, including the parvalbumin positive (PVALB+) cells. To investigate the role of the PV-positive GABA-ergic interneurons in behavioral and molecular processes, we knocked down the Gad1 transcript using a miRNA engineered to specifically target Gad1 mRNA under the control of Pvalb bacteria...

  12. Gads-deficient thymocytes are blocked at the transitional single positive CD4+ stage

    Dalheimer, Stacy L.; Zeng, Ling; Draves, Kevin E.; Hassaballa, Ashraf; Jiwa, Nasheena N.; Parrish, Torrey D.; Edward A Clark; Yankee, Thomas M.

    2009-01-01

    Positive selection of T cell precursors is the process by which a diverse T cell repertoire is established. Positive selection begins at the CD4+CD8+ double positive (DP) stage of development and involves at least two steps. First, DP thymocytes downregulate CD8 to become transitional single positive (TSP) CD4+ thymocytes. Then, cells are selected to become either mature SP CD4+ or mature SP CD8+ thymocytes. We sought to define the function of Gads during the two steps of positive selection b...

  13. Cognitive Control and Anxiety Disorders: Metacognitive Beliefs and Strategies of Control Thought in GAD and OCD

    Miguel Ángel Pérez Nieto; Marta Mª Redondo Delgado; Leticia León Mateos; Nereida Bueno

    2010-01-01

    En el presente trabajo se asume la relevancia que los procesos de control cognitivo pueden tener en trastornos de ansiedad como el GAD o el TOC. Se pretende identificar las creencias metacognitivas derivadas del modelo S-REF (Wells y Mathews, 1996, Wells, 2000) que se vincularán en mayor medida al espectro del trastorno de ansiedad generalizada y del trastorno obsesivo-compulsivo y el efecto que dichas creencias pueden tener en el uso de estrategias de control cognitivo. Para ello, una muestr...

  14. The philosophy of language in Gadādhara's Śaktivāda

    GANERI, Jonardon

    1993-01-01

    This thesis is a study of the theory of meaning developed by the seventeenth century Indian Naiyāyika philosopher Gadādhara Bhaṭṭācārya. It has four chapters and an appendix. In chapter 1, I highlight some of the problems about meaning and reference thematised by the Indian philosophical tradition during its 'classical' period (third century B.C.E. to seventh century C.E). The work of the earliest grammarians proved very influential We tend to associate the name of the grammar...

  15. Gads (Grb2-related adaptor downstream of Shc) is required for BCR-ABL-mediated lymphoid leukemia

    Gillis, LC; Berry, DM; Minden, MD; McGlade, CJ; Barber, DL

    2016-01-01

    Philadelphia chromosome-positive leukemias, including chronic myeloid leukemia and B-cell acute lymphoblastic leukemia (B-ALL), are driven by the oncogenic BCR-ABL fusion protein. Animal modeling experiments utilizing retroviral transduction and subsequent bone marrow transplantation have demonstrated that BCR-ABL generates both myeloid and lymphoid disease in mice receiving whole bone marrow transduced with BCR-ABL. Y177 of BCR-ABL is critical to the development of myeloid disease, and phosphorylation of Y177 has been shown to induce GRB2 binding to BCR-ABL, followed by activation of the Ras and phosphoinositide 3 kinase signaling pathways. We show that the GRB2-related adapter protein, GADS, also associates with BCR-ABL, specifically through Y177 and demonstrate that BCR-ABL-driven lymphoid disease requires Gads. BCR-ABL transduction of Gads(−/−) bone marrow results in short latency myeloid disease within 3–4 weeks of transplant, while wild-type mice succumb to both a longer latency lymphoid and myeloid diseases. We report that GADS mediates a unique BCR-ABL complex with SLP-76 in BCR-ABL-positive cell lines and B-ALL patient samples. These data suggest that GADS mediates lymphoid disease downstream of BCR-ABL through the recruitment of specific signaling intermediates. PMID:23399893

  16. Pantothenic acid biosynthesis in zymomonas

    Tao, Luan; Tomb, Jean-Francois; Viitanen, Paul V.

    2014-07-01

    Zymomonas is unable to synthesize pantothenic acid and requires this essential vitamin in growth medium. Zymomonas strains transformed with an operon for expression of 2-dehydropantoate reductase and aspartate 1-decarboxylase were able to grow in medium lacking pantothenic acid. These strains may be used for ethanol production without pantothenic acid supplementation in seed culture and fermentation media.

  17. Correlation between arginine decarboxylase expression during abiotic stress and polyamine content in Withania somnifera

    Neha G. Wasnik

    2011-01-01

    Full Text Available Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} (Abstract selected from presentation in National Conference on Biodiversity of Medicinal and Aromatic Plants: Collection, Characterization and Utilization, held at Anand, India during November 24-25, 2010   In plants, polyamines are generally synthesized by the ornithine decarboxylase and arginine decarboxylase (ADC through polyamine pathway. In the current study, attempt was made to clone and characterize a gene encoding arginine decarboxylase from Withania somnifera. A full-length ADC cDNA (WsADC with the longest open reading frame of 828 nucleotides, encoding a 275 amino acids polypeptide was developed by primer walking. WsADC mRNA was expressed in organs such as flower when tested for different plant organs like leaf, root, callus, stem and whole plantlet. Expression level of WsADC in different tissues of ashwagandha was spatially regulated. Transcripts of WsADC in ashwgandha shoots were induced either transiently in response to various abiotc stresses. Treatment of ashwgandha shoots on chilling and wounding remarkably induced accumulation of WsADC mRNA whereas UV light down- regulated the mRNA expression levels. This is the first direct evidence of a function of polyamines in the chilling, wounding

  18. Structural insights into the Escherichia coli lysine decarboxylases and molecular determinants of interaction with the AAA+ ATPase RavA

    Kandiah, Eaazhisai; Carriel, Diego; Perard, Julien; Malet, Hélène; Bacia, Maria; Liu, Kaiyin; Chan, Sze W. S.; Houry, Walid A.; Ollagnier de Choudens, Sandrine; Elsen, Sylvie; Gutsche, Irina

    2016-01-01

    The inducible lysine decarboxylase LdcI is an important enterobacterial acid stress response enzyme whereas LdcC is its close paralogue thought to play mainly a metabolic role. A unique macromolecular cage formed by two decamers of the Escherichia coli LdcI and five hexamers of the AAA+ ATPase RavA was shown to counteract acid stress under starvation. Previously, we proposed a pseudoatomic model of the LdcI-RavA cage based on its cryo-electron microscopy map and crystal structures of an inactive LdcI decamer and a RavA monomer. We now present cryo-electron microscopy 3D reconstructions of the E. coli LdcI and LdcC, and an improved map of the LdcI bound to the LARA domain of RavA, at pH optimal for their enzymatic activity. Comparison with each other and with available structures uncovers differences between LdcI and LdcC explaining why only the acid stress response enzyme is capable of binding RavA. We identify interdomain movements associated with the pH-dependent enzyme activation and with the RavA binding. Multiple sequence alignment coupled to a phylogenetic analysis reveals that certain enterobacteria exert evolutionary pressure on the lysine decarboxylase towards the cage-like assembly with RavA, implying that this complex may have an important function under particular stress conditions. PMID:27080013

  19. Cognitive Control and Anxiety Disorders: Metacognitive Beliefs and Strategies of Control Thought in GAD and OCD

    Miguel Ángel Pérez Nieto

    2010-01-01

    Full Text Available En el presente trabajo se asume la relevancia que los procesos de control cognitivo pueden tener en trastornos de ansiedad como el GAD o el TOC. Se pretende identificar las creencias metacognitivas derivadas del modelo S-REF (Wells y Mathews, 1996, Wells, 2000 que se vincularán en mayor medida al espectro del trastorno de ansiedad generalizada y del trastorno obsesivo-compulsivo y el efecto que dichas creencias pueden tener en el uso de estrategias de control cognitivo. Para ello, una muestra de 75 participantes, 24 con diagnósticod de GAD o de TOC, y 51 sin diagnóstico mentales, fueron evaluados mediante el MCQ-30 y el TCQ. El ANOVA entre los grupos permitió encontrar significativas las mayores puntuaciones en creencias sobre la peligrosidad de no controlar las preocupaciones por parte de los participantes con trastorno de ansiedad. Los análisis de regresión permitieron comprobar que ese tipo de creencias favorecían, además, el uso de estrategias de control cognitivo poco adaptativas, como el castigo.

  20. Cultural adaptation into Spanish of the generalized anxiety disorder-7 (GAD-7 scale as a screening tool

    Pérez-Páramo María

    2010-01-01

    Full Text Available Abstract Background Generalized anxiety disorder (GAD is a prevalent mental health condition which is underestimated worldwide. This study carried out the cultural adaptation into Spanish of the 7-item self-administered GAD-7 scale, which is used to identify probable patients with GAD. Methods The adaptation was performed by an expert panel using a conceptual equivalence process, including forward and backward translations in duplicate. Content validity was assessed by interrater agreement. Criteria validity was explored using ROC curve analysis, and sensitivity, specificity, predictive positive value and negative value for different cut-off values were determined. Concurrent validity was also explored using the HAM-A, HADS, and WHO-DAS-II scales. Results The study sample consisted of 212 subjects (106 patients with GAD with a mean age of 50.38 years (SD = 16.76. Average completion time was 2'30''. No items of the scale were left blank. Floor and ceiling effects were negligible. No patients with GAD had to be assisted to fill in the questionnaire. The scale was shown to be one-dimensional through factor analysis (explained variance = 72%. A cut-off point of 10 showed adequate values of sensitivity (86.8% and specificity (93.4%, with AUC being statistically significant [AUC = 0.957-0.985; p 0.001. Limitations Elderly people, particularly those very old, may need some help to complete the scale. Conclusion After the cultural adaptation process, a Spanish version of the GAD-7 scale was obtained. The validity of its content and the relevance and adequacy of items in the Spanish cultural context were confirmed.

  1. Diurnal changes in polyamine content, arginine and ornithine decarboxylase, and diamine oxidase in tobacco leaves

    Gemperlová, Lenka; Nováková, Marie; Vaňková, Radomíra; Eder, Josef; Cvikrová, Milena

    2006-01-01

    Roč. 57, č. 6 (2006), s. 1413-1421. ISSN 0022-0957 R&D Projects: GA ČR GA206/03/0369 Institutional research plan: CEZ:AV0Z50380511 Keywords : Arginine decarboxylase * diamine oxidase * ornithine decarboxylase Subject RIV: ED - Physiology Impact factor: 3.630, year: 2006

  2. Gestos autolíticos deliberados (GAD) en adolescentes en el Oeste de Londres: Factores socio-culturales

    Dinesh Bhugra; Neil Thompson; Jayshree Singh; Elizabeth Fellow-Smith

    2004-01-01

    Los estudios previos han sugerido que las tasas de gestos autolíticos deliberados (GAD) en adolescentes asiáticos y pertenecientes a otros grupos étnicos minoritarios no son diferentes de aquéllas del grupo mayoritario. En este estudio documentamos los factores socio-culturales implicados en los gestos autolíticos llevados a cabo por los adolescentes del oeste de Londres durante un período de un año. Método. Se contactó con todos los casos de GAD en adolescentes para que participasen en el es...

  3. Mouse ornithine decarboxylase gene: cloning, structure, and expression.

    Brabant, M; McConlogue, L; van Daalen Wetters, T; Coffino, P

    1988-01-01

    We used molecular cloning to isolate a functional gene for mouse ornithine decarboxylase (OrnDCase; L-ornithine carboxy-lyase, EC 4.1.1.17) from a cell line in which that gene had been selectively amplified. The position of the 5' terminus of the mRNA was identified, and the coding sequence was shown to be preceded by a 312- or 313-nucleotide (nt) untranslated leader. The latter is highly G + C rich, particularly in its 5'-most portion. The leader can be anticipated to have extensive and stab...

  4. Antibody-bound amyloid precursor protein upregulates ornithine decarboxylase expression

    Nilsson, Tatjana; Malkiewicz, Katarzyna; Gabrielsson, Maria;

    2006-01-01

    Alzheimer's disease is a neurodegenerative disorder characterised by extracellular accumulation of the Abeta peptide, derived from the amyloid precursor protein (APP). The function of APP as a cell surface receptor was examined by ligand-mimicking using an antibody against the APP extracellular...... signalling events. This study shows that antibody-bound APP leads to altered gene expression that may be relevant to AD....... domain. Alterations in gene expression evoked by antibody-bound APP were analysed using human pathway-finder gene arrays and the largest change in expression levels was found for ornithine decarboxylase (ODC). These results were confirmed by Western blotting which showed even higher upregulation on the...

  5. Structural Characterization of the Molecular Events during a Slow Substrate-Product Transition in Orotidine 5'-Monophosphate Decarboxylase

    Fujihashi, Masahiro; Wei, Lianhu; Kotra, Lakshmi P; Pai, Emil F; (TGRI); (Toronto); (Kyoto)

    2009-04-06

    Crystal structures of substrate-product complexes of Methanobacterium thermoautotrophicum orotidine 5'-monophosphate decarboxylase, obtained at various steps in its catalysis of the unusual transformation of 6-cyano-uridine 5'-monophosphate (UMP) into barbituric acid ribosyl monophosphate, show that the cyano substituent of the substrate, when bound to the active site, is first bent significantly from the plane of the pyrimidine ring and then replaced by an oxygen atom. Although the K72A and D70A/K72A mutants are either catalytically impaired or even completely inactive, they still display bending of the C6 substituent. Interestingly, high-resolution structures of the D70A and D75N mutants revealed a covalent bond between C6 of UMP and the Lys72 side chain after the -CN moiety's release. The same covalent bond was observed when the native enzyme was incubated with 6-azido-UMP and 6-iodo-UMP; in contrast, the K72A mutant transformed 6-iodo-UMP to barbituric acid ribosyl 5'-monophosphate. These results demonstrate that, given a suitable environment, native orotidine 5'-monophosphate decarboxylase and several of its mutants are not restricted to the physiologically relevant decarboxylation; they are able to catalyze even nucleophilic substitution reactions but consistently maintain distortion on the C6 substituent as an important feature of catalysis.

  6. Molecular and biochemical characterisation of ornithine decarboxylases in the sheep abomasal nematode parasites Teladorsagia circumcincta and Haemonchus contortus.

    Umair, Saleh; Knight, Jacqueline S; Simpson, Heather V

    2013-06-01

    Full length cDNA encoding ornithine decarboxylases (ODC; EC 4.1.1.17) were cloned from the sheep abomasal nematode parasites Teladorsagia circumcincta (TcODC) and Haemonchus contortus (HcODC). The TcODC (1272 bp) and HcODC cDNA (1266 bp) encoded 424 and 422 amino acid proteins respectively. The predicted TcODC amino acid sequence showed 87% identity with HcODC and 65% and 64% with Caenorhabditis elegans and Caenorhabditis briggsae ODC respectively. All binding sites and active regions were completely conserved in both proteins. Soluble N-terminal His-tagged ODC proteins were expressed in Escherichia coli strain BL21, purified and characterised. The recombinant TcODC and HcODC had very similar kinetic properties: K(m) ornithine was 0.2-0.25 mM, optimum [PLP] was 0.3 mM and the pH optima were pH 8. No enzyme activity was detected when arginine was used as substrate. One millimolar difluoromethylornithine (DFMO) completely inhibited TcODC and HcODC activity, whereas 2 mM agmatine did not inhibit activity. The present study showed that ODC is a separate enzyme from arginine decarboxylase and strictly uses ornithine as substrate. PMID:23499950

  7. Lack of Support for the Association Between GAD2 Polymorphisms andSevere Human Obesity

    Swarbrick, Michael M.; Waldenmaier, Bjorn; Pennacchio, Len A.; Lind,Denise L.; Cavazos, Martha M.; Geller, Frank; Merriman, Raphael; Ustaszewska, Anna; Malloy, Mary; Scherag, Andre; Hsueh, Wen-Chi; Rief,Winfried; Mauvais-Jarvis, Franck; Pullinger, Clive R.; Kane, John P.; Dent, Robert; McPherson, Ruth; Kwok, Pui-Yan; Hinney, Anke; Hebebrand,Johannes; Vaisse, Christian

    2004-11-17

    Demonstration of association between common genetic variants and chronic human diseases such as obesity could have profound implications for the prediction, prevention and treatment of these conditions. Unequivocal proof of such an association, however, requires adherence to established methodological guidelines, which include independent replication of initial positive findings. Recently, single nucleotide polymorphisms (SNPs) within GAD2 were found to be associated with class III obesity (BMI > 40 kg/m2) in 188 families (612 individuals) segregating the condition and a case-control study of 575 cases and 646 lean controls. Functional data supporting a pathophysiological role for one of the SNPs (-243A>G) were also presented. In the present study, we attempted to replicate this association in larger groups of subjects, and to extend the functional studies of the -243A>G SNP. In 2,327 subjects comprising 692 German nuclear families with severe, early-onset obesity, we found no evidence for a relationship between the three GAD2 SNPs and obesity, whether SNPs were studied individually or as haplotypes. In two independent case-control studies (a total of 680 class III obesity cases and 1,186 lean controls), there was no significant relationship between the -243A>G SNP and obesity (odds ratio (OR) = 0.99, 95% CI 0.83 - 1.18,in the pooled sample). These negative findings were reinforced by a meta-analysis for the association between the 243G allele and class III obesity, which yielded an OR of 1.11 (95% CI 0.90 - 1.36) in a total sample of 1,252 class III obese cases and 1,800 lean controls. Finally,we were unable to confirm or extend the functional data pertaining to the -243A>G variant. Potential confounding variables in association studies involving common variants and complex diseases (low power to detect modest genetic effects, over-interpretation of marginal data, population stratification and biological plausibility) are also discussed in the context of GAD2 and

  8. Crystal structure of pyruvate decarboxylase from Zymobacter palmae.

    Buddrus, Lisa; Andrews, Emma S V; Leak, David J; Danson, Michael J; Arcus, Vickery L; Crennell, Susan J

    2016-09-01

    Pyruvate decarboxylase (PDC; EC 4.1.1.1) is a thiamine pyrophosphate- and Mg(2+) ion-dependent enzyme that catalyses the non-oxidative decarboxylation of pyruvate to acetaldehyde and carbon dioxide. It is rare in bacteria, but is a key enzyme in homofermentative metabolism, where ethanol is the major product. Here, the previously unreported crystal structure of the bacterial pyruvate decarboxylase from Zymobacter palmae is presented. The crystals were shown to diffract to 2.15 Å resolution. They belonged to space group P21, with unit-cell parameters a = 204.56, b = 177.39, c = 244.55 Å and Rr.i.m. = 0.175 (0.714 in the highest resolution bin). The structure was solved by molecular replacement using PDB entry 2vbi as a model and the final R values were Rwork = 0.186 (0.271 in the highest resolution bin) and Rfree = 0.220 (0.300 in the highest resolution bin). Each of the six tetramers is a dimer of dimers, with each monomer sharing its thiamine pyrophosphate across the dimer interface, and some contain ethylene glycol mimicking the substrate pyruvate in the active site. Comparison with other bacterial PDCs shows a correlation of higher thermostability with greater tetramer interface area and number of interactions. PMID:27599861

  9. Adenovirus-mediated Expression of both Antisense Ornithine Decarboxylase and S-adenosylmethionine Decarboxylase Inhibits Lung Cancer Cell Growth

    Hui TIAN; Xianxi LIU; Bing ZHANG; Qifeng SUN; Dongfeng SUN

    2007-01-01

    Polyamine biosynthesis is controlled primarily by ornithine decarboxylase (ODC) and Sadenosylmethionine decarboxylase (AdoMetDC). Antisense sequences of ODC and AdoMetDC genes were cloned into an adenoviral vector (named Ad-ODC-AdoMetDCas). To evaluate the effects of recombinant adenovirus Ad-ODC-AdoMetDCas that can simultaneously express both antisense ODC and AdoMetDC,the human lung cancer cell line A-549 was infected with Ad-ODC-AdoMetDCas or the control vector.Viable cell counting, determination of polyamine concentrations, cell cycle analysis, and Matrigel invasion assays were carried out to assess the properties of tumor growth and invasiveness. Our study showed that adenovirus-mediated antisense ODC and AdoMetDC expression inhibits tumor cell growth through blocking the polyamine synthesis pathway. Tumor cells were arrested at the G1 phase after gene transfer and the invasiveness was reduced. It suggested that the recombinant adenovirus Ad-ODC-AdoMetDCas might be a new anticancer reagent in the treatment of lung cancers.

  10. Auxins Induce Tryptophan Decarboxylase Activity in Radicles of Catharanthus Seedlings 1

    Aerts, Rob J.; Alarco, Anne-Marie; De Luca, Vincenzo

    1992-01-01

    Germinating seedlings of Catharanthus roseus produce monoterpenoid indole alkaloids as a result of a transient increase of tryptophan decarboxylase (TDC) activity. The influence of auxins on this transient rise of TDC activity was studied. External application of indolebutyric acid or 2,4-dichlorophenoxyacetic acid at a concentration of 20 to 40 μm enhanced and prolonged the rise in TDC activity in developing seedlings. Auxin treatment also influenced the morphology of the seedlings; it induced a shortening and thickening of the hypocotyl and the radicle and promoted the initiation of lateral roots in the radicle. During development, the radicles of auxin-treated seedlings displayed a gradual increase in TDC activity that was absent in the radicles of untreated controls. Examination of immunoblots revealed anti-TDC reactive proteins in extracts from radicles of auxin-treated seedlings, but none in extracts from radicles of control seedlings. In contrast, TDC activity and immunoreactive protein levels in the aerial parts of controls and auxin-treated seedlings were comparable. Our results indicate that externally applied auxins induce both abnormal development and TDC activity in the radicles of Catharanthus seedlings. Although auxins slightly delayed the light-mediated induction of the cotyledon-specific last step in vindoline biosynthesis (i.e. acetylcoenzyme A: deacetylvindolin-O-acetyltransferase activity), seedlings still synthesized vindoline, one of the major alkaloid end products. Images Figure 2 PMID:16653009

  11. An endosymbiont positively modulates ornithine decarboxylase in host trypanosomatids

    Summary: Some trypanosomatids, such as Crithidia deanei, are endosymbiont-containing species. Aposymbiotic strains are obtained after antibiotic treatment, revealing interesting aspects of this symbiotic association. Ornithine decarboxylase (ODC) promotes polyamine biosynthesis and contributes to cell proliferation. Here, we show that ODC activity is higher in endosymbiont-bearing trypanosomatids than in aposymbiotic cells, but isolated endosymbionts did not display this enzyme activity. Intriguingly, expressed levels of ODC were similar in both strains, suggesting that ODC is positively modulated in endosymbiont-bearing cells. When the aposymbiotic strain was grown in conditioned medium, obtained after cultivation of the endosymbiont-bearing strain, cellular proliferation as well as ODC activity and localization were similar to that observed in the endosymbiont-containing trypanosomatids. Furthermore, dialyzed-heated medium and trypsin treatment reduced ODC activity of the aposymbiont strain. Taken together, these data indicate that the endosymbiont can enhance the protozoan ODC activity by providing factors of protein nature, which increase the host polyamine metabolism

  12. A role for Lon protease in the control of the acid resistance genes of Escherichia coli.

    Heuveling, Johanna; Possling, Alexandra; Hengge, Regine

    2008-07-01

    Lon protease is a major protease in cellular protein quality control, but also plays an important regulatory role by degrading various naturally unstable regulators. Here, we traced additional such regulators by identifying regulons with co-ordinately altered expression in a lon mutant by genome-wide transcriptional profiling. Besides many members of the RcsA regulon (which validates our approach as RcsA is a known Lon substrate), many genes of the sigmaS-dependent general stress response were upregulated in the lon mutant. However, the lon mutation did not affect sigmaS levels nor sigmaS activity in general, suggesting specific effects of Lon on secondary regulators involved in the control of subsets of sigmaS-controlled genes. Lon-affected genes also included the major acid resistance genes (gadA, gadBC, gadE, hdeAB and hdeD), which led to the discovery that the essential acid resistance regulator GadE (whose expression is sigmaS-controlled) is degraded in vivo in a Lon-dependent manner. GadE proteolysis is constitutive as it was observed even under conditions that induce the system (i.e. at low pH or during entry into stationary phase). GadE degradation was found to rapidly terminate the acid resistance response upon shift back to neutral pH and to avoid overexpression of acid resistance genes in stationary phase. PMID:18630346

  13. Characterization and Heterologous Expression of the Oxalyl Coenzyme A Decarboxylase Gene from Bifidobacterium lactis

    Federici, Federica; Vitali, Beatrice; Gotti, Roberto; Pasca, Maria Rosalia; Gobbi, Silvia; Peck, Ammon B; Brigidi, Patrizia

    2004-01-01

    Oxalyl coenzyme A (CoA) decarboxylase (Oxc) is a key enzyme in the catabolism of the highly toxic compound oxalate, catalyzing the decarboxylation of oxalyl-CoA to formyl-CoA. The gene encoding a novel oxalyl-CoA decarboxylase from Bifidobacterium lactis DSM 10140 (oxc) was identified and characterized. This strain, isolated from yogurt, showed the highest oxalate-degrading activity in a preliminary screening with 12 strains belonging to Bifidobacterium, an anaerobic intestinal bacterial grou...

  14. Enzymatic and immunological studies of uroporphyrinogen decarboxylase in familial porphyria cutanea tarda and hepatoerythropoietic porphyria.

    De Verneuil, H.; Beaumont, C; Deybach, J C; Nordmann, Y; Sfar, Z; Kastally, R

    1984-01-01

    Uroporphyrinogen decarboxylase activity was measured in hemoglobin-free lysates from two patients with hepatoerythropoietic porphyria (HEP) and from 12 unrelated patients with familial porphyria cutanea tarda (PCT). In HEP patients, enzyme activities were 5% of normal, and familial studies clearly confirmed that patients with HEP are cases of homozygous PCT. Immunoreactive uroporphyrinogen decarboxylase was measured by developing a direct and noncompetitive enzyme immunoassay (EIA). For the 1...

  15. Structure and Function of 4-Hydroxyphenylacetate Decarboxylase and Its Cognate Activating Enzyme.

    Selvaraj, Brinda; Buckel, Wolfgang; Golding, Bernard T; Ullmann, G Matthias; Martins, Berta M

    2016-01-01

    4-Hydroxyphenylacetate decarboxylase (4Hpad) is the prototype of a new class of Fe-S cluster-dependent glycyl radical enzymes (Fe-S GREs) acting on aromatic compounds. The two-enzyme component system comprises a decarboxylase responsible for substrate conversion and a dedicated activating enzyme (4Hpad-AE). The decarboxylase uses a glycyl/thiyl radical dyad to convert 4-hydroxyphenylacetate into p-cresol (4-methylphenol) by a biologically unprecedented Kolbe-type decarboxylation. In addition to the radical dyad prosthetic group, the decarboxylase unit contains two [4Fe-4S] clusters coordinated by an extra small subunit of unknown function. 4Hpad-AE reductively cleaves S-adenosylmethionine (SAM or AdoMet) at a site-differentiated [4Fe-4S]2+/+ cluster (RS cluster) generating a transient 5'-deoxyadenosyl radical that produces a stable glycyl radical in the decarboxylase by the abstraction of a hydrogen atom. 4Hpad-AE binds up to two auxiliary [4Fe-4S] clusters coordinated by a ferredoxin-like insert that is C-terminal to the RS cluster-binding motif. The ferredoxin-like domain with its two auxiliary clusters is not vital for SAM-dependent glycyl radical formation in the decarboxylase, but facilitates a longer lifetime for the radical. This review describes the 4Hpad and cognate AE families and focuses on the recent advances and open questions concerning the structure, function and mechanism of this novel Fe-S-dependent class of GREs. PMID:26959876

  16. Aspartate beta-decarboxylase from Alcaligenes faecalis: carbon-13 kinetic isotope effect and deuterium exchange experiments

    The authors have measured the 13C kinetic isotope effect at pH 4.0, 5.0, 6.0, and 6.5 and in D2O at pH 5.0 and the rate of D-H exchange of the alpha and beta protons of aspartic acid in D2O at pH 5.0 for the reaction catalyzed by the enzyme aspartate beta-decarboxylase from Alcaligenes faecalis. The 13C kinetic isotope effect, with a value of 1.0099 +/- 0.0002 at pH 5.0, is less than the intrinsic isotope effect for the decarboxylation step, indicating that the decarboxylation step is not entirely rate limiting. The authors have been able to estimate probable values of the relative free energies of the transition states of the enzymatic reaction up to and including the decarboxylation step from the 13C kinetic isotope effect and the rate of D-H exchange of alpha-H. The pH dependence of the kinetic isotope effect reflects the pKa of the pyridine nitrogen of the coenzyme pyridoxal 5'-phosphate but not that of the imine nitrogen. A mechanism is proposed for the exchange of aspartate beta-H that is consistent with the stereochemistry suggested earlier

  17. Overexpression of Actinidia deliciosa pyruvate decarboxylase 1 gene enhances waterlogging stress in transgenic Arabidopsis thaliana.

    Zhang, Ji-Yu; Huang, Sheng-Nan; Wang, Gang; Xuan, Ji-Ping; Guo, Zhong-Ren

    2016-09-01

    Ethanolic fermentation is classically associated with waterlogging tolerance when plant cells switch from respiration to anaerobic fermentation. Pyruvate decarboxylase (PDC), which catalyzes the first step in this pathway, is thought to be the main regulatory enzyme. Here, we cloned a full-length PDC cDNA sequence from kiwifruit, named AdPDC1. We determined the expression of the AdPDC1 gene in kiwifruit under different environmental stresses using qRT-PCR, and the results showed that the increase of AdPDC1 expression during waterlogging stress was much higher than that during salt, cold, heat and drought stresses. Overexpression of kiwifruit AdPDC1 in transgenic Arabidopsis enhanced the resistance to waterlogging stress but could not enhance resistance to cold stress at five weeks old seedlings. Overexpression of kiwifruit AdPDC1 in transgenic Arabidopsis could not enhance resistance to NaCl and mannitol stresses at the stage of seed germination and in early seedlings. These results suggested that the kiwifruit AdPDC1 gene is required during waterlogging but might not be required during other environmental stresses. Expression of the AdPDC1 gene was down-regulated by abscisic acid (ABA) in kiwifruit, and overexpression of the AdPDC1 gene in Arabidopsis inhibited seed germination and root length under ABA treatment, indicating that ABA might negatively regulate the AdPDC1 gene under waterlogging stress. PMID:27191596

  18. Aspartate beta-decarboxylase from Alcaligenes faecalis: carbon-13 kinetic isotope effect and deuterium exchange experiments

    Rosenberg, R.M.; O' Leary, M.H.

    1985-03-26

    The authors have measured the /sup 13/C kinetic isotope effect at pH 4.0, 5.0, 6.0, and 6.5 and in D/sub 2/O at pH 5.0 and the rate of D-H exchange of the alpha and beta protons of aspartic acid in D/sub 2/O at pH 5.0 for the reaction catalyzed by the enzyme aspartate beta-decarboxylase from Alcaligenes faecalis. The /sup 13/C kinetic isotope effect, with a value of 1.0099 +/- 0.0002 at pH 5.0, is less than the intrinsic isotope effect for the decarboxylation step, indicating that the decarboxylation step is not entirely rate limiting. The authors have been able to estimate probable values of the relative free energies of the transition states of the enzymatic reaction up to and including the decarboxylation step from the /sup 13/C kinetic isotope effect and the rate of D-H exchange of alpha-H. The pH dependence of the kinetic isotope effect reflects the pKa of the pyridine nitrogen of the coenzyme pyridoxal 5'-phosphate but not that of the imine nitrogen. A mechanism is proposed for the exchange of aspartate beta-H that is consistent with the stereochemistry suggested earlier.

  19. Nucleotide variation at the dopa decarboxylase (Ddc) gene in natural populations of Drosophila melanogaster

    Andrey Tatarenkov; Francisco J. Ayala

    2007-08-01

    We studied nucleotide sequence variation at the gene coding for dopa decarboxylase (Ddc) in seven populations of Drosophila melanogaster. Strength and pattern of linkage disequilibrium are somewhat distinct in the extensively sampled Spanish and Raleigh populations. In the Spanish population, a few sites are in strong positive association, whereas a large number of sites in the Raleigh population are associated nonrandomly but the association is not strong. Linkage disequilibrium analysis shows presence of two groups of haplotypes in the populations, each of which is fairly diverged, suggesting epistasis or inversion polymorphism. There is evidence of two forms of natural selection acting on Ddc. The McDonald–Kreitman test indicates a deficit of fixed amino acid differences between D. melanogaster and D. simulans, which may be due to negative selection. An excess of derived alleles at high frequency, significant according to the -test, is consistent with the effect of hitchhiking. The hitchhiking may have been caused by directional selection downstream of the locus studied, as suggested by a gradual decrease of the polymorphism-to-divergence ratio. Altogether, the Ddc locus exhibits a complicated pattern of variation apparently due to several evolutionary forces. Such a complex pattern may be a result of an unusually high density of functionally important genes.

  20. The Impact of Pretrauma Analogue GAD and Posttraumatic Emotional Reactivity Following Exposure to the September 11 Terrorist Attacks: A Longitudinal Study

    Farach, Frank J.; Mennin, Douglas S.; Smith, Rita L.; Mandelbaum, Matthew

    2008-01-01

    The relation between analogue generalized anxiety disorder (GAD) assessed the day before the events of September 11, 2001 (9/11), and long-term outcome was examined in 44 young adults who were directly exposed the following day to the terrorist attacks in New York City. After controlling for high exposure to the attacks, preattack analogue GAD was associated with greater social and work disability, loss of psychosocial resources, anxiety and mood symptoms, and worry, but not symptoms of po...

  1. On-line near-infrared spectroscopy optimizing and monitoring biotransformation process ofγ-aminobutyric acid$

    Guoyu Ding; Yuanyuan Hou; Jiamin Peng; Yunbing Shen; Min Jiang; Gang Bai

    2016-01-01

    Near-infrared spectroscopy (NIRS) with its fast and nondestructive advantages can be qualified for the real-time quantitative analysis. This paper demonstrates that NIRS combined with partial least squares (PLS) regression can be used as a rapid analytical method to simultaneously quantify L-glutamic acid (L-Glu) andγ-aminobutyric acid (GABA) in a biotransformation process and to guide the optimization of production conditions when the merits of NIRS are combined with response surface methodology. The high performance liquid chromatography (HPLC) reference analysis was performed by the o-phthaldialdehyde pre-column derivatization. NIRS measurements of two batches of 141 samples were firstly analyzed by PLS with several spectral pre-processing methods. Compared with those of the HPLC reference analysis, the resulting determination coefficients (R2), root mean square error of prediction (RMSEP) and residual predictive deviation (RPD) of the external validation for the L-Glu concentration were 99.5%, 1.62 g/L, and 11.3, respectively. For the GABA concentration, R2, RMSEP, and RPD were 99.8%, 4.00 g/L, and 16.4, re-spectively. This NIRS model was then used to optimize the biotransformation process through a Box-Behnken experimental design. Under the optimal conditions without pH adjustment, 200 g/L L-Glu could be catalyzed by 7148 U/L glutamate decarboxylase (GAD) to GABA, reaching 99%conversion at the fifth hour. NIRS analysis provided timely information on the conversion from L-Glu to GABA. The results suggest that the NIRS model can not only be used for the routine profiling of enzymatic conversion, providing a simple and effective method of monitoring the biotransformation process of GABA, but also be considered to be an optimal tool to guide the optimization of production conditions.

  2. On-line near-infrared spectroscopy optimizing and monitoring biotransformation process of γ-aminobutyric acid

    Guoyu Ding

    2016-06-01

    Full Text Available Near-infrared spectroscopy (NIRS with its fast and nondestructive advantages can be qualified for the real-time quantitative analysis. This paper demonstrates that NIRS combined with partial least squares (PLS regression can be used as a rapid analytical method to simultaneously quantify l-glutamic acid (l-Glu and γ-aminobutyric acid (GABA in a biotransformation process and to guide the optimization of production conditions when the merits of NIRS are combined with response surface methodology. The high performance liquid chromatography (HPLC reference analysis was performed by the o-phthaldialdehyde pre-column derivatization. NIRS measurements of two batches of 141 samples were firstly analyzed by PLS with several spectral pre-processing methods. Compared with those of the HPLC reference analysis, the resulting determination coefficients (R2, root mean square error of prediction (RMSEP and residual predictive deviation (RPD of the external validation for the l-Glu concentration were 99.5%, 1.62 g/L, and 11.3, respectively. For the GABA concentration, R2, RMSEP, and RPD were 99.8%, 4.00 g/L, and 16.4, respectively. This NIRS model was then used to optimize the biotransformation process through a Box-Behnken experimental design. Under the optimal conditions without pH adjustment, 200 g/L l-Glu could be catalyzed by 7148 U/L glutamate decarboxylase (GAD to GABA, reaching 99% conversion at the fifth hour. NIRS analysis provided timely information on the conversion from l-Glu to GABA. The results suggest that the NIRS model can not only be used for the routine profiling of enzymatic conversion, providing a simple and effective method of monitoring the biotransformation process of GABA, but also be considered to be an optimal tool to guide the optimization of production conditions.

  3. Superior perception of phasic physiological arousal and the detrimental consequences of the conviction to be aroused on worrying and metacognitions in GAD.

    Andor, Tanja; Gerlach, Alexander L; Rist, Fred

    2008-02-01

    Although people suffering from generalized anxiety disorder (GAD) often report arousal symptoms, psychophysiological studies show no evidence of autonomic hyperarousal. Hypersensitivity toward and catastrophic interpretation of phasic arousal cues may explain this discrepancy. The authors tested (a) whether GAD sufferers perceive nonspecific skin conductance fluctuations (NSCFs), an indicator of phasic autonomic arousal, better than controls do and (b) whether the conviction to be aroused contributes to the maintenance of worrying and metacognitive beliefs about worrying. Thirty-three GAD sufferers and 34 healthy controls participated in 2 experiments. In Experiment 1, participants were asked to detect their own NSCFs during a signal detection task. GAD sufferers accurately detected more of their NSCFs than did controls, who tended to miss NSCFs. In Experiment 2, participants were instructed to relax following worry induction. While relaxing, they received nonveridical feedback indicating either arousal or relaxation. Arousal feedback conserved negative metacognitive beliefs regarding worrying and also maintained negative mood and worry exclusively in GAD participants. These findings suggest that superior perception of phasic arousal cues and their catastrophic misinterpretation increases worrying, negative metacognitive beliefs about worrying, and anxious mood in GAD. PMID:18266497

  4. Ornithine decarboxylase gene is overexpressed in colorectal carcinoma

    Hai-Yan Hu; Bing Zhang; Xian-Xi Liu; Chun-Ying Jiang; Yi Lu; Shi-Lian Liu; Ji-Feng Bian; Xiao-Ming Wang; Zhao Geng; Yan Zhang

    2005-01-01

    AIM: To investigate the ornithine decarboxylase (ODC)gene expression in colorectal carcinoma, ODC mRNA was assayed by RT-PCR and ODC protein was detected by a monoclonal antibody against fusion of human colon ODC prepared by hybridoma technology.METHODS: Total RNA was extracted from human colorectal cancer tissues and their normal counterpart tissues. ODC mRNA levels were examined by RT-PCR.ODC genes amplified from RT-PCR were cloned into a prokaryotic vector pQE-30. The expressed proteins were purified by chromatography. Anti-ODC mAb was prepared with classical hybridoma techniques and used to determine the ODC expression in colon cancer tissues by immunohistochemical and Western blotting assay.RESULTS: A cell line, which could steadily secrete antiODC mAb, was selected through subcloning four times.Western blotting reconfirmed the mAb and ELISA showed that its subtype was IgG2a. RT-PCR showed that the ODC mRNA level increased greatly in colon cancer tissues (P<0.01). Immunohistochemical staining showed that colorectal carcinoma cells expressed a significantly higher level of ODC than normal colorectal mucosa (98.6±1.03%vs 5.26±5%, P<0.01).CONCLUSION: ODC gene overexpression is significantly related to human colorectal carcinoma. ODC gene expression may be a marker for the gene diagnosis and therapy of colorectal carcinoma.

  5. Localization of histidine decarboxylase mRNA in rat brain.

    Bayliss, D A; Wang, Y M; Zahnow, C A; Joseph, D R; Millhorn, D E

    1990-08-01

    The recent cloning of a cDNA encoding fetal rat liver histidine decarboxylase (HDC), the synthesizing enzyme for histamine, allows the study of the central histaminergic system at the molecular level. To this end, Northern blot and in situ hybridization analyses were used to determine the regional and cellular distribution of neurons which express HDC mRNA in rat brain. Three hybridizing species which migrate as 1.6-, 2.6-, and 3.5-kb RNA were identified with Northern blots. The major (2.6 kb) and minor (3.5 kb) species, characteristic of HDC mRNA in fetal liver, were expressed at high levels in diencephalon and at just detectable levels in hippocampus, but not in other brain regions. In contrast, the 1.6-kb species was present in all brain regions examined except the olfactory bulb. Cells which contain HDC mRNA were found by in situ hybridization in the hypothalamus; HDC mRNA-containing cells were not detected in other areas, including the hippocampus. Hypothalamic neurons which express HDC mRNA were localized to all aspects of the tuberomammillary nucleus, a result consistent with previous immunohistochemical findings. PMID:19912749

  6. Ornithine decarboxylase antizyme inhibitor 2 regulates intracellular vesicle trafficking

    Kanerva, Kristiina; Maekitie, Laura T. [Department of Pathology, Haartman Institute, University of Helsinki, Helsinki (Finland); Baeck, Nils [Department of Anatomy, Institute of Biomedicine, University of Helsinki, Helsinki (Finland); Andersson, Leif C., E-mail: leif.andersson@helsinki.fi [Department of Pathology, Haartman Institute, University of Helsinki, Helsinki (Finland); HUSLAB, Helsinki (Finland); Department of Oncology and Pathology, Karolinska Institutet, Stockholm (Sweden)

    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.

  7. Amiloride inhibits rat mucosal ornithine decarboxylase activity and DNA synthesis

    Refeeding fasted rats induces a dramatic trophic response in gastrointestinal mucosa and is associated with elevations in both rate of DNA synthesis and ornithine decarboxylase (ODC) activity. The signal for these increases is unknown. Amiloride prevents cell alkalinization by blocking Na+-H+ exchange at apical epithelial cell membranes. In study 1, rats were fasted 48 h, treated with amiloride (0.5 to 500 mg/kg), and refed for 4 h. Refeeding increased ODC activities in the jejunal mucosa (X8) and liver (X19) but not in the oxyntic gland mucosa. In the jejunum, but not the liver, the activation of ODC was completely abolished by 100 mg/kg amiloride. In study 2, the rate of DNA synthesis was determine by measuring the rate of [3H]thymidine incorporation 16 h after refeeding. Refeeding resulted in significantly increased rates of DNA synthesis over fasted levels, and amiloride at 100 mg/kg significantly reduced the elevations in the jejenum and liver. In conclusion, amiloride inhibits the postprandial increases in jejunal ODC activity and DNA synthesis in the jejunum and liver. The results indicate that (1) the Na+-H+ antiport is essential to the increased ODC activity in the jejunum and liver after a meal and (2) increases in DNA synthesis and their suppression by amiloride are not necessary linked to ODC activity

  8. Lack of evidence for the association of ornithine decarboxylase (+316 G>A), spermidine/spermine acetyl transferase (−1415 T>C) gene polymorphisms with calcium oxalate stone disease

    ÇOKER-GÜRKAN, AJDA; Arisan, Serdar; ARISAN, ELIF DAMLA; ÜNSAL, NARÇIN PALAVAN

    2013-01-01

    Urolithiasis is a complex and multifactorial disorder characterized by the presence of stones in the urinary tract. Urea cycle is an important process involved in disease progression. L-ornithine is a key amino acid in the urea cycle and is converted to putrescine by ornithine decarboxylase (ODC). Putrescine, spermidine and spermine are natural polyamines that are catabolized by a specific enzyme, spermidine/spermine acetyltransferase (SSAT). The single-nucleotide polymorphisms (SNPs) in the ...

  9. Ornithine decarboxylase as an early indicator of in vitro hepatocyte DNA synthesis

    The enzyme ornithine decarboxylase, one of the key enzymes involved in polyamine biosynthesis, catalyzes the decarboxylation of ornithine to give putrescine. The activity of this enzyme in an in vitro hepatocyte culture assay system was measured because it is known that ornithine decarboxylase levels increase in instances where active protein synthesis, DNA synthesis, and cell growth is initiated. A good correlation was found between ornithine decarboxylase activity and the rate of tritiated thymidine incorporation into hepatocyte DNA. The increase in enzyme activity precedes the incorporation of tritiated thymidine into DNA (enzyme activity increases 2-3 hr following stimulation of cell growth; whereas the tritiated thymidine uptake increases at about 14-18 hr). Experimental results obtained with this assay system, suggest that hepatocytes from the regenerating liver remnant, grown in vitro, secrete a factor(s) into the culture medium which stimulates DNA synthesis of normal hepatocytes. Use of the increase in ornithine decarboxylase activity in this hepatocyte monolayer culture system confirmed the observation made by several investigators: that the serum of rats which underwent partial hepatectomy contains a factor(s) which stimulates hepatocyte DNA synthesis in vitro. In conclusion, these results suggest that ornithine decarboxylase activity can be used as a sensitive, early indicator of the degree of stimulation of hepatocyte DNA synthesis and thus be of use in determining the effect of various trophic factors on hepatocyte DNA synthesis in vitro

  10. Stiff-Person Syndrome: Case Series

    Yu Jin Jung

    2014-04-01

    Full Text Available Stiff-person syndrome (SPS is a rare disorder, characterized by progressive fluctuating muscular rigidity and spasms. Glutamic acid decarboxylase (GAD antibody is primarily involved in the pathogenesis of SPS and SPS is strongly associated with other autoimmune disease. Here we report three cases of patients with classical SPS finally confirmed by high serum level of GAD antibodies. All of our patients respond favorably to gamma amino butyric acid-enhancing drugs and immunotherapies.

  11. Analysis of a 30 kbp plasmid encoding histidine decarboxylase gene in Tetragenococcus halophilus isolated from fish sauce.

    Satomi, Masataka; Furushita, Manabu; Oikawa, Hiroshi; Yoshikawa-Takahashi, Miwako; Yano, Yutaka

    2008-08-15

    In order to analyze the genes related to the histamine production, a strain of histamine producing halophilic bacteria, referred to as strain H, was isolated using enrichment culture and dilution-to-extinction methods with histidine broth inoculated from the fish sauce mashes. The two Japanese fish sauce mashes used, accumulate over 1000 mg/l of histamine. Phenotypic and 16 S rRNA gene sequence analyses identified strain H as Tetragenococcus halophilus, the predominant histamine producing bacteria present during fish sauce fermentation. Genetic analyses (PCR and Southern blot) of the histamine producing strain confirmed that the strain harbored a 30 kbp plasmid (pHDC) encoding a single copy of the pyruvoyl dependent histidine decarboxylase gene (hdc). A comparison of hdcA that is a structural gene of histidine decarboxylase among strain H, Lactobacillus hilgardii 0006, L. sakei LTH2076, Oenococcus oeni 9204, T. halophilus and T. muriaticus JCM10006 (T) indicated >99% sequence similarity. The hdc gene cluster consisted of 4 ORFs, hdcP, hdcA, hdcB, and hdcRS, and were almost identical to that of L. hilgardii 0006 with 99% sequence similarity including the structural hdc spacer region. However, the approximately 500 bp regions upstream and downstream of the hdc gene were different between that of strain H and L. hilgardii 0006. The complete sequence of pHDC revealed 29,924 nucleotides including 28 ORFs, two pairs of IR (inverted repeat), similar sequence of plasmid conjugative elements, and a theta-type replicon. These results suggested that hdc could be encoded on transformable elements among lactic acid bacteria. PMID:18573560

  12. Endogenous synthesis of taurine and GABA in rat ocular tissues

    The endogenous production of taurine and γ-aminobutyric acid (GABA) in rat ocular tissues was investigated. The activities of taurine-producing enzyme, cysteine sulfinic acid decarboxylase (CSAD), and GABA-synthesizing enzyme, glutamic acid decarboxylase (GAD), were observed in the retina, lens, iris-ciliary body and cornea. The highest specific activity of CSAD was in the cornea and that of GAD in the retina. The discrepancy between CSAD activity and taurine content within the ocular tissues indicates that intra- or extraocular transport processes may regulate the concentration of taurine on the rat eye. The GAD activity and the content of GABA were distributed in parallel within the rat ocular tissues. The quantitative results suggest that the GAD/GABA system has functional significance only in the retina of the rat eye. (author)

  13. Chilling Tolerance of Cucumber During Germination is Related to Expression of Lysine Decarboxylase Gene

    LU Ming-hui; LI Xiao-ming; CHEN Jin-feng; CHEN Long-zheng; QIAN Chun-tao

    2005-01-01

    Using cDNA-AFLP technique, a specific fragment was isolated from cucumber cultivar Changchun mici possessing chilling tolerance induced at low temperature (15℃). This fragment, named cctr 132, could not be induced in the chilling sensitive cucumber cultivar Beijing jietou. After recovering the fragment, sequencing and translating, the results of blastx and blastp in GenBank of NCBI indicated that CCTR132 had 88.37% identities and 100% positives with Oryza sativa putative lysine decarboxylase-like protein respectively, and PGGXGTXXE, the putative conserved domain of lysine decarboxylase family, was detected from CCTR132, suggesting the cucumber chilling tolerance during germination is related to the expression of the lysine decarboxylase gene.

  14. Structural Basis for Nucleotide Binding and Reaction Catalysis in Mevalonate Diphosphate Decarboxylase

    Barta, Michael L.; McWhorter, William J.; Miziorko, Henry M.; Geisbrecht, Brian V. (UMKC)

    2012-09-17

    Mevalonate diphosphate decarboxylase (MDD) catalyzes the final step of the mevalonate pathway, the Mg{sup 2+}-ATP dependent decarboxylation of mevalonate 5-diphosphate (MVAPP), producing isopentenyl diphosphate (IPP). Synthesis of IPP, an isoprenoid precursor molecule that is a critical intermediate in peptidoglycan and polyisoprenoid biosynthesis, is essential in Gram-positive bacteria (e.g., Staphylococcus, Streptococcus, and Enterococcus spp.), and thus the enzymes of the mevalonate pathway are ideal antimicrobial targets. MDD belongs to the GHMP superfamily of metabolite kinases that have been extensively studied for the past 50 years, yet the crystallization of GHMP kinase ternary complexes has proven to be difficult. To further our understanding of the catalytic mechanism of GHMP kinases with the purpose of developing broad spectrum antimicrobial agents that target the substrate and nucleotide binding sites, we report the crystal structures of wild-type and mutant (S192A and D283A) ternary complexes of Staphylococcus epidermidis MDD. Comparison of apo, MVAPP-bound, and ternary complex wild-type MDD provides structural information about the mode of substrate binding and the catalytic mechanism. Structural characterization of ternary complexes of catalytically deficient MDD S192A and D283A (k{sub cat} decreased 10{sup 3}- and 10{sup 5}-fold, respectively) provides insight into MDD function. The carboxylate side chain of invariant Asp{sup 283} functions as a catalytic base and is essential for the proper orientation of the MVAPP C3-hydroxyl group within the active site funnel. Several MDD amino acids within the conserved phosphate binding loop ('P-loop') provide key interactions, stabilizing the nucleotide triphosphoryl moiety. The crystal structures presented here provide a useful foundation for structure-based drug design.

  15. The neural substrates of response inhibition to negative information across explicit and implicit tasks in GAD patients: Electrophysiological evidence from an ERP study

    Fengqiong eYu

    2015-03-01

    Full Text Available Background: It has been established that the inability to inhibit a response to negative stimuli is the genesis of anxiety. However, the neural substrates of response inhibition to sad faces across explicit and implicit tasks in general anxiety disorder (GAD patients remain unclear.Methods: Electrophysiological data were recorded when subjects performed two modified emotional go/no-go tasks in which neutral and sad faces were presented: one task was explicit (emotion categorization, and the other task was implicit (gender categorization.Results: In the explicit task, electrophysiological evidence showed decreased amplitudes of no-go/go difference waves at the N2 interval in the GAD group compared to the control group. However, in the implicit task, the amplitudes of no-go/go difference waves at the N2 interval showed a reversed trend. Source localization analysis on no-go/N2 components revealed a decreased current source density (CSD in the right dorsal lateral prefrontal cortex in GAD individuals relative to controls. In the implicit task, the left superior temporal gyrus and the left inferior parietal lobe showed enhanced activation in GAD individuals and may compensate for the dysfunction of the right dorsal lateral prefrontal cortex.Conclusions: These findings indicated that the processing of response inhibition to socially sad faces in GAD individuals was interrupted in the explicit task. However, this processing was preserved in the implicit task. The neural substrates of response inhibition to sad faces were dissociated between implicit and explicit tasks.

  16. Variation in oxalate and oxalate decarboxylase production by six species of brown and white rot fungi

    Hastrup, Anne Christine Steenkjær; Oliver, Jason; Howell, Caitlin;

    cell lumen where it quickly dissociates into hydrogen ions and oxalate, resulting in a pH decrease of the environment, and oxalate-cation complexes. Generally, brown rot fungi accumulate larger quantities of oxalic acid in the wood than white rot fungi. The amount of oxalic acid has been shown to vary...... significantly among strains of brown rot fungi and within strains in response to differing environmental conditions (Green and Clausen; Hastrup et al., 2006).  This variation is in part believed to be due to the level of oxalate decarboxylase (ODC). The enzyme breaks down oxalate into stoichiometric quantities...... of formic acid and CO2 (Makela et al., 2002). So far only a few species of brown rot fungi have been shown to accumulate this enzyme (Micales, 1995, Howell and Jellison, 2006).   The purpose of this study was to investigate the variation in the levels of soluble oxalate and total oxalate, in...

  17. Uroporphyrinogen decarboxylase gene mutations in Danish patients with porphyria cutanea tarda

    Christiansen, L; Bygum, A; Jensen, A; Brandrup, F; Thomsen, K; Hørder, Mogens; Petersen, N E

    2000-01-01

    Decreased uroporphyrinogen decarboxylase (UROD) activity is a characteristic feature of the most common of the porphyrias, porphyria cutanea tarda (PCT). A subgroup of the clinically overt PCT cases is associated with mutations in the gene encoding UROD and inherited as an autosomal-dominant trait...

  18. Screening for mutations in the uroporphyrinogen decarboxylase gene using denaturing gradient gel electrophoresis

    Christiansen, L; Ged, C; Hombrados, I; Brons-Poulsen, J; Fontanellas, A; de Verneuil, H; Hørder, M; Petersen, N E

    1999-01-01

    The two porphyrias, familial porphyria cutanea tarda (fPCT) and hepatoerythropoietic porphyria (HEP), are associated with mutations in the gene encoding the enzyme uroporphyrinogen decarboxylase (UROD). Several mutations, most of which are private, have been identified in HEP and fPCT patients...

  19. Improving nutritional quality and fungal tolerance in soya bean and grass pea by expressing an oxalate decarboxylase.

    Kumar, Vinay; Chattopadhyay, Arnab; Ghosh, Sumit; Irfan, Mohammad; Chakraborty, Niranjan; Chakraborty, Subhra; Datta, Asis

    2016-06-01

    Soya bean (Glycine max) and grass pea (Lathyrus sativus) seeds are important sources of dietary proteins; however, they also contain antinutritional metabolite oxalic acid (OA). Excess dietary intake of OA leads to nephrolithiasis due to the formation of calcium oxalate crystals in kidneys. Besides, OA is also a known precursor of β-N-oxalyl-L-α,β-diaminopropionic acid (β-ODAP), a neurotoxin found in grass pea. Here, we report the reduction in OA level in soya bean (up to 73%) and grass pea (up to 75%) seeds by constitutive and/or seed-specific expression of an oxalate-degrading enzyme, oxalate decarboxylase (FvOXDC) of Flammulina velutipes. In addition, β-ODAP level of grass pea seeds was also reduced up to 73%. Reduced OA content was interrelated with the associated increase in seeds micronutrients such as calcium, iron and zinc. Moreover, constitutive expression of FvOXDC led to improved tolerance to the fungal pathogen Sclerotinia sclerotiorum that requires OA during host colonization. Importantly, FvOXDC-expressing soya bean and grass pea plants were similar to the wild type with respect to the morphology and photosynthetic rates, and seed protein pool remained unaltered as revealed by the comparative proteomic analysis. Taken together, these results demonstrated improved seed quality and tolerance to the fungal pathogen in two important legume crops, by the expression of an oxalate-degrading enzyme. PMID:26798990

  20. New enzymatic methods for selective assay of L-lysine using an L-lysine specific decarboxylase/oxidase from Burkholderia sp. AIU 395.

    Sugawara, Asami; Matsui, Daisuke; Yamada, Miwa; Asano, Yasuhisa; Isobe, Kimiyasu

    2015-03-01

    We developed new enzymatic methods for the selective assay of L-lysine by utilizing an oxidase reaction and a decarboxylation reaction by the L-lysine-specific decarboxylase/oxidase (L-Lys-DC/OD) from Burkholderia sp. AIU 395. The method utilizing the oxidase reaction of this enzyme was useful for determination of high concentrations of L-lysine. The method utilizing the decarboxylase reaction, which proceeded via the combination of the L-Lys-DC/OD and putrescine oxidase (PUO) from Micrococcus rubens, was effective for determination of low concentrations of L-lysine. Both methods showed good linearity, and neither was affected by other amino acids or amines. In addition, the within-assay and between-assay precisions of both methods were within the allowable range. The coupling of L-Lys-DC/OD with PUO was also useful for the differential assay of L-lysine and cadaverine. These newly developed methods were applied to the assay of L-lysine in biological samples and found to be effective. PMID:25282636

  1. Autoimmune disease

    2005-01-01

    2005164 Optimal cut-point of glutamic acid decar-boxylase antibody (GAD-Ab) for differentiating two subtypes of latent autoimmune diabetes in adults (LADA). LI Xia(李霞), et al. Dept Endocrinol, 2nd Xiangya Hosp, Central South Univ, Changsha, 410011. Chin J Diabetes, 2005;13(1) :34-38. Objective: To investigate the optimal cut-point of glutamate decarboxylase antibody (GAD-Ab) for differentiating two subtypes of latent autoimmune diabetes in adults (I. ADA). Methods: The frequency

  2. Gestos autolíticos deliberados (GAD en adolescentes en el Oeste de Londres: Factores socio-culturales

    Dinesh Bhugra

    2004-06-01

    Full Text Available Los estudios previos han sugerido que las tasas de gestos autolíticos deliberados (GAD en adolescentes asiáticos y pertenecientes a otros grupos étnicos minoritarios no son diferentes de aquéllas del grupo mayoritario. En este estudio documentamos los factores socio-culturales implicados en los gestos autolíticos llevados a cabo por los adolescentes del oeste de Londres durante un período de un año. Método. Se contactó con todos los casos de GAD en adolescentes para que participasen en el estudio. Empleando aproximaciones estándares y cualitativas, se recogieron los datos sobre los motivos del intento, identidad cultural y acontecimientos vitales. Resultados. Se identificaron un total de 76 casos durante un año. En contra de lo esperado, las tasas de intento de suicidio fueron más bajas en los asiáticos que en los blancos. Los patrones de intento de suicidio mostraron que la sobredosis fue el sistema más comúnmente empleado y que el factor precipitante más común, sin tener en cuenta la etnia, fue el desacuerdo con los padres. Las sobredosis fueron, en ambos grupos, de tipo impulsivo. Los asiáticos documentaron con mayor frecuencia conflictos culturales, incluso aunque las tasas en los dos grupos no son diferentes. Conclusiones. Cualquier estrategia preventiva debería incluir educación y ayuda para controlar el comportamiento impulsivo.

  3. 唾液链球菌嗜热亚种Y-2产谷氨酸脱羧酶的影响因子确立%Ascertainment of Factors Affecting Glutamate Decarboxylase Production by Streptococcus Salivarius ssp.thermophilus Y-2

    杨胜远; 陆兆新; 余勃; 林谦; 焦阳; 别小妹; 吕凤霞

    2008-01-01

    从产酶和细胞生长较好的MRS培养基出发,对Streptococcus salivarius ssp.thermophilus Y-2产谷氨酸脱羧酶(glutamate decarboxylase,GAD)的影响因子进行探讨,结果当培养基组成和培养条件为蛋白胨15g/L、牛肉膏12.5g/L、蔗糖12.5g/L、柠檬酸二铵2.0g/L、乙酸钠5.0g/L、K2HPO4 2.0g/L、CaCl2 2.0 g/L、Tween 80 1.0ml、pH7.0、接种量2%(V/V)、发酵温度37℃、发酵时间12h时,较有利于菌株Y-2产GAD.Plackett-Burman设计法研究表明培养基初始pH值和K2HPO4为影响菌株Y-2产GAD的主要影响因素.经对菌株Y-2产GAD影响因素的筛选,新获得的培养基在组成上与MRS培养基相比已发生显著变化,GAD活力提高了1.3倍.

  4. Distribution and ultrastructure of neurons in opossum piriform cortex displaying immunoreactivity to GABA and GAD and high-affinity tritiated GABA uptake

    GABAergic neurons have been identified in the piriform cortex of the opossum at light and electron microscopic levels by immunocytochemical localization of GABA and the GABA-synthesizing enzyme glutamic acid decarboxylase and by autoradiographic visualization of high-affinity 3H-GABA uptake. Four major neuron populations have been distinguished on the basis of soma size, shape, and segregation at specific depths and locations: large horizontal cells in layer Ia of the anterior piriform cortex, small globular cells with thin dendrites concentrated in layers Ib and II of the posterior piriform cortex, and multipolar and fusiform cells concentrated in the deep part of layer III in anterior and posterior parts of the piriform cortex and the subjacent endopiriform nucleus. All four populations were well visualized with both antisera, but the large layer Ia horizontal cells displayed only very light 3H-GABA uptake, thus suggesting a lack of local axon collaterals or lack of high-affinity GABA uptake sites. The large, ultrastructurally distinctive somata of layer Ia horizontal cells receive a very small number of symmetrical synapses; the thin, axonlike dendrites of small globular cells are exclusively postsynaptic and receive large numbers of both symmetrical and asymmetrical synapses, in contrast to somata which receive a small number of both types; and the deep multipolar and fusiform cells receive a highly variable number of symmetrical and asymmetrical synapses on somata and proximal dendrites. Labeled puncta of axon terminal dimensions were found in large numbers in the neuropil surrounding pyramidal cell somata in layer II and in the endopiriform nucleus. Moderately large numbers of labeled puncta were found in layer I at the depth of pyramidal cell apical dendrites with greater numbers in layer Ia at the depth of distal apical segments than in layer Ib

  5. Distribution and ultrastructure of neurons in opossum piriform cortex displaying immunoreactivity to GABA and GAD and high-affinity tritiated GABA uptake

    Haberly, L.B.; Hansen, D.J.; Feig, S.L.; Presto, S.

    1987-12-08

    GABAergic neurons have been identified in the piriform cortex of the opossum at light and electron microscopic levels by immunocytochemical localization of GABA and the GABA-synthesizing enzyme glutamic acid decarboxylase and by autoradiographic visualization of high-affinity /sup 3/H-GABA uptake. Four major neuron populations have been distinguished on the basis of soma size, shape, and segregation at specific depths and locations: large horizontal cells in layer Ia of the anterior piriform cortex, small globular cells with thin dendrites concentrated in layers Ib and II of the posterior piriform cortex, and multipolar and fusiform cells concentrated in the deep part of layer III in anterior and posterior parts of the piriform cortex and the subjacent endopiriform nucleus. All four populations were well visualized with both antisera, but the large layer Ia horizontal cells displayed only very light /sup 3/H-GABA uptake, thus suggesting a lack of local axon collaterals or lack of high-affinity GABA uptake sites. The large, ultrastructurally distinctive somata of layer Ia horizontal cells receive a very small number of symmetrical synapses; the thin, axonlike dendrites of small globular cells are exclusively postsynaptic and receive large numbers of both symmetrical and asymmetrical synapses, in contrast to somata which receive a small number of both types; and the deep multipolar and fusiform cells receive a highly variable number of symmetrical and asymmetrical synapses on somata and proximal dendrites. Labeled puncta of axon terminal dimensions were found in large numbers in the neuropil surrounding pyramidal cell somata in layer II and in the endopiriform nucleus. Moderately large numbers of labeled puncta were found in layer I at the depth of pyramidal cell apical dendrites with greater numbers in layer Ia at the depth of distal apical segments than in layer Ib.

  6. High-performance liquid chromatography method with radiochemical detection for measurement of nitric oxide synthase, arginase, and arginine decarboxylase activities.

    Volke, A; Wegener, G; Vasar, E; Volke, V

    2006-01-01

    Nitric oxide has been shown to be involved in numerous biological processes, and many studies have aimed to measure nitric oxide synthase (NOS) activity. Recently, it has been demonstrated that arginase and arginine decarboxylase (ADC), two enzymes that also employ arginine as a substrate, may regulate NOS activity. We aimed to develop a HPLC-based method to measure simultaneously the products of these three enzymes. Traditionally, the separation of amino acids and related compounds with HPLC has been carried out with precolumn derivatization and reverse phase chromatography. We describe here a simple and fast HPLC method with radiochemical detection to separate radiolabeled L-arginine, L-citrulline, L-ornithine, and agmatine. 3H-labeled L-arginine, L-citrulline, agmatine, and 14C-labeled L-citrulline were used as standards. These compounds were separated in the normal phase column (Allure Acidix 250 x 4.6 mm i.d.) under isocratic conditions in less than 20 min with good sensitivity. Using the current method, we have shown the formation of L-citrulline and L-ornithine in vitro using brain tissue homogenate of rats and that of agmatine by Escherichia coli ADC. PMID:16541190

  7. Accumulation of uroporphyrin does not provoke further inhibition of liver uroporphyrinogen decarboxylase activity in hexachlorobenzene-induced porphyria.

    Adjarov, D G; Elder, G H

    1986-01-01

    The inhibition of uroporphyrinogen decarboxylase (Uro-D) is the basic pathogenetic mechanism in porphyria caused by hexachlorobenzene (HCB). This study aimed to establish whether hepatic accumulation of uroporphyrin in this porphyria could provoke a further decrease of Uro-D activity. Male C57Bl/6 mice were treated for 8 weeks with a diet containing 0.02% HCB. In some of them the deposition of liver porphyrins was additionally increased by intraperitoneal application of delta-aminolaevulinic acid (ALA). Uro-D activity was determined by measuring unconverted substrate uroporphyrinogen after its oxidation to uroporphyrin by reversed-phase high performance liquid chromatography. The value of endogenously formed uroporphyrin was also obtained from the sample by subtraction, using a blank assay. HCB treatment resulted in reduced activity of hepatic Uro-D, but this activity was not significantly less in animals loaded with ALA than in non-loaded mice. Uroporphyrin deposition tended to decrease 6 weeks after withdrawal of HCB, but the activity of Uro-D was still markedly inhibited. There was no evidence that the accumulation of uroporphyrin promoted a supplementary decrease of Uro-D activity in HCB porphyria. PMID:3596742

  8. Real-Time kinetic studies of Bacillus subtilis oxalate decarboxylase and Ceriporiopsis subvermispora oxalate oxidase using a luminescent oxygen sensor

    Laura Molina

    2014-12-01

    Full Text Available Oxalate decarboxylase (OxDC, an enzyme of the bicupinsuperfamily, catalyzes the decomposition of oxalate into carbondioxide and formate at an optimal pH of 4.3 in the presence ofoxygen. However, about 0.2% of all reactions occur through anoxidase mechanism that consumes oxygen while producing twoequivalents of carbon dioxide and one equivalent of hydrogenperoxide. The kinetics of oxidase activity were studied bymeasuring the consumption of dissolved oxygen over time using a luminescent oxygen sensor. We describe the implementation of and improvements to the oxygen consumption assay. The oxidase activity of wild type OxDC was compared to that of the T165V OxDC mutant, which contains an impaired flexible loop covering the active site. The effects of various carboxylic acid-based buffers on the rate of oxidase activity were also studied. These results were compared to the oxidase activity of oxalate oxidase (OxOx, a similar bicupin enzyme that only carries out oxalate oxidation. Thetemperature dependence of oxidase activity was analyzed, andpreliminary results offer an estimate for the overall activationenergy of the oxidase reaction within OxDC. The data reported here thus provide insights into the mechanism of the oxidase activity of OxDC.

  9. Crystallization and preliminary X-ray analysis of the inducible lysine decarboxylase from Escherichia coli

    The structure of the decameric inducible lysine decarboxylase from E. coli was determined by SIRAS using a hexatantalum dodecabromide (Ta6Br122+) derivative. Model building and refinement are under way. The decameric inducible lysine decarboxylase (LdcI) from Escherichia coli has been crystallized in space groups C2 and C2221; the Ta6Br122+ cluster was used to derivatize the C2 crystals. The method of single isomorphous replacement with anomalous scattering (SIRAS) as implemented in SHELXD was used to solve the Ta6Br122+-derivatized structure to 5 Å resolution. Many of the Ta6Br122+-binding sites had twofold and fivefold noncrystallographic symmetry. Taking advantage of this feature, phase modification was performed in DM. The electron-density map of LdcI displays many features in agreement with the low-resolution negative-stain electron-density map [Snider et al. (2006 ▶), J. Biol. Chem.281, 1532–1546

  10. Deletion of glycine decarboxylase in arabidopsis is lethal under nonphotorespiratory conditions

    Engel, N.; van den Daele, K.; Kolukisaoglu, U.; Morgenthal, K.; Weckwerth, W.; Parnik, T.; Keerberg, O.; Bauwe, H.

    2007-01-01

    The mitochondrial multienzyme glycine decarboxylase (GDC) catalyzes the tetrahydrofolate-dependent catabolism of glycine to 5,10-methylene-tetrahydrofolate and the side products NADH, CO 2, and NH3. This reaction forms part of the photorespiratory cycle and contributes to one-carbon metabolism. While the important role of GDC for these two metabolic pathways is well established, the existence of bypassing reactions has also been suggested. Therefore, it is not clear to what extent GDC is obli...