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Sample records for 15-prostaglandin dehydrogenase expression

  1. Buformin suppresses the expression of glyceraldehyde 3-phosphate dehydrogenase.

    Science.gov (United States)

    Yano, Akiko; Kubota, Masafumi; Iguchi, Kazuhiro; Usui, Shigeyuki; Hirano, Kazuyuki

    2006-05-01

    The biguanides metformin and buformin, which are clinically used for diabetes mellitus, are known to improve resistance to insulin in patients. Biguanides were reported to cause lactic acidosis as a side effect. Since the mechanism of the side effect still remains obscure, we have examined genes whose expression changes by treating HepG2 cells with buformin in order to elucidate the mechanisms of the side effect. A subtraction cDNA library was constructed by the method of suppressive subtractive hybridization and the screening of the library was performed with cDNA probes prepared from HepG2 cells treated with or without buformin for 12 h. The expression of the gene and the protein obtained by the screening was monitored by real-time RT-PCR with specific primers and Western blotting with specific antibody. The amounts of ATP and NAD+ were determined with luciferase and alcohol dehydrogenase, respectively. We found that expression of the glyceraldehyde 3-phosphate dehydrogenase (GAPD) gene was suppressed by treating HepG2 cells with 0.25 mM buformin for 12 h as a result of the library screening. The decrease in the expression depended on the treatment period. The amount of GAPD protein also decreased simultaneously with the suppression of the gene expression by the treatment with buformin. The amount of ATP and NAD+ in the HepG2 cells treated with buformin decreased to 10 and 20% of the control, respectively. These observations imply that the biguanide causes deactivation of the glycolytic pathway and subsequently the accumulation of pyruvate and NADH and a decrease in NAD+. Therefore, the reaction equilibrium catalyzed by lactate dehydrogenase leans towards lactate production and this may result in lactic acidosis.

  2. Expression of lactate dehydrogenase C correlates with poor prognosis in renal cell carcinoma.

    Science.gov (United States)

    Hua, Yibo; Liang, Chao; Zhu, Jundong; Miao, Chenkui; Yu, Yajie; Xu, Aimin; Zhang, Jianzhong; Li, Pu; Li, Shuang; Bao, Meiling; Yang, Jie; Qin, Chao; Wang, Zengjun

    2017-03-01

    Lactate dehydrogenase C is an isoenzyme of lactate dehydrogenase and a member of the cancer-testis antigens family. In this study, we aimed to investigate the expression and functional role of lactate dehydrogenase C and its basic mechanisms in renal cell carcinoma. First, a total of 133 cases of renal cell carcinoma samples were analysed in a tissue microarray, and Kaplan-Meier survival curve analyses were performed to investigate the correlation between lactate dehydrogenase C expression and renal cell carcinoma progression. Lactate dehydrogenase C protein levels and messenger RNA levels were significantly upregulated in renal cell carcinoma tissues, and the patients with positive lactate dehydrogenase C expression had a shorter progression-free survival, indicating the oncogenic role of lactate dehydrogenase C in renal cell carcinoma. In addition, further cytological experiments demonstrated that lactate dehydrogenase C could prompt renal cell carcinoma cells to produce lactate, and increase metastatic and invasive potential of renal cell carcinoma cells. Furthermore, lactate dehydrogenase C could induce the epithelial-mesenchymal transition process and matrix metalloproteinase-9 expression. In summary, these findings showed lactate dehydrogenase C was associated with poor prognosis in renal cell carcinoma and played a pivotal role in the migration and invasion of renal cell carcinoma cells. Lactate dehydrogenase C may act as a novel biomarker for renal cell carcinoma progression and a potential therapeutic target for the treatment of renal cell carcinoma.

  3. The expression of succinate dehydrogenase in breast phyllodes tumor.

    Science.gov (United States)

    Choi, Junjeong; Kim, Do Hee; Jung, WooHee; Koo, Ja Seung

    2014-10-01

    The purpose of this study is to investigate the expression of succinate dehydrogenase (SDH)A, SDHB, and HIF-1α in phyllodes tumors and the association with clinic-pathologic factors. Using tissue microarray (TMA) for 206 phyllodes tumor cases, we performed immunohistochemical stains for SDHA, SDHB, and HIF-1α and analyzed their expression in regard to clinicopathologic parameters of each case. The cases were comprised of 156 benign, 34 borderline, and 16 malignant phyllodes tumors. The expression of stromal SDHA and epithelial- and stromal- SDHB increased as the tumor progressed from benign to malignant (P⟨0.001). There were five stromal SDHA-negative cases and 31 stromal SDHB-negative cases. SDHB negativity was associated with a lower histologic grade (P=0.054) and lower stromal atypia (P=0.048). Univariate analysis revealed that a shorter disease free survival (DFS) was associated with stromal SDHB high-positivity (P=0.013) and a shorter overall survival (OS) was associated with high-positivity of stromal SDHA and SDHB (P⟨0.001 and P⟨0.001, respectively). The multivariate Cox analysis with the variables stromal cellularity, stromal atypia, stromal mitosis, stromal overgrowth, tumor margin, stromal SDHA expression, and stromal SDHB expression revealed that stromal overgrowth was associated with a shorter DFS (hazard ratio: 24.78, 95% CI: 3.126-196.5, P=0.002) and a shorter OS (hazard ratio: 176.7, 95% CI: 8.466-3691, P=0.001). In conclusion, Tumor grade is positively correlated with SDHA and SDHB expression in the tumor stroma in phyllodes tumors of the breast. This result may be attributed to the increased metabolic demand in high grade tumors.

  4. Increased IMP dehydrogenase gene expression in solid tumor tissues and tumor cell lines

    Energy Technology Data Exchange (ETDEWEB)

    Collart, F.R.; Chubb, C.B.; Mirkin, B.L.; Huberman, E.

    1992-07-10

    IMP dehydrogenase, a regulatory enzyme of guanine nucleotide biosynthesis, may play a role in cell proliferation and malignancy. To assess this possibility, we examined IMP dehydrogenase expression in a series of human solid tumor tissues and tumor cell lines in comparison with their normal counterparts. Increased IMP dehydrogenase gene expression was observed in brain tumors relative to normal brain tissue and in sarcoma cells relative to normal fibroblasts. Similarly, in several B- and T-lymphoid leukemia cell lines, elevated levels of IMP dehydrogenase mRNA and cellular enzyme were observed in comparison with the levels in peripheral blood lymphocytes. These results are consistent with an association between increased IMP dehydrogenase expression and either enhanced cell proliferation or malignant transformation.

  5. Isolation, characterization and evaluation of the Pichia pastoris sorbitol dehydrogenase promoter for expression of heterologous proteins.

    Science.gov (United States)

    Periyasamy, Sankar; Govindappa, Nagaraj; Sreenivas, Suma; Sastry, Kedarnath

    2013-11-01

    Sorbitol is used as a non-repressive carbon source to develop fermentation process for Mut(s) recombinant clones obtained using the AOX1 promoter in Pichia pastoris. Sorbitol dehydrogenase is an enzyme in the carbohydrate metabolism that catalyzes reduction of D-fructose into D-sorbitol in the presence of NADH. The small stretch of 211bps upstream region of sorbitol dehydrogenase coding gene has all the promoter elements like CAAT box, GC box, etc. It is able to promote protein production under repressive as well as non-repressive carbon sources. In this study, the strength of the sorbitol dehydrogenase promoter was evaluated by expression of two heterologous proteins: human serum albumin and erythrina trypsin inhibitor. Sorbitol dehydrogenase promoter allowed constitutive expression of recombinant proteins in all carbon sources that were tested to grow P. pastoris and showed activity similar to GAP promoter. The sorbitol dehydrogenase promoter was active in all the growth phases of the P. pastoris.

  6. Expression, crystallization and preliminary X-ray crystallographic analysis of alcohol dehydrogenase (ADH) from Kangiella koreensis.

    Science.gov (United States)

    Ngo, Ho-Phuong-Thuy; Hong, Seung-Hye; Hong, Myoung-Ki; Pham, Tan-Viet; Oh, Deok-Kun; Kang, Lin-Woo

    2013-09-01

    Alcohol dehydrogenases (ADHs) are a group of dehydrogenase enzymes that facilitate the interconversion between alcohols and aldehydes or ketones with the reduction of NAD(+) to NADH. In bacteria, some alcohol dehydrogenases catalyze the opposite reaction as part of fermentation to ensure a constant supply of NAD(+). The adh gene from Kangiella koreensis was cloned and the protein (KkADH) was expressed, purified and crystallized. A KkADH crystal diffracted to 2.5 Å resolution and belonged to the monoclinic space group P2(1), with unit-cell parameters a = 94.1, b = 80.9, c = 115.6 Å, β = 111.9°. Four monomers were present in the asymmetric unit, with a corresponding VM of 2.55 Å(3) Da(-1) and a solvent content of 51.8%.

  7. Expression of aldehyde dehydrogenase 1 in colon cancer

    Institute of Scientific and Technical Information of China (English)

    Yi Hou; Yi-Yi Liu; Xiao-Kun Zhao

    2013-01-01

    Objective: To study the expression of ALDH1 in colon cancer and its clinical significance. Methods: The expression of ALDH1 was examined in 98 surgical specimens of primary colonic carcinoma and 15 normal colon tissues with immunohistochemistry method. The correlations of the expression with clinicopathological parameters and prognosis of colon cancer were analyzed.Results:The positive rate of expression of ALDH1 was 76.5% (75/98) in the cancer tissues and 13.3% (2/15) in normal colon tissues. There were an obvious statistical difference (P<0.05) between the two groups. The ALDH1 expression was significantly correlated with the histological grade, TNM stages and lymph node metastasis in colon cancer (P<0.05). It was also related with patients’ survival time, those with positive expressions had a poor prognosis (P<0.05). Conclusions: The results suggeste that the overexpression of ALDH1 plays important roles in proliferation and progression in colon cancer, the ALDH1 may be a valuable marker to predict the biological behavior and trend of metastasis of colon cancer.

  8. Molecular mechanism of null expression of aldehyde dehydrogenase-1 in rat liver

    Energy Technology Data Exchange (ETDEWEB)

    Chen, J.; Yoshida, Akira [Institute of the City of Hope, Duarte, CA (United States); Yanagawa, Yuchio [Tokohu Univ., Sendai (Japan)

    1996-04-01

    In isozyme systems in general, the pattern of tissue-dependent expression of a given type of isozyme is uniform in various mammalian species. In contrast, a major cytosolic aldehyde dehydrogenase isozyme, termed ALDH1, which is strongly expressed in the livers of humans and other mammals, is hardly detectable in rat liver. Thirteen nucleotides existing in the 5{prime}-promoter region of human, marmoset, and mouse ALDH1 genes are absent in the four rat strains examined. When the 13 nucleotides were deleted from a chloramphenicol acetyltransferase expression construct, which contained the 5{prime} promoter region of the human ALDH1 gene and a low-background promoterless chloramphenicol acetyltransferase expression vector, the expression activity was severely diminished in human hepatic cells. Thus, deletion of the 13 nucleotides in the promoter region of the gene can account for the lack of ALDH1 expression in rat liver. 16 refs., 3 figs.

  9. Expression, Purification, Crystallization And Preliminary X-Ray Studies of Histamine Dehydrogenase From Nocardioides Simplex

    Energy Technology Data Exchange (ETDEWEB)

    Reed, T.M.; Hirakawa, H.; Mure, M.; Scott, E.E.; Limburg, J.

    2009-05-21

    Histamine dehydrogenase (HADH) from Nocardioides simplex catalyzes the oxidative deamination of histamine to produce imidazole acetaldehyde and an ammonium ion. HADH is functionally related to trimethylamine dehydrogenase (TMADH), but HADH has strict substrate specificity towards histamine. HADH is a homodimer, with each 76 kDa subunit containing two redox cofactors: a [4Fe-4S] cluster and an unusual covalently bound flavin mononucleotide, 6-S-cysteinyl-FMN. In order to understand the substrate specificity of HADH, it was sought to determine its structure by X-ray crystallography. This enzyme has been expressed recombinantly in Escherichia coli and successfully crystallized in two forms. Diffraction data were collected to 2.7 {angstrom} resolution at the SSRL synchrotron with 99.7% completeness. The crystals belonged to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 101.14, b = 107.03, c = 153.35 {angstrom}.

  10. 11-Beta hydroxysteroid dehydrogenase type 2 expression in white adipose tissue is strongly correlated with adiposity.

    Science.gov (United States)

    Milagro, Fermin I; Campión, Javier; Martínez, J Alfredo

    2007-04-01

    Glucocorticoid action within the cells is regulated by the levels of glucocorticoid receptor (GR) expression and two enzymes, 11-beta hydroxysteroid dehydrogenase type 1 (11betaHSD1), which converts inactive to active glucocorticoids, and 11-beta hydroxysteroid dehydrogenase type 2 (11betaHSD2), which regulates the access of active glucocorticoids to the receptor by converting cortisol/corticosterone to the glucocorticoid-inactive form cortisone/dehydrocorticosterone. Male Wistar rats developed obesity by being fed a high-fat diet for 56 days, and GR, 11betaHSD1 and 11betaHSD2 gene expression were compared with control-diet fed animals. Gene expression analysis of 11betaHSD1, 11betaHSD2 and GR were performed by RT-PCR in subcutaneous and retroperitoneal adipose tissue. High-fat fed animals overexpressed 11betaHSD2 in subcutaneous but not in retroperitoneal fat. Interestingly, mRNA levels strongly correlated in both tissues with different parameters related to obesity, such as body weight, adiposity and insulin resistance, suggesting that this gene is a reliable marker of adiposity in this rat model of obesity. Thus, 11betaHSD2 is expressed in adipose tissue by both adipocytes and stromal-vascular cells, which suggests that this enzyme may play an important role in preventing fat accumulation in adipose tissue.

  11. Cloning, characterization and functional expression of Taenia solium 17 beta-hydroxysteroid dehydrogenase.

    Science.gov (United States)

    Aceves-Ramos, A; de la Torre, P; Hinojosa, L; Ponce, A; García-Villegas, R; Laclette, J P; Bobes, R J; Romano, M C

    2014-07-01

    The 17β-hydroxysteroid dehydrogenases (17β-HSD) are key enzymes involved in the formation (reduction) and inactivation (oxidation) of sex steroids. Several types have been found in vertebrates including fish, as well as in invertebrates like Caenorhabditis elegans, Ciona intestinalis and Haliotis diversicolor supertexta. To date limited information is available about this enzyme in parasites. We showed previously that Taenia solium cysticerci are able to synthesize sex steroid hormones in vitro when precursors are provided in the culture medium. Here, we identified a T. solium 17β-HSD through in silico blast searches in the T. solium genome database. This coding sequence was amplified by RT-PCR and cloned into the pcDNA 3.1(+) expression vector. The full length cDNA contains 957bp, corresponding to an open reading frame coding for 319 aa. The highest identity (84%) at the protein level was found with the Echinococcus multilocularis 17β-HSD although significant similarities were also found with other invertebrate and vertebrate 17β-HSD sequences. The T. solium Tsol-17βHSD belongs to the short-chain dehydrogenase/reductase (SDR) protein superfamily. HEK293T cells transiently transfected with Tsol17β-HSD induced expression of Tsol17β-HSD that transformed 3H-androstenedione into testosterone. In contrast, 3H-estrone was not significantly transformed into estradiol. In conclusion, T. solium cysticerci express a 17β-HSD that catalyzes the androgen reduction. The enzyme belongs to the short chain dehydrogenases/reductase family and shares motifs and activity with the type 3 enzyme of some other species.

  12. 20 alpha-hydroxysteroid dehydrogenase expression in a murine virus-induced myeloproliferative syndrome.

    Science.gov (United States)

    Marcovistz, R; Le Bousse-Kerdiles, M C; Maillere, B; Smadja-Joffe, F; Poirrier, V; Jasmin, C

    1991-11-01

    The myeloproliferative sarcoma virus (MPSV) infection in DBA/2 mice leads to important quantitative and qualitative changes in their hemopoiesis. These findings suggest a disturbance in the production and action of a certain hemopoietic factor similar to IL3. Here, we show that the level of the 20 alpha-hydroxysteroid dehydrogenase (20 alpha-SDH) expression, which can be induced by IL3, is dramatically increased in spleen and thymus of MPSV-infected mice. Our results suggest that quantification of 20 alpha-SDH activity can be used to indicate abnormal production of a growth factor similar to IL3 in hemopoietic system diseases.

  13. Microsatellite instability in colorectal cancer and association with thymidylate synthase and dihydropyrimidine dehydrogenase expression

    DEFF Research Database (Denmark)

    Jensen, Søren A; Vainer, Ben; Kruhøffer, Mogens;

    2009-01-01

    unclarified. The association of MSI and MMR status with outcome and with thymidylate synthase (TS) and dihydropyrimidine dehydrogenase (DPD) expression in colorectal cancer were evaluated. METHODS: MSI in five reference loci, MMR enzymes (hMSH2, hMSH6, hMLH1 and hPMS2), thymidylate synthase (TS......) and dihydropyrimidine dehydrogenase (DPD) expression were assessed in paraffin embedded tumor specimens, and associated with outcome in 340 consecutive patients completely resected for colorectal cancer stages II-IV and subsequently receiving adjuvant 5-fluorouracil therapy. RESULTS: MSI was found in 43 (13.8%) tumors...... ratio (HR) = 0.3; 95% CI: 0.2-0.7; P = 0.0007) and death (HR = 0.4; 95% CI: 0.2-0.9; P = 0.02) independently of the TS and DPD expressions. A direct relationship between MSI and TS intensity (P = 0.001) was found, while there was no significant association with DPD intensity (P = 0.1). CONCLUSION...

  14. Expression of Lactate Dehydrogenase in Aspergillus niger for L-Lactic Acid Production.

    Science.gov (United States)

    Dave, Khyati K; Punekar, Narayan S

    2015-01-01

    Different engineered organisms have been used to produce L-lactate. Poor yields of lactate at low pH and expensive downstream processing remain as bottlenecks. Aspergillus niger is a prolific citrate producer and a remarkably acid tolerant fungus. Neither a functional lactate dehydrogenase (LDH) from nor lactate production by A. niger is reported. Its genome was also investigated for the presence of a functional ldh. The endogenous A. niger citrate synthase promoter relevant to A. niger acidogenic metabolism was employed to drive constitutive expression of mouse lactate dehydrogenase (mldhA). An appraisal of different branches of the A. niger pyruvate node guided the choice of mldhA for heterologous expression. A high copy number transformant C12 strain, displaying highest LDH specific activity, was analyzed under different growth conditions. The C12 strain produced 7.7 g/l of extracellular L-lactate from 60 g/l of glucose, in non-neutralizing minimal media. Significantly, lactate and citrate accumulated under two different growth conditions. Already an established acidogenic platform, A. niger now promises to be a valuable host for lactate production.

  15. Microsatellite instability in colorectal cancer and association with thymidylate synthase and dihydropyrimidine dehydrogenase expression

    Directory of Open Access Journals (Sweden)

    Kruhøffer Mogens

    2009-01-01

    Full Text Available Abstract Background Microsatellite instability (MSI refers to mutations in short motifs of tandemly repeated nucleotides resulting from replication errors and deficient mismatch repair (MMR. Colorectal cancer with MSI has characteristic biology and chemosensitivity, however the molecular basis remains unclarified. The association of MSI and MMR status with outcome and with thymidylate synthase (TS and dihydropyrimidine dehydrogenase (DPD expression in colorectal cancer were evaluated. Methods MSI in five reference loci, MMR enzymes (hMSH2, hMSH6, hMLH1 and hPMS2, thymidylate synthase (TS and dihydropyrimidine dehydrogenase (DPD expression were assessed in paraffin embedded tumor specimens, and associated with outcome in 340 consecutive patients completely resected for colorectal cancer stages II-IV and subsequently receiving adjuvant 5-fluorouracil therapy. Results MSI was found in 43 (13.8% tumors. Absence of repair protein expression was assessed in 52 (17.0% tumors, which had primarily lost hMLH1 in 39 (12.7%, hMSH2 in 5 (1.6%, and hMSH6 in 8 (2.6% tumors. In multivariate analysis MSI (instable compared to MSS (stable tumors were significantly associated with lower risk of recurrence (hazard ratio (HR = 0.3; 95% CI: 0.2–0.7; P = 0.0007 and death (HR = 0.4; 95% CI: 0.2–0.9; P = 0.02 independently of the TS and DPD expressions. A direct relationship between MSI and TS intensity (P = 0.001 was found, while there was no significant association with DPD intensity (P = 0.1. Conclusion The favourable outcome of MSI colorectal carcinomas is ascribed mainly to the tumor biology and to a lesser extent to antitumor response to 5-fluorouracil therapy. There is no evidence that differential TS or DPD expression may account for these outcome characteristics.

  16. Enantioselective bioconversion using Escherichia coli cells expressing Saccharomyces cerevisiae reductase and Bacillus subtilis glucose dehydrogenase.

    Science.gov (United States)

    Park, Hyun Joo; Jung, Jihye; Choi, Hyejeong; Uhm, Ki-Nam; Kim, Hyung Kwoun

    2010-09-01

    Ethyl (R, S)-4-chloro-3-hydroxybutanoate (ECHB) is a useful chiral building block for the synthesis of L-carnitine and hypercholesterolemia drugs. The yeast reductase, YOL151W (GenBank locus tag), exhibits an enantioselective reduction activity, converting ethyl-4-chlorooxobutanoate (ECOB) exclusively into (R)-ECHB. YOL151W was generated in Escherichia coli cells and purified via Ni- NTA and desalting column chromatography. It evidenced an optimum temperature of 45 degrees C and an optimum pH of 6.5-7.5. Bacillus subtilis glucose dehydrogenase (GDH) was also expressed in Escherichia coli, and was used for the recycling of NADPH, required for the reduction reaction. Thereafter, Escherichia coli cells co-expressing YOL151W and GDH were constructed. After permeablization treatment, the Escherichia coli whole cells were utilized for ECHB synthesis. Through the use of this system, the 30 mM ECOB substrate could be converted to (R)-ECHB.

  17. The human L-threonine 3-dehydrogenase gene is an expressed pseudogene

    Directory of Open Access Journals (Sweden)

    Edgar Alasdair J

    2002-10-01

    Full Text Available Abstract Background L-threonine is an indispensable amino acid. One of the major L-threonine degradation pathways is the conversion of L-threonine via 2-amino-3-ketobutyrate to glycine. L-threonine dehydrogenase (EC 1.1.1.103 is the first enzyme in the pathway and catalyses the reaction: L-threonine + NAD+ = 2-amino-3-ketobutyrate + NADH. The murine and porcine L-threonine dehydrogenase genes (TDH have been identified previously, but the human gene has not been identified. Results The human TDH gene is located at 8p23-22 and has 8 exons spanning 10 kb that would have been expected to encode a 369 residue ORF. However, 2 cDNA TDH transcripts encode truncated proteins of 157 and 230 residues. These truncated proteins are the result of 3 mutations within the gene. There is a SNP, A to G, present in the genomic DNA sequence of some individuals which results in the loss of the acceptor splice site preceding exon 4. The acceptor splice site preceding exon 6 was lost in all 23 individuals genotyped and there is an in-frame stop codon in exon 6 (CGA to TGA resulting in arginine-214 being replaced by a stop codon. These truncated proteins would be non-functional since they have lost part of the NAD+ binding motif and the COOH terminal domain that is thought to be involved in binding L-threonine. TDH mRNA was present in all tissues examined. Conclusions The human L-threonine 3-dehydrogenase gene is an expressed pseudogene having lost the splice acceptor site preceding exon 6 and codon arginine-214 (CGA is mutated to a stop codon (TGA.

  18. Cloning, expression, functional validation and modeling of cinnamyl alcohol dehydrogenase isolated from xylem of Leucaena leucocephala.

    Science.gov (United States)

    Pandey, Brijesh; Pandey, Veda Prakash; Dwivedi, Upendra Nath

    2011-10-01

    A cDNA encoding cinnamyl alcohol dehydrogenase (CAD), catalyzing conversion of cinnamyl aldehydes to corresponding cinnamyl alcohols, was cloned from secondary xylem of Leucaena leucocephala. The cloned cDNA was expressed in Escherichia coli BL21 (DE3) pLysS cells. Temperature and Zn(2+) ion played crucial role in expression and activity of enzyme, such that, at 18°C and at 2 mM Zn(2+) the CAD was maximally expressed as active enzyme in soluble fraction. The expressed protein was purified 14.78-folds to homogeneity on Ni-NTA agarose column with specific activity of 346 nkat/mg protein. The purified enzyme exhibited lowest Km with cinnamyl alcohol (12.2 μM) followed by coniferyl (18.1 μM) and sinapyl alcohol (23.8 μM). Enzyme exhibited high substrate inhibition with cinnamyl (beyond 20 μM) and coniferyl (beyond 100 μM) alcohols. The in silico analysis of CAD protein exhibited four characteristic consensus sequences, GHEXXGXXXXXGXXV; C(100), C(103), C(106), C(114); GXGXXG and C(47), S(49), H(69), L(95), C(163), I(300) involved in catalytic Zn(2+) binding, structural Zn(2+) binding, NADP(+) binding and substrate binding, respectively. Tertiary structure, generated using Modeller 9v5, exhibited a trilobed structure with bulged out structural Zn(2+) binding domain. The catalytic Zn(2+) binding, substrate binding and NADP(+) binding domains formed a pocket protected by two major lobes. The enzyme catalysis, sequence homology and 3-D model, all supported that the cloned CAD belongs to alcohol dehydrogenase family of plants.

  19. Expression, purification and crystallization of Trypanosoma cruzi dihydroorotate dehydrogenase complexed with orotate

    Energy Technology Data Exchange (ETDEWEB)

    Inaoka, Daniel Ken; Takashima, Eizo; Osanai, Arihiro; Shimizu, Hironari [Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan); Nara, Takeshi; Aoki, Takashi [Department of Parasitology, Juntendo University, 2-1-1 Hongo, Bunkyo-ku, Tokyo 113-8421 (Japan); Harada, Shigeharu [Department of Applied Biology, Kyoto Institute of Technology, Sakyo-ku, Kyoto 606-8585 (Japan); Kita, Kiyoshi, E-mail: kitak@m.u-tokyo.ac.jp [Department of Biomedical Chemistry, Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033 (Japan)

    2005-10-01

    The Trypanosoma cruzi dihydroorotate dehydrogenase, a key enzyme in pyrimidine de novo biosynthesis and redox homeostasis, was crystallized in complex with its first reaction product, orotate. Dihydroorotate dehydrogenase (DHOD) catalyzes the oxidation of dihydroorotate to orotate, the fourth step and the only redox reaction in the de novo biosynthesis of pyrimidine. DHOD from Trypanosoma cruzi (TcDHOD) has been expressed as a recombinant protein in Escherichia coli and purified to homogeneity. Crystals of the TcDHOD–orotate complex were grown at 277 K by the sitting-drop vapour-diffusion technique using polyethylene glycol 3350 as a precipitant. The crystals diffract to better than 1.8 Å resolution using synchrotron radiation (λ = 0.900 Å). X-ray diffraction data were collected at 100 K and processed to 1.9 Å resolution with 98.2% completeness and an overall R{sub merge} of 7.8%. The TcDHOD crystals belong to the orthorhombic space group P2{sub 1}2{sub 1}2{sub 1}, with unit-cell parameters a = 67.87, b = 71.89, c = 123.27 Å. The presence of two molecules in the asymmetric unit (2 × 34 kDa) gives a crystal volume per protein weight (V{sub M}) of 2.2 Å{sup 3} Da{sup −1} and a solvent content of 44%.

  20. Roles of histamine on the expression of aldehyde dehydrogenase 1 in endometrioid adenocarcinoma cell line.

    Science.gov (United States)

    Wang, Yi; Jiang, Yang; Ikeda, Jun-Ichiro; Tian, Tian; Sato, Atsushi; Ohtsu, Hiroshi; Morii, Eiichi

    2014-10-01

    Cancer-initiating cells (CICs) are a limited number of cells that are essential for maintenance, recurrence, and metastasis of tumors. Aldehyde dehydrogenase 1 (ALDH1) has been recognized as a marker of CICs. We previously reported that ALDH1-high cases of uterine endometrioid adenocarcinoma showed poor prognosis, and that ALDH1 high population was more tumorigenic, invasive, and resistant to apoptosis than ALDH1 low population. Histamine plays a critical role in cancer cell proliferation, migration, and invasion. Here, we examined the effect of histamine on ALDH1 expression in endometrioid adenocarcinoma cell line. The addition of histamine increased ALDH1 high population, which was consistent with the result that histamine enhanced the invasive ability and the resistance to anticancer drug. Among 4 types of histamine receptors, histamine H1 and H2 receptor (H1R and H2R) were expressed in endometrioid adenocarcinoma cell line. The addition of H1R agonist but not H2R agonist increased ALDH1. The antagonist H1R but not H2R inhibited the effect of histamine on ALDH1 expression. These results indicated that histamine increased the expression of ALDH1 via H1R but not H2R. These findings may provide the evidence for exploring a new strategy to suppress CICs by inhibiting ALDH1 expression with histamine.

  1. Succinate Dehydrogenase B Subunit Immunohistochemical Expression Predicts Aggressiveness in Well Differentiated Neuroendocrine Tumors of the Ileum

    Energy Technology Data Exchange (ETDEWEB)

    Milione, Massimo [Department of Pathology and Laboratory Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan I-20133 (Italy); Pusceddu, Sara [Department of Medical Oncology, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan I-20133 (Italy); Gasparini, Patrizia [Molecular Cytogenetics Unit, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan I-20133 (Italy); Melotti, Flavia [Department of Pathology and Laboratory Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan I-20133 (Italy); Maisonneuve, Patrick [Division of Epidemiology and Biostatistics, European Institute of Oncology, Milan 20141 (Italy); Mazzaferro, Vincenzo [Division of Gastrointestinal Surgery and Liver Transplantation, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan I-20133 (Italy); Braud, Filippo G. de [Department of Medical Oncology, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan I-20133 (Italy); Pelosi, Giuseppe, E-mail: giuseppe.pelosi@unimi.it [Department of Pathology and Laboratory Medicine, Fondazione IRCCS Istituto Nazionale dei Tumori, Milan I-20133 (Italy); Department of Medicine, Surgery and Dentistry, Università degli Studi, Facoltà di Medicina, Milan 20122 (Italy)

    2012-08-16

    Immunohistochemical loss of the succinate dehydrogenase subunit B (SDHB) has recently been reported as a surrogate biomarker of malignancy in sporadic and familial pheocromocytomas and paragangliomas through the activation of hypoxia pathways. However, data on the prevalence and the clinical implications of SDHB immunoreactivity in ileal neuroendocrine tumors are still lacking. Thirty-one consecutive, advanced primary midgut neuroendocrine tumors and related lymph node or liver metastases from 24 males and seven females were immunohistochemically assessed for SDHB. All patients were G1 tumors (Ki-67 labeling index ≤2%). SDHB immunohistochemistry results were expressed as immunostaining intensity and scored as low or strong according to the internal control represented by normal intestinal cells. Strong positivity for SDHB, with granular cytoplasmatic reactivity, was found in 77% of primary tumors (T), whilst low SDHB expression was detected in 90% of metastases (M). The combined analysis (T+M) confirmed the loss of SDHB expression in 82% of metastases compared to 18% of primary tumors. SDHB expression was inversely correlated with Ki-67 labeling index, which accounted for 1.54% in metastastic sites and 0.7% in primary tumors. A correlation between SDHB expression loss, increased Ki-67 labeling index and biological aggressiveness was shown in advanced midgut neuroendocrine tumors, suggesting a role of tumor suppressor gene.

  2. Expression of betaine aldehyde dehydrogenase gene and salinity tolerance in rice transgenic plants

    Institute of Scientific and Technical Information of China (English)

    郭岩; 张莉; 肖岗; 曹守云; 谷冬梅; 田文忠; 陈受宜

    1997-01-01

    Betaine as one of osmolytes plays an important role in osmoregulation of most high plants. Betaine aldehyde dehydrogenase C BADH) is the second enzyme involved in betaine biosynthesis. The BADH gene from a halophite, Atriplex hortensis, was transformed into rice cultivars by bombarment method. Totally 192 transgenic rice plants were obtained and most of them had higher salt tolerance than controls. Among transgenic plants transplanted in the saline pool containing 0.5% NaCl in a greenhouse, 22 survived, 13 of which set seeds, and the frequency of seed setting was very low, only 10% . But the controls could not grow under the same condition. The results of BADH ac-tivity assay and Northern blot showed that the BADH gene was integrated into chromosomes of transgenic plants and expressed.

  3. Neurospora NADP-glutamate dehydrogenases and its expression in E. coli and transgenic plants

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Genes of NADP-glutamate dehydrogenase (NADP-GDH) were cloned from Neurospora intermedia (Ni), N. crassa (Nc), and N. sitophila (Ns). The sequences showed a high degree of homology at the cDNA and protein level. The three GDH genes were cloned into pET30a and expressed in E. coli. The activity assay of purified GDH showed that the Ni-GDH had a higher activity and affinity to ammonia than Ns-GDH, and Nc-GDH. The Km value of Ni-GDH ranges from 0.3 to 0.45 mmol/L. Ni-gdh gene was transformed to Nicotiana bethamiana plants. The transformed plants grew much better in low nitrogen media than the only ROKII vector transformed control.

  4. Decreased expression of pyruvate dehydrogenase A1 predicts an unfavorable prognosis in ovarian carcinoma

    Science.gov (United States)

    Li, Yaqing; Huang, Ruixia; Li, Xiaoli; Li, Xiaoran; Yu, Dandan; Zhang, Mingzhi; Wen, Jianguo; Goscinski, Mariusz Adam; Trope, Claes G; Nesland, Jahn M; Suo, Zhenhe

    2016-01-01

    Pyruvate dehydrogenase A1 (PDHA1) serves as a gate-keeper enzyme link between glycolysis and the mitochondrial citric acid cycle. The inhibition of PDHA1 in cancer cells can result in an increased Warburg effect and a more aggressive phenotype in cancer cells. This study was conducted to investigate the expression of PDHA1 in ovarian cancer and the correlation between PDHA1 expression and the prognosis of patients. The PDHA1 protein expression in 3 ovarian cancer cell lines (OVCAR-3, SKOV-3 and ES-2) and 248 surgically removed ovarian carcinoma samples was immunocytochemically examined. Statistical analyses were performed to evaluate the correlations between PDHA1 expression and the clinicopathological characteristics of the patients as well as the predictive value of PDHA1. The results showed the presence of variable expression of PDHA1 in the three ovarian cancer cell lines. Of the 248 ovarian cancer tissue specimens, 45 cases (18.1%) were negative in tumor cells for PDHA1, 162 cases (65.3%) displayed a low expression level, and 41 cases (16.5%) had a relatively high PDHA1 staining. The expression of PDHA1 was associated with the histological subtype (P=0.004) and FIGO stage (P=0.002). The median OS time in the PDHA1 negative group, low expression group and high expression group were 0.939 years, 1.443 years and 9.900 years, respectively. The median PFS time in the above three groups were 0.287 years, 0.586 years and 9.900 years, respectively. Furthermore, the high expression of PDHA1 in ovarian carcinoma cells was significantly associated with better OS and PFS by statistical analyses. Multivariate analyses showed that PDHA1 expression was also an independent prognostic factor for higher OS in ovarian cancer patients (HR=0.705, 95% CI 0.541-0.918, P=0.01). Our study indicated that the decreased expression of PDHA1 might be an independent prognostic factor in unfavorable outcomes. PMID:27725912

  5. The Alcohol Dehydrogenase Gene Family in Melon (Cucumis melo L.: Bioinformatic Analysis and Expression Patterns

    Directory of Open Access Journals (Sweden)

    Yazhong eJin

    2016-05-01

    Full Text Available Alcohol dehydrogenases (ADH, encoded by multigene family in plants, play a critical role in plant growth, development, adaptation, fruit ripening and aroma production. Thirteen ADH genes were identified in melon genome, including 12 ADHs and one formaldehyde dehydrogenease (FDH, designated CmADH1-12 and CmFDH1, in which CmADH1 and CmADH2 have been isolated in Cantaloupe. ADH genes shared a lower identity with each other at the protein level and had different intron-exon structure at nucleotide level. No typical signal peptides were found in all CmADHs, and CmADH proteins might locate in the cytoplasm. The phylogenetic tree revealed that 13 ADH genes were divided into 3 groups respectively, namely long-, medium- and short-chain ADH subfamily, and CmADH1,3-11, which belongs to the medium-chain ADH subfamily, fell into 6 medium-chain ADH subgroups. CmADH12 may belong to the long-chain ADH subfamily, while CmFDH1 may be a Class III ADH and serve as an ancestral ADH in melon. Expression profiling revealed that CmADH1, CmADH2, CmADH10 and CmFDH1 were moderately or strongly expressed in different vegetative tissues and fruit at medium and late developmental stages, while CmADH8 and CmADH12 were highly expressed in fruit after 20 days. CmADH3 showed preferential expression in young tissues. CmADH4 only had slight expression in root. Promoter analysis revealed several motifs of CmADH genes involved in the gene expression modulated by various hormones, and the response pattern of CmADH genes to ABA, IAA and ethylene were different. These CmADHs were divided into ethylene-sensitive and –insensitive groups, and the functions of CmADHs were discussed.

  6. 7-Ketocholesterol inhibits isocitrate dehydrogenase 2 expression and impairs endothelial function via microRNA-144.

    Science.gov (United States)

    Fu, Xiaodong; Huang, Xiuwei; Li, Ping; Chen, Weiyu; Xia, Min

    2014-06-01

    Oxysterol is associated with the induction of endothelial oxidative stress and impaired endothelial function. Mitochondria play a central role in oxidative energy metabolism and the maintenance of proper redox status. The purpose of this study was to determine the effects and mechanisms of 7-ketocholesterol (7-KC) on isocitrate dehydrogenase 2 (IDH2) and its impact on endothelial function in both human aortic endothelial cells (HAECs) and C57BL/6J mice. HAECs treated with 7-KC showed significant reductions of IDH2 mRNA and protein levels and enzyme activity, leading to decreased NADPH concentration and an increased ratio of reduced-to-oxidized glutathione in the mitochondria. 7-KC induced the expression of a specific microRNA, miR-144, which in turn targets and downregulates IDH2. In silico analysis predicted that miR-144 could bind to the 3'-untranslated region of IDH2 mRNA. Overexpression of miR-144 decreased the expression of IDH2 and the levels of NADPH. A complementary finding is that a miR-144 inhibitor increased the mRNA and protein expression levels of IDH2. Furthermore, miR-144 level was elevated in HAECs in response to 7-KC. Anti-Ago1/2 immunoprecipitation coupled with a real-time polymerase chain reaction assay revealed that 7-KC increased the functional targeting of miR-144/IDH2 mRNA in HAECs. Infusion of 7-KC in vivo decreased vascular IDH2 expression and impaired vascular reactivity via miR-144. 7-KC controls miR-144 expression, which in turn decreases IDH2 expression and attenuates NO bioavailability to impair endothelial homeostasis. The newly identified 7-KC-miR-144-IDH2 pathway may contribute to atherosclerosis progression and provides new insight into 7-KC function and microRNA biology in cardiovascular disease.

  7. Cloning, expression and characterization of alcohol dehydrogenases in the silkworm Bombyx mori

    Directory of Open Access Journals (Sweden)

    Nan Wang

    2011-01-01

    Full Text Available Alcohol dehydrogenases (ADH are a class of enzymes that catalyze the reversible oxidation of alcohols to corresponding aldehydes or ketones, by using either nicotinamide adenine dinucleotide (NAD or nicotinamide adenine dinucleotide phosphate (NADP, as coenzymes. In this study, a short-chain ADH gene was identified in Bombyx mori by 5'-RACE PCR. This is the first time the coding region of BmADH has been cloned, expressed, purified and then characterized. The cDNA fragment encoding the BmADH protein was amplified from a pool of silkworm cDNAs by PCR, and then cloned into E. coli expression vector pET-30a(+. The recombinant His-tagged BmADH protein was expressed in E. coli BL21 (DE3, and then purified by metal chelating affinity chromatography. The soluble recombinant BmADH, produced at low-growth temperature, was instrumental in catalyzing the ethanol-dependent reduction of NAD+, thereby indicating ethanol as one of the substrates of BmADH.

  8. Characterization of Cardiac-Resident Progenitor Cells Expressing High Aldehyde Dehydrogenase Activity

    Directory of Open Access Journals (Sweden)

    Marc-Estienne Roehrich

    2013-01-01

    Full Text Available High aldehyde dehydrogenase (ALDH activity has been associated with stem and progenitor cells in various tissues. Human cord blood and bone marrow ALDH-bright (ALDHbr cells have displayed angiogenic activity in preclinical studies and have been shown to be safe in clinical trials in patients with ischemic cardiovascular disease. The presence of ALDHbr cells in the heart has not been evaluated so far. We have characterized ALDHbr cells isolated from mouse hearts. One percent of nonmyocytic cells from neonatal and adult hearts were ALDHbr. ALDHvery-br cells were more frequent in neonatal hearts than adult. ALDHbr cells were more frequent in atria than ventricles. Expression of ALDH1A1 isozyme transcripts was highest in ALDHvery-br cells, intermediate in ALDHbr cells, and lowest in ALDHdim cells. ALDH1A2 expression was highest in ALDHvery-br cells, intermediate in ALDHdim cells, and lowest in ALDHbr cells. ALDH1A3 and ALDH2 expression was detectable in ALDHvery-br and ALDHbr cells, unlike ALDHdim cells, albeit at lower levels compared with ALDH1A1 and ALDH1A2. Freshly isolated ALDHbr cells were enriched for cells expressing stem cell antigen-1, CD34, CD90, CD44, and CD106. ALDHbr cells, unlike ALDHdim cells, could be grown in culture for more than 40 passages. They expressed sarcomeric α-actinin and could be differentiated along multiple mesenchymal lineages. However, the proportion of ALDHbr cells declined with cell passage. In conclusion, the cardiac-derived ALDHbr population is enriched for progenitor cells that exhibit mesenchymal progenitor-like characteristics and can be expanded in culture. The regenerative potential of cardiac-derived ALDHbr cells remains to be evaluated.

  9. Heterologous expression of Pycnoporus cinnabarinus cellobiose dehydrogenase in Pichia pastoris and involvement in saccharification processes

    Directory of Open Access Journals (Sweden)

    Bey Mathieu

    2011-12-01

    Full Text Available Abstract Background Cellobiose dehydrogenase (CDH is an extracellular hemoflavoenzyme produced by lignocellulose-degrading fungi including Pycnoporus cinnabarinus. We investigated the cellulolytic system of P. cinnabarinus, focusing on the involvement of CDH in the deconstruction of lignocellulosic biomass. Results First, P. cinnabarinus growth conditions were optimized for CDH production. Following growth under cellulolytic conditions, the main components secreted were cellulases, xylanases and CDH. To investigate the contribution of P. cinnabarinus secretome in saccharification processes, the Trichoderma reesei enzymatic cocktail was supplemented with the P. cinnabarinus secretome. A significant enhancement of the degradation of wheat straw was observed with (i the production of a large amount of gluconic acid, (ii increased hemicellulose degradation, and (iii increased overall degradation of the lignocellulosic material. P. cinnabarinus CDH was heterologously expressed in Pichia pastoris to obtain large amounts of pure enzyme. In a bioreactor, the recombinant CDH (rCDH expression level reached 7800 U/L. rCDH exhibited values of biochemical parameters similar to those of the natural enzyme, and was able to bind cellulose despite the absence of a carbohydrate-binding module (CBM. Following supplementation of purified rCDH to T. reesei enzymatic cocktail, formation of gluconic acid and increased hemicellulose degradation were observed, thus confirming the previous results observed with P. cinnabarinus secretome. Conclusions We demonstrate that CDH offers an attractive tool for saccharification process enhancement due to gluconic acid production from raw lignocellulosic material.

  10. Organ-specific expression of glutamate dehydrogenase (GDH) subunits in yellow lupine.

    Science.gov (United States)

    Lehmann, Teresa; Dabert, Mirosława; Nowak, Witold

    2011-07-01

    Glutamate dehydrogenase (GDH, EC 1.4.2-4) is present in yellow lupine (Lupinus luteus cv. Juno) in many isoforms. The number and banding pattern of isoenzymes varies with respect to plant organ and developmental stage. To better understand the complex nature of GDH regulation in plants, the levels of GDH transcripts, enzyme activity and isoenzyme patterns in germinating seeds and roots of yellow lupine were examined. The analysis of GDH cDNA sequences in lupine revealed three mRNA types, of which two encoded the β-GDH subunit and one encoded the α-GDH subunit (corresponding to the GDH1(GDH3) and GDH2 genes, respectively). The relative expression of GDH1 and GDH2 genes was analyzed in various lupine organs by using quantitative real-time PCR. Our results indicate that different mRNA types were differently regulated depending on organ type. Although both genes appeared to be ubiquitously expressed in all lupine tissues, the GDH1 transcripts evidently predominated over those of GDH2. Immunochemical analyses confirmed that, during embryo development, varied expression of two GDH subunits takes place. The α-GDH subunit (43kDa) predominated in the early stages of germinating seeds, while the β-GDH subunit (44kDa) was the only GDH polypeptide present in lupine roots. These results firmly support the hypothesis that isoenzyme variability of GDH in yellow lupine is associated with the varied expression of α and β subunits into the complexes of hexameric GDH forms. The presence of several isogenes of GDH in yellow lupine may explain the high number (over 20) of its molecular forms in germinating lupine.

  11. Aldehyde Dehydrogenase Gene Superfamily in Populus: Organization and Expression Divergence between Paralogous Gene Pairs.

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    Feng-Xia Tian

    Full Text Available Aldehyde dehydrogenases (ALDHs constitute a superfamily of NAD(P+-dependent enzymes that catalyze the irreversible oxidation of a wide range of reactive aldehydes to their corresponding nontoxic carboxylic acids. ALDHs have been studied in many organisms from bacteria to mammals; however, no systematic analyses incorporating genome organization, gene structure, expression profiles, and cis-acting elements have been conducted in the model tree species Populus trichocarpa thus far. In this study, a comprehensive analysis of the Populus ALDH gene superfamily was performed. A total of 26 Populus ALDH genes were found to be distributed across 12 chromosomes. Genomic organization analysis indicated that purifying selection may have played a pivotal role in the retention and maintenance of PtALDH gene families. The exon-intron organizations of PtALDHs were highly conserved within the same family, suggesting that the members of the same family also may have conserved functionalities. Microarray data and qRT-PCR analysis indicated that most PtALDHs had distinct tissue-specific expression patterns. The specificity of cis-acting elements in the promoter regions of the PtALDHs and the divergence of expression patterns between nine paralogous PtALDH gene pairs suggested that gene duplications may have freed the duplicate genes from the functional constraints. The expression levels of some ALDHs were up- or down-regulated by various abiotic stresses, implying that the products of these genes may be involved in the adaptation of Populus to abiotic stresses. Overall, the data obtained from our investigation contribute to a better understanding of the complexity of the Populus ALDH gene superfamily and provide insights into the function and evolution of ALDH gene families in vascular plants.

  12. The cinnamyl alcohol dehydrogenase gene family in melon (Cucumis melo L.): bioinformatic analysis and expression patterns.

    Science.gov (United States)

    Jin, Yazhong; Zhang, Chong; Liu, Wei; Qi, Hongyan; Chen, Hao; Cao, Songxiao

    2014-01-01

    Cinnamyl alcohol dehydrogenase (CAD) is a key enzyme in lignin biosynthesis. However, little was known about CADs in melon. Five CAD-like genes were identified in the genome of melons, namely CmCAD1 to CmCAD5. The signal peptides analysis and CAD proteins prediction showed no typical signal peptides were found in all CmCADs and CmCAD proteins may locate in the cytoplasm. Multiple alignments implied that some motifs may be responsible for the high specificity of these CAD proteins, and may be one of the key residues in the catalytic mechanism. The phylogenetic tree revealed seven groups of CAD and melon CAD genes fell into four main groups. CmCAD1 and CmCAD2 belonged to the bona fide CAD group, in which these CAD genes, as representative from angiosperms, were involved in lignin synthesis. Other CmCADs were distributed in group II, V and VII, respectively. Semi-quantitative PCR and real time qPCR revealed differential expression of CmCADs, and CmCAD5 was expressed in different vegetative tissues except mature leaves, with the highest expression in flower, while CmCAD2 and CmCAD5 were strongly expressed in flesh during development. Promoter analysis revealed several motifs of CAD genes involved in the gene expression modulated by various hormones. Treatment of abscisic acid (ABA) elevated the expression of CmCADs in flesh, whereas the transcript levels of CmCAD1 and CmCAD5 were induced by auxin (IAA); Ethylene induced the expression of CmCADs, while 1-MCP repressed the effect, apart from CmCAD4. Taken together, these data suggested that CmCAD4 may be a pseudogene and that all other CmCADs may be involved in the lignin biosynthesis induced by both abiotic and biotic stresses and in tissue-specific developmental lignification through a CAD genes family network, and CmCAD2 may be the main CAD enzymes for lignification of melon flesh and CmCAD5 may also function in flower development.

  13. Human GLUD2 glutamate dehydrogenase is expressed in neural and testicular supporting cells.

    Science.gov (United States)

    Spanaki, Cleanthe; Zaganas, Ioannis; Kleopa, Kleopas A; Plaitakis, Andreas

    2010-05-28

    Mammalian glutamate dehydrogenase (GDH) is an allosterically regulated enzyme that is expressed widely. Its activity is potently inhibited by GTP and thought to be controlled by the need of the cell for ATP. In addition to this housekeeping human (h) GDH1, humans have acquired (via a duplication event) a highly homologous isoenzyme (hGDH2) that is resistant to GTP. Although transcripts of GLUD2, the gene encoding hGDH2, have been detected in human neural and testicular tissues, data on the endogenous protein are lacking. Here, we developed an antibody specific for hGDH2 and used it to study human tissues. Western blot analyses revealed, to our surprise, that endogenous hGDH2 is more densely expressed in testis than in brain. At the subcellular level, hGDH2 localized to mitochondria. Study of testicular tissue using immunocytochemical and immunofluorescence methods revealed that the Sertoli cells were strongly labeled by our anti-hGDH2 antibody. In human cerebral cortex, a robust labeling of astrocytes was detected, with neurons showing faint hGDH2 immunoreactivity. Astrocytes and Sertoli cells are known to support neurons and germ cells, respectively, providing them with lactate that largely derives from the tricarboxylic acid cycle via conversion of glutamate to alpha-ketoglutarate (GDH reaction). As hGDH2 is not subject to GTP control, the enzyme is able to metabolize glutamate even when the tricarboxylic acid cycle generates GTP amounts sufficient to inactivate the housekeeping hGDH1 protein. Hence, the selective expression of hGDH2 by astrocytes and Sertoli cells may provide a significant biological advantage by facilitating metabolic recycling processes essential to the supportive role of these cells.

  14. Gene clone,expression and enzyme activity assay of a cytosolic malate dehydrogenase from apple fruits

    Institute of Scientific and Technical Information of China (English)

    Yuxin YAO; Yujin HAO; Ming LI; Mingli PANG; Zhi LIU; Heng ZHAI

    2008-01-01

    Malate dehydrogenase (MDH) ubiquitously exists in animals,plants and microoganisms,and catalyzes the interconversion from oxaloacetate to malate.Cytosolic NAD-dependent MDH gene (cyMDH)encodes a key enzyme crucial for malic acid synthesis in the cytosol which has not been extensively characterized in plants.In this study,a full-length cDNA of cyMDH was isolated from apple fruits with RT-PCR as well as 3' and 5' rapid amplification of cDNA ends,and designated as Mal-cyMDH (GenBank accession No.DQ221207).It contained a 996-bp ORF and its sequence analysis shows a high similarity to other plant cyMDHs.Phylogenetic analysis indicated that almost all the cyMDHs could be clustered into the same group and it was likely to represent the original MDH.A roughly 37-kDa fused protein was obtained by the recombinant prokaryotic expression and its enzyme activity assay showed that it mainly catalyzed oxaloacetate to malate.It was also discovered that the enzyme activity of cyMDH exhibited remarkable difference between the high- and low-acid apple germplasm.

  15. Expression and identification of a thermostable malate dehydrogenase from multicellular prokaryote Streptomyces avermitilis MA-4680.

    Science.gov (United States)

    Wang, Zong-Da; Wang, Bao-Juan; Ge, Ya-Dong; Pan, Wei; Wang, Jie; Xu, Lei; Liu, Ai-Min; Zhu, Guo-Ping

    2011-03-01

    A malate dehydrogenase (MDH) from Streptomyces avermitilis MA-4680 (SaMDH) has been expressed and purified as a fusion protein. The molecular mass of SaMDH is about 35 kDa determined by SDS-PAGE. The recombinant SaMDH has a maximum activity at pH 8.0. The enzyme shows the optimal temperature around 42 °C and displays a half-life (t(1/2)) of 160 min at 50°C which is more thermostable than reported MDHs from most bacteria and fungi. The k(cat) value of SaMDH is about 240-fold of that for malate oxidation. In addition, the k(cat)/K(m) ratio shows that SaMDH has about 1,246-fold preference for oxaloacetate (OAA) reduction over L-malate oxidation. The recombinant SaMDH may also use NADPH as a cofactor although it is a highly NAD(H)-specific enzyme. There was no activity detected when malate and NADP(+) were used as substrates. Substrate inhibition studies show that SaMDH activity is strongly inhibited by excess OAA with NADH, but is not sensitive to excess L-malate. Enzymatic activity is enhanced by the addition of Na(+), NH(4)(+), Ca(2+), Cu(2+) and Mg(2+) and inhibited by addition of Hg(2+) and Zn(2+). MDH is widely used in coenzyme regeneration, antigen immunoassays and bioreactors. The enzymatic analysis could provide the important basic knowledge for its utilizations.

  16. Selective n-butanol production by Clostridium sp. MTButOH1365 during continuous synthesis gas fermentation due to expression of synthetic thiolase, 3-hydroxy butyryl-CoA dehydrogenase, crotonase, butyryl-CoA dehydrogenase, butyraldehyde dehydrogenase, and NAD-dependent butanol dehydrogenase.

    Science.gov (United States)

    Berzin, Vel; Tyurin, Michael; Kiriukhin, Michael

    2013-02-01

    Acetogen Clostridum sp. MT1962 produced 287 mM acetate (p < 0.005) and 293 mM ethanol (p < 0.005) fermenting synthesis gas blend 60% CO and 40% H₂ in single-stage continuous fermentation. This strain was metabolically engineered to the biocatalyst Clostridium sp. MTButOH1365. The engineered biocatalyst lost production of ethanol and acetate while initiated the production of 297 mM of n-butanol (p < 0.005). The metabolic engineering comprised Cre-lox66/lox71-based elimination of phosphotransacetylase and acetaldehyde dehydrogenase along with integration to chromosome synthetic thiolase, 3-hydroxy butyryl-CoA dehydrogenase, crotonase, butyryl-CoA dehydrogenase, butyraldehyde dehydrogenase, and NAD-dependent butanol dehydrogenase. This is the first report on elimination of acetate and ethanol production genes and expression of synthetic gene cluster encoding n-butanol biosynthesis pathway in acetogen biocatalyst for selective fuel n-butanol production with no antibiotic support for the introduced genes.

  17. Diversity in expression of glucose-6-phosphate dehydrogenase deficiency in females.

    Science.gov (United States)

    Abdulrazzaq, Y M; Micallef, R; Qureshi, M; Dawodu, A; Ahmed, I; Khidr, A; Bastaki, S M; Al-Khayat, A; Bayoumi, R A

    1999-01-01

    The aims of this study were to determine the prevalence of glucose-6-phosphate dehydrogenase (G6PD) deficiency in the United Arab Emirates (UAE), to describe the different mutations in the population, to determine its prevalence, and to study inheritance patterns in families of G6PD-deficient individuals. All infants born at Tawam Hospital, Al-Ain, UAE from January 1994 to September 1996 were screened at birth for their G6PD status. In addition, those attending well-baby clinics during the period were also screened for the disorder. Families of 40 known G6PD-deficient individuals, selected randomly from the records of three hospitals in the country, were assessed for G6PD deficiency. Where appropriate, this was followed by definition of G6PD mutations. Of 8198 infants, 746 (9.1%), comprising 15% of males and 5% of females tested, were found to be G6PD deficient. A total of 27 families were further assessed: of these, all but one family had the nt563 Mediterranean mutation. In one family, two individuals had the nt202 African mutation. The high manifestation of G6PD deficiency in women may be due to the preferential expression of the G6PD-deficient gene and X-inactivation of the normal gene, and/or to the presence of an 'enhancer' gene that makes the expression of the G6PD deficiency more likely. The high level of consanguinity which, theoretically, should result in a high proportion of homozygotes and consequently a higher proportion of females with the deficiency, was not found to be a significant factor.

  18. Expression, characterization and mutagenesis of an FAD-dependent glucose dehydrogenase from Aspergillus terreus.

    Science.gov (United States)

    Yang, Yufeng; Huang, Lei; Wang, Jufang; Xu, Zhinan

    2015-01-01

    An FAD-dependent glucose dehydrogenase (FAD-GDH) from Aspergillus terreus NIH2624 was expressed in Escherichia coli with a yield of 228±16U/L of culture. Co-expression with chaperones DnaK/DnaJ/GrpE and osmotic stress induced by simple carbon sources enhanced productivity significantly, improving the yield to 23883±563U/L after optimization. FAD-GDH was purified in two steps with the specific activity of 604U/mg. Using d-glucose as substrate, the optimal pH and temperature for FAD-GDH were determined to be 7.5 and 50°C, respectively. Activity was stable across the pH range 3.5-9.0, and the half-life was 52min at 42°C. Km and Vmax were calculated as 86.7±5.3mM and 928±35U/mg, and the molecular weight was approximately 65.6kDa based on size exclusion chromatography, indicating a monomeric structure. The 3D structure of FAD-GDH was simulated by homology modelling using the structure of A. niger glucose oxidase (GOD) as template. From the model, His551, His508, Asn506 and Arg504 were identified as key residues, and their importance was verified by site-directed mutagenesis. Furthermore, three additional mutants (Arg84Ala, Tyr340Phe and Tyr406Phe) were generated and all exhibited a higher degree of substrate specificity than the native enzyme. These results extend our understanding of the structure and function of FAD-GDH, and could assist potential commercial applications.

  19. Molecular cloning, co-expression, and characterization of glycerol dehydratase and 1,3-propanediol dehydrogenase from Citrobacter freundii.

    Science.gov (United States)

    Qi, Xianghui; Deng, Wenying; Wang, Fei; Guo, Qi; Chen, Huayou; Wang, Liang; He, Xiang; Huang, Ribo

    2013-06-01

    1,3-Propanediol (1,3-PD), an important material for chemical industry, is biologically synthesized by glycerol dehydratase (GDHt) and 1,3-propanediol dehydrogenase (PDOR). In present study, the dhaBCE and dhaT genes encoding glycerol dehydratase and 1,3-propanediol dehydrogenase respectively were cloned from Citrobacter freundii and co-expressed in E. coli. Sequence analysis revealed that the cloned genes were 85 and 77 % identical to corresponding gene of C. freundii DSM 30040 (GenBank No. U09771), respectively. The over-expressed recombinant enzymes were purified by nickel-chelate chromatography combined with gel filtration, and recombinant GDHt and PDOR were characterized by activity assay, kinetic analysis, pH, and temperature optimization. This research may form a basis for the future work on biological synthesis of 1,3-PD.

  20. Expression of NAD+-dependent formate dehydrogenase in Enterobacter aerogenes and its involvement in anaerobic metabolism and H2 production.

    Science.gov (United States)

    Lu, Yuan; Zhao, Hongxin; Zhang, Chong; Lai, Qiheng; Wu, Xi; Xing, Xin-Hui

    2009-10-01

    An expression system for NAD(+)-dependent formate dehydrogenase gene (fdh1), from Candida boidinii, was constructed and cloned into Enterobacter aerogenes IAM1183. With the fdh1 expression, the total H(2) yield was attributed to a decrease in activity of the lactate pathway and an increase of the formate pathway flux due to the NADH regeneration. Analysis of the redox state balance and ethanol-to-acetate ratio in the fdhl-expressed strain showed that increased reducing power arose from the reconstruction of NADH regeneration pathway from formate thereby contributing to the improved H(2) production.

  1. Relationship between the Expression of Thymidylate Synthase,Thymidine Phosphorylase and Dihydropyrimidine Dehydrogenase and Survival in Epithelial Ovarian Cancer

    Institute of Scientific and Technical Information of China (English)

    王常玉; 翁艳洁; 王鸿雁; 石英; 马丁

    2010-01-01

    The mRNA and protein expression of thymidylate synthase (TS), thymidine phosphorylase (TP) and dihydropyrimidine dehydrogenase (DPD) and their relationship with prognosis were investigated. Real-time quantitative RT-PCR (Taqman) was used to detect the mRNA expression of TS, TP and DPD in formalin-fixed and paraffin-embedded 106 samples of epithelial ovarian cancer and 29 normal ovaries. A TATA box-binding protein (TBP) was used as an endogenous reference gene. A relationship between TS, TP, DPD expression a...

  2. Dihydropyrimidine dehydrogenase (DPD) expression is negatively regulated by certain microRNAs in human lung tissues.

    Science.gov (United States)

    Hirota, Takeshi; Date, Yuko; Nishibatake, Yu; Takane, Hiroshi; Fukuoka, Yasushi; Taniguchi, Yuuji; Burioka, Naoto; Shimizu, Eiji; Nakamura, Hiroshige; Otsubo, Kenji; Ieiri, Ichiro

    2012-07-01

    Dihydropyrimidine dehydrogenase (DPD) is important to the antitumor effect of 5-fluorouracil (5-FU). DPD gene (DPYD) expression in tumors is correlated with sensitivity to 5-FU. Because the 5-FU accumulated in cancer cells is also rapidly converted into inactivated metabolites through catabolic pathways mediated by DPD, high DPD activity in cancer cells is an important determinant of the response to 5-FU. DPD activity is highly variable and reduced activity causes a high risk of 5-FU toxicity. Genetic variation in DPYD has been proposed as the main factor responsible for the variation in DPD activity. However, only a small proportion of the activity of DPD can be explained by DPYD mutations. In this study, we found that DPYD is a target of the following microRNAs (miRNA): miR-27a, miR-27b, miR-134, and miR-582-5p. In luciferase assays with HepG2 cells, the overexpression of these miRNAs was associated with significantly decreased reporter activity in a plasmid containing the 3'-UTR of DYPD mRNA. The level of DPD protein in MIAPaca-2 cells was also significantly decreased by the overexpression of these four miRNAs. The results suggest that miR-27a, miR-27b, miR-134, and miR-582-5p post-transcriptionally regulate DPD protein expression. The levels of miRNAs in normal lung tissue and lung tumors were compared; miR-27b and miR-134 levels were significantly lower in the tumors than normal tissue (3.64 ± 4.02 versus 9.75 ± 6.58 and 0.64 ± 0.75 versus 1.48 ± 1.39). DPD protein levels were significantly higher in the tumors. Thus, the decreased expression of miR-27b would be responsible for the high levels of DPD protein. This study is the first to show that miRNAs regulate the DPD protein, and provides new insight into 5-FU-based chemotherapy.

  3. Expression of novel cytosolic malate dehydrogenases (cMDH) in Lupinus angustifolius nodules during phosphorus starvation.

    Science.gov (United States)

    Le Roux, Marcellous; Phiri, Ethel; Khan, Wesaal; Sakiroğlu, Muhammet; Valentine, Alex; Khan, Sehaam

    2014-11-01

    During P deficiency, the increased activity of malate dehydrogenase (MDH, EC 1.1.1.37) can lead to malate accumulation. Cytosolic- and nodule-enhanced MDH (cMDH and neMDH, respectively) are known isoforms, which contribute to MDH activity in root nodules. The aim of this study was to investigate the role of the cMDH isoforms in nodule malate supply under P deficiency. Nodulated lupins (Lupinus angustifolius var. Tanjil) were hydroponically grown at adequate P (+P) or low P (-P). Total P concentration in nodules decreased under P deficiency, which coincided with an increase in total MDH activity. A consequence of higher MDH activity was the enhanced accumulation of malate derived from dark CO2 fixation via PEPC and not from pyruvate. Although no measurable neMDH presence could be detected via PCR, gene-specific primers detected two 1kb amplicons of cMDH, designated LangMDH1 (corresponding to +P, HQ690186) and LangMDH2 (corresponding to -P, HQ690187), respectively. Sequencing analyses of these cMDH amplicons showed them to be 96% identical on an amino acid level. There was a high degree of diversification between proteins detected in this study and other known MDH proteins, particularly those from other leguminous plants. Enhanced malate synthesis in P-deficient nodules was achieved via increased anaplerotic CO2 fixation and subsequent higher MDH activities. Novel isoforms of cytosolic MDH may be involved, as shown by gene expression of specific genes under P deficiency.

  4. Functional expression of a fragment of human dihydroorotate dehydrogenase by means of the baculovirus expression vector system, and kinetic investigation of the purified recombinant enzyme.

    Science.gov (United States)

    Knecht, W; Bergjohann, U; Gonski, S; Kirschbaum, B; Löffler, M

    1996-08-15

    Human mitochondrial dihydroorotate dehydrogenase (the fourth enzyme of pyrimidine de novo synthesis) has been overproduced by means of a recombinant baculovirus that contained the human cDNA fragment for this protein. After virus infection and protein expression in Trichoplusia ni cells (BTI-Tn-5B1-4), the subcellular distribution of the recombinant dihydroorotate dehydrogenase was determined by two distinct enzyme-activity assays and by Western blot analysis with anti-(dihydroorotate dehydrogenase) Ig. The targeting of the recombinant protein to the mitochondria of the insect cells was verified. The activity of the recombinant enzyme in the mitochondria of infected cells was about 740-fold above the level of dihydroorotate dehydrogenase in human liver mitochondria. In a three-step procedure, dihydroorotate dehydrogenase was purified to a specific activity of greater than 50 U/mg. Size-exclusion chromatography showed a molecular mass of 42 kDa and confirmed the existence of the fully active enzyme as a monomeric species. Fluorimetric cofactor analysis revealed the presence of FMN in recombinant dihydroorotate dehydrogenase. By kinetics analysis, Km values for dihydroorotate and ubiquinone-50 were found to be 4 microM and 9.9 microM, respectively, while Km values for dihydroorotate and decylubiquinone were 9.4 microM and 13.7 microM, respectively. The applied expression system will allow preparation of large quantities of the enzyme for structure and function studies. Purified recombinant human dihytdroorotate dehydrogenase was tested for its sensitivity to a reported inhibitor A77 1726 (2-hydroxyethyliden-cyanoacetic acid 4-trifluoromethyl anilide), which is the active metabolite of the isoxazole derivative leflunomide [5-methyl-N-(4-trifluoromethyl-phenyl)-4-isoxazole carboximide]. An IC50 value of 1 microM was determined for A77 1726. Detailed kinetics experiments revealed uncompetitive inhibition with respect to dihydroorotate (Kiu = 0.94 microM) and non

  5. Highly selective anti-Prelog synthesis of optically active aryl alcohols by recombinant Escherichia coli expressing stereospecific alcohol dehydrogenase.

    Science.gov (United States)

    Li, Ming; Nie, Yao; Mu, Xiao Qing; Zhang, Rongzhen; Xu, Yan

    2016-07-03

    Biocatalytic asymmetric synthesis has been widely used for preparation of optically active chiral alcohols as the important intermediates and precursors of active pharmaceutical ingredients. However, the available whole-cell system involving anti-Prelog specific alcohol dehydrogenase is yet limited. A recombinant Escherichia coli system expressing anti-Prelog stereospecific alcohol dehydrogenase from Candida parapsilosis was established as a whole-cell system for catalyzing asymmetric reduction of aryl ketones to anti-Prelog configured alcohols. Using 2-hydroxyacetophenone as the substrate, reaction factors including pH, cell status, and substrate concentration had obvious impacts on the outcome of whole-cell biocatalysis, and xylose was found to be an available auxiliary substrate for intracellular cofactor regeneration, by which (S)-1-phenyl-1,2-ethanediol was achieved with an optical purity of 97%e.e. and yield of 89% under the substrate concentration of 5 g/L. Additionally, the feasibility of the recombinant cells toward different aryl ketones was investigated, and most of the corresponding chiral alcohol products were obtained with an optical purity over 95%e.e. Therefore, the whole-cell system involving recombinant stereospecific alcohol dehydrogenase was constructed as an efficient biocatalyst for highly enantioselective anti-Prelog synthesis of optically active aryl alcohols and would be promising in the pharmaceutical industry.

  6. The E1 beta-subunit of pyruvate dehydrogenase is surface-expressed in Lactobacillus plantarum and binds fibronectin.

    Science.gov (United States)

    Vastano, Valeria; Salzillo, Marzia; Siciliano, Rosa A; Muscariello, Lidia; Sacco, Margherita; Marasco, Rosangela

    2014-01-01

    Lactobacillus plantarum is among the species with a probiotic activity. Adhesion of probiotic bacteria to host tissues is an important principle for strain selection, because it represents a crucial step in the colonization process of either pathogens or commensals. Most bacterial adhesins are proteins, and a major target for them is fibronectin, an extracellular matrix glycoprotein. In this study we demonstrate that PDHB, a component of the pyruvate dehydrogenase complex, is a factor contributing to fibronectin-binding in L. plantarum LM3. By means of fibronectin overlay immunoblotting assay, we identified a L. plantarum LM3 surface protein with apparent molecular mass of 35 kDa. Mass spectrometric analysis shows that this protein is the pyruvate dehydrogenase E1 beta-subunit (PDHB). The corresponding pdhB gene is located in a 4-gene cluster encoding pyruvate dehydrogenase. In LM3-B1, carrying a null mutation in pdhB, the 35 kDa adhesin was not anymore detectable by immunoblotting assay. Nevertheless, the pdhB null mutation did not abolish pdhA, pdhC, and pdhD transcription in LM3-B1. By adhesion assays, we show that LM3-B1 cells bind to immobilized fibronectin less efficiently than wild type cells. Moreover, we show that pdhB expression is negatively regulated by the CcpA protein and is induced by bile.

  7. Characterization of the highly active fragment of glyceraldehyde-3-phosphate dehydrogenase gene promoter for recombinant protein expression in Pleurotus ostreatus.

    Science.gov (United States)

    Yin, Chaomin; Zheng, Liesheng; Zhu, Jihong; Chen, Liguo; Ma, Aimin

    2015-03-01

    Developing efficient native promoters is important for improving recombinant protein expression by fungal genetic engineering. The promoter region of glyceraldehyde-3-phosphate dehydrogenase gene in Pleurotus ostreatus (Pogpd) was isolated and optimized by upstream truncation. The activities of these promoters with different lengths were further confirmed by fluorescence, quantitative real-time PCR and Western blot analysis. A truncated Pogpd-P2 fragment (795 bp) drove enhanced green fluorescence protein (egfp) gene expression in P. ostreatus much more efficiently than full-length Pogpd-P1. Further truncating Pogpd-P2 to 603, 403 and 231 bp reduced the eGFP expression significantly. However, the 403-bp fragment between -356 bp and the start codon was the minimal but sufficient promoter element for eGFP expression. Compact native promoters for genetic engineering of P. ostreatus were successfully developed and validated in this study. This will broaden the preexisting repertoire of fungal promoters for biotechnology application.

  8. Cloning, sequencing and functional expression of cytosolic malate dehydrogenase from Taenia solium: Purification and characterization of the recombinant enzyme.

    Science.gov (United States)

    Nava, Gabriela; Laclette, Juan P; Bobes, Raúl; Carrero, Julio C; Reyes-Vivas, Horacio; Enriquez-Flores, Sergio; Mendoza-Hernández, Guillermo; Plancarte, Agustín

    2011-07-01

    We report herein the complete coding sequence of a Taenia solium cytosolic malate dehydrogenase (TscMDH). The cDNA fragment, identified from the T. solium genome project database, encodes a protein of 332 amino acid residues with an estimated molecular weight of 36517Da. For recombinant expression, the full length coding sequence was cloned into pET23a. After successful expression and enzyme purification, isoelectrofocusing gel electrophoresis allowed to confirm the calculated pI value at 8.1, as deduced from the amino acid sequence. The recombinant protein (r-TscMDH) showed MDH activity of 409U/mg in the reduction of oxaloacetate, with neither lactate dehydrogenase activity nor NADPH selectivity. Optimum pH for enzyme activity was 7.6 for oxaloacetate reduction and 9.6 for malate oxidation. K(cat) values for oxaloacetate, malate, NAD, and NADH were 665, 47, 385, and 962s(-1), respectively. Additionally, a partial characterization of TsMDH gene structure after analysis of a 1.56Kb genomic contig assembly is also reported.

  9. Transcription analysis of pyranose dehydrogenase from the basidiomycete Agaricus bisporus and characterization of the recombinantly expressed enzyme.

    Science.gov (United States)

    Gonaus, Christoph; Kittl, Roman; Sygmund, Christoph; Haltrich, Dietmar; Peterbauer, Clemens

    2016-03-01

    Agaricus bisporus is a litter degrading basidiomycete commonly found in humic-rich environments. It is used as model organism and cultivated in large scale for food industry. Due to its ecological niche it produces a variety of enzymes for detoxification and degradation of humified plant litter. One of these, pyranose dehydrogenase, is thought to play a role in detoxification and lignocellulose degradation. It is a member of the glucose-methanol-choline family of flavin-dependent enzymes and oxidizes a wide range of sugars with concomitant reduction of electron acceptors like quinones. In this work, transcription of pdh in A. bisporus was investigated with real-time PCR revealing influence of the carbon source on pdh expression levels. The gene was isolated and heterologously expressed in Pichia pastoris. Characterization of the recombinant enzyme showed a higher affinity towards disaccharides compared to other tested pyranose dehydrogenases from related Agariceae. Homology modeling and sequence alignments indicated that two loops of high sequence variability at substrate access site could play an important role in modulating these substrate specificities.

  10. Age-related changes in the expression of 11beta-hydroxysteroid dehydrogenase type 2 in rat Leydig cells.

    Directory of Open Access Journals (Sweden)

    Katerina Georgieva

    2009-12-01

    Full Text Available Previous studies in rats have shown that the ability of Leydig cells (LCs to produce testosterone significantly declines with age. To address the possible mechanisms by which aging LCs lose their steroidogenic function, we determined the effect of aging on the expression of 11beta-hydroxysteroid dehydrogenase (11beta-HSD type 2. The enzyme plays a protective role in blunting the suppressive effects of glucocorticoids on LCs steroidogenesis. Our immunohistochemical analysis revealed progressive decline in 11beta-HDS type 2 expression in LCs of the 18 months of age rats and the most significant reduction in 11beta-HSD2 immunoreactivity was evident in the testicular interstitium of 24- month-old rats. The decrease in the 11beta-HDS type 2 immunostaining in LCs during aging coincided with decline in insulin-like 3/relaxin-like factor (INSL3/RLF expression, an independent marker for LCs differentiation status. Concomitant with the age-related decrease of 11beta-HDS type 2 immunoreactivity in the LCs population, the immunoexpression of 3beta-hydroxysteroid dehydrogenase (3beta-HSD, marker for LCs steroidogenic activity, was greatly reduced at 24 months compared to 3-month-old control. Similar pattern of expression exhibited also androgen receptor (AR which is localized in the nuclei of Sertoli cells (SCs, LCs, and peritubular cells. During ages we observed progressive decrease in the immunoreactivity for AR in the testicular types and there was a loss of stage specificity in SCs at age of 24 months. It now seems evident that a variety of factors are likely to be involved in age-related decreases in LCs steroidogenesis, including 11beta-HSD type 2. The observed reduction in 11beta-HSD type 2 expression in aging LCs reflects the decline in their protection ability, opposing the suppressive effect of glucocorticoids on testosterone production.

  11. Teneligliptin Decreases Uric Acid Levels by Reducing Xanthine Dehydrogenase Expression in White Adipose Tissue of Male Wistar Rats

    Directory of Open Access Journals (Sweden)

    Chihiro Moriya

    2016-01-01

    Full Text Available We investigated the effects of teneligliptin on uric acid metabolism in male Wistar rats and 3T3-L1 adipocytes. The rats were fed with a normal chow diet (NCD or a 60% high-fat diet (HFD with or without teneligliptin for 4 weeks. The plasma uric acid level was not significantly different between the control and teneligliptin groups under the NCD condition. However, the plasma uric acid level was significantly decreased in the HFD-fed teneligliptin treated rats compared to the HFD-fed control rats. The expression levels of xanthine dehydrogenase (Xdh mRNA in liver and epididymal adipose tissue of NCD-fed rats were not altered by teneligliptin treatment. On the other hand, Xdh expression was reduced significantly in the epididymal adipose tissue of the HFD-fed teneligliptin treated rats compared with that of HFD-fed control rats, whereas Xdh expression in liver did not change significantly in either group. Furthermore, teneligliptin significantly decreased Xdh expression in 3T3-L1 adipocytes. DPP-4 treatment significantly increased Xdh expression in 3T3-L1 adipocytes. With DPP-4 pretreatment, teneligliptin significantly decreased Xdh mRNA expression compared to the DPP-4-treated 3T3-L1 adipocytes. In conclusion, our studies suggest that teneligliptin reduces uric acid levels by suppressing Xdh expression in epididymal adipose tissue of obese subjects.

  12. Reduced expression of 15-hydroxy prostaglandin dehydrogenase in chorion during labor is associated with decreased PRB and increased PRA and GR expression.

    Science.gov (United States)

    Li, Yuan; He, Ping; Sun, Qianqian; Liu, Jie; Gao, Lu; You, Xingji; Gu, Hang; Ni, Xin

    2013-05-01

    The chorion laeve controls the levels of active prostaglandins within the uterus by NAD-dependent 15-hydroxy prostaglandin dehydrogenase (PGDH). The expression of PGDH in chorion is modulated by glucocorticoids and progesterone. In this study, we investigated glucocorticoid receptor (GR) and progesterone receptor A and B (PRA and PRB) in the regulation of PGDH expression in chorion, and we determined whether reduced PGDH expression in chorion during labor is associated with the changes in GR and PR expression by real-time RT-PCR and Western blot analysis. Dexamethasone (DEX) inhibited PGDH expression whereas progesterone stimulated PGDH expression in chorionic trophoblasts. DEX suppressed PGDH expression in GR overexpression and PR knockdown cells. The inhibitory effect of DEX did not occur in GR knockdown cells. Progesterone inhibited PGDH in GR overexpression and PR knockdown cells and it stimulated PGDH in PRB overexpression cells whereas it suppressed PGDH in PRA overexpression cells. Knockdown of c-Jun resulted in a loss of progesterone- and DEX-induced effects. PGDH was down-regulated in chorion tissues during labor. PRB was decreased whereas PRA and GR were increased in chorion during labor. Glucocorticoids inhibit PGDH expression via GR in chorionic trophoblasts. Progesterone enhances PGDH expression through PRB, whereas it inhibits PGDH expression via GR and PRA. Decreased PGDH expression is associated with increased GR and PRA, although decreased PRB, in chorion during labor.

  13. Taraxerone enhances alcohol oxidation via increases of alcohol dehyderogenase (ADH) and acetaldehyde dehydrogenase (ALDH) activities and gene expressions.

    Science.gov (United States)

    Sung, Chang-Keun; Kim, Seung-Mi; Oh, Chang-Jin; Yang, Sun-A; Han, Byung-Hee; Mo, Eun-Kyoung

    2012-07-01

    The present study, taraxerone (d-friedoolean-14-en-3-one) was isolated from Sedum sarmentosum with purity 96.383%, and its enhancing effects on alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) activities were determined: EC(50) values were 512.42 ± 3.12 and 500.16 ± 3.23 μM for ADH and ALDH, respectively. In order to obtain more information on taraxerone related with the alcohol metabolism, 40% ethanol (5 mL/kg body weight) with 0.5-1mM of taraxerone were administered to mice. The plasma alcohol and acetaldehyde concentrations of taraxerone-treated groups were significantly lowered than those of the control group (p<0.01): approximately 20-67% and 7-57% lowered for plasma alcohol and acetaldehyde, respectively. Compare to the control group, the ADH and ALDH expressions in the liver tissues were abruptly increased in the taraxerone-treated groups after ethanol exposure. In addition, taraxerone prevented catalase, superoxide dismutase, and reduced glutathione concentrations from the decrease induced by ethanol administration with the concentration dependent manner.

  14. Cloning and heterologous expression of two aryl-aldehyde dehydrogenases from the white-rot basidiomycete Phanerochaete chrysosporium

    Energy Technology Data Exchange (ETDEWEB)

    Nakamura, Tomofumi [Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Fukuoka Institute of Health and Environmental Sciences, 39 Mukaizano, Dazaifu-shi, Fukuoka 818-0135 (Japan); Ichinose, Hirofumi [Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Wariishi, Hiroyuki, E-mail: hirowari@agr.kyushu-u.ac.jp [Faculty of Agriculture, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Bio-Architecture Center, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan); Innovation Center for Medical Redox Navigation, Kyushu University, 6-10-1 Hakozaki, Higashi-ku, Fukuoka 812-8581 (Japan)

    2010-04-09

    We identified two aryl-aldehyde dehydrogenase proteins (PcALDH1 and PcALDH2) from the white-rot basidiomycete Phanerochaete chrysosporium. Both PcALDHs were translationally up-regulated in response to exogenous addition of vanillin, one of the key aromatic compounds in the pathway of lignin degradation by basidiomycetes. To clarify the catalytic functions of PcALDHs, we isolated full-length cDNAs encoding these proteins and heterologously expressed the recombinant enzymes using a pET/Escherichia coli system. The open reading frames of both PcALDH1 and PcALDH2 consisted of 1503 nucleotides. The deduced amino acid sequences of both proteins showed high homologies with aryl-aldehyde dehydrogenases from other organisms and contained ten conserved domains of ALDHs. Moreover, a novel glycine-rich motif 'GxGxxxG' was located at the NAD{sup +}-binding site. The recombinant PcALDHs catalyzed dehydrogenation reactions of several aryl-aldehyde compounds, including vanillin, to their corresponding aromatic acids. These results strongly suggested that PcALDHs metabolize aryl-aldehyde compounds generated during fungal degradation of lignin and various aromatic xenobiotics.

  15. Abscisic acid effects on activity and expression of barley (Hordeum vulgare) plastidial glucose-6-phosphate dehydrogenase.

    Science.gov (United States)

    Cardi, Manuela; Chibani, Kamel; Cafasso, Donata; Rouhier, Nicolas; Jacquot, Jean-Pierre; Esposito, Sergio

    2011-07-01

    Total glucose-6-phosphate dehydrogenase (G6PDH) activity, protein abundance, and transcript levels of G6PDH isoforms were measured in response to exogenous abscisic acid (ABA) supply to barley (Hordeum vulgare cv Nure) hydroponic culture. Total G6PDH activity increased by 50% in roots treated for 12 h with exogenous 0.1 mM ABA. In roots, a considerable increase (35%) in plastidial P2-G6PDH transcript levels was observed during the first 3 h of ABA treatment. Similar protein variations were observed in immunoblotting analyses. In leaves, a 2-fold increase in total G6PDH activity was observed after ABA treatment, probably related to an increase in the mRNA level (increased by 50%) and amount of protein (increased by 85%) of P2-G6PDH. Together these results suggest that the plastidial P2-isoform plays an important role in ABA-treated barley plants.

  16. Isoform expression in the multiple soluble malate dehydrogenase of Hoplias malabaricus (Erythrinidae, Characiformes

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    M. R. Aquino-Silva

    Full Text Available Kinetic properties and thermal stabilities of Hoplias malabaricus liver and skeletal muscle unfractionated malate dehydrogenase (MDH, EC 1.1.1.37 and its isolated isoforms were analyzed to further study the possible sMDH-A* locus duplication evolved from a recent tandem duplication. Both A (A1 and A2 and B isoforms had similar optima pH (7.5-8.0. While Hoplias A isoform could not be characterized as thermostable, B could as thermolabile. A isoforms differed from B isoform in having higher Km values for oxaloacetate. The possibly duplicated A2 isoform showed higher substrate affinity than the A1. Hoplias duplicated A isoforms may influence the direction of carbon flow between glycolisis and gluconeogenesis.

  17. Expression, purification, crystallization and preliminary X-ray analysis of an NADP-dependent glyceraldehyde-3-phosphate dehydrogenase from Helicobacter pylori

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, Paul R.; Evans, Daniel; Greenwood, Jacqueline A.; Moody, Peter C. E., E-mail: pcem1@leicester.ac.uk [Henry Wellcome Laboratories for Structural Biology, Department of Biochemistry, University of Leicester, Leicester LE1 9HN (United Kingdom)

    2008-08-01

    Glyceraldehyde-3-phosphate dehydrogenase A has been cloned, expressed and purified. Apoprotein crystals have been grown which diffracted to 1.75 Å resolution and belonged to space group P2{sub 1}; holo crystals were grown in the presence of NADP, diffracted to 2.6 Å resolution and belonged to space group P3{sub 2}. The classical glycolytic pathway contains an NAD-dependent glyceraldehyde-3-phosphate dehydrogenase, with NADP-dependent forms reserved for photosynthetic organisms and archaea. Here, the cloning, expression, purification, crystallization and preliminary X-ray analysis of an NADP-dependent glyceraldehyde-3-phosphate dehydrogenase from Helicobacter pylori is reported; crystals of the protein were grown both in the presence and the absence of NADP.

  18. Over-expression of PsGPD, a mushroom glyceraldehyde-3-phosphate dehydrogenase gene, enhances salt tolerance in rice plants.

    Science.gov (United States)

    Cho, Jung-Il; Lim, Hye-Min; Siddiqui, Zamin Shaheed; Park, Sung-Han; Kim, A-Ram; Kwon, Taek-Ryoun; Lee, Seong-Kon; Park, Soo-Chul; Jeong, Mi-Jeong; Lee, Gang-Seob

    2014-08-01

    Transgenic potatoes expressing glyceraldehyde-3-phosphate dehydrogenase (GPD), isolated from the oyster mushroom, Pleurotus sajor-caju, had increased tolerance to salt stress (Jeong et al. Biochem Biophys Res Commun 278:192-196, 2000). To examine the physiological mechanisms enhancing salt tolerance in GPD-transgenic rice plants, the salt tolerance of five GPD transgenic rice lines (T1-T5) derived from Dongjin rice cultivar were evaluated in a fixed 150 mM saline environment in comparison to two known wild-type rice cultivars, Dongjin (salt sensitive) and Pokali (salt tolerant). Transgenic lines, T2, T3, and T5, had a substantial increase in biomass and relative water content compared to Dongjin. Stomatal conductance and osmotic potential were higher in the GPD transgenic lines and were similar to those in Pokali. The results are discussed based on the comparative physiological response of GPD transgenic lines with those of the salt-sensitive and salt-tolerant rice cultivars.

  19. Effect of Follicular Fluid and Platelet-Activating Factor on Lactate Dehydrogenase C Expression in Human Asthenozoospermic Samples

    Directory of Open Access Journals (Sweden)

    Tahereh Esmaeilpour

    2014-01-01

    Full Text Available Background: Application of follicular fluid (FF and platelet-activating factor (PAF in artificial insemination improves sperm motility. Lactate dehydrogenase C (LDH-C is a key enzyme for sperm motility. In this study, the effects of FF and PAF on the sperm motility index and LDH-C expression were investigated. Moreover, LDH-C expression was compared between asthenozoospermic and normozoospermic samples. Methods: The expression of LDH-C was examined by quantitative real-time polymerase chain reaction (q-RT PCR and western blotting after it was treated with optimized concentrations of FF and PAF in twenty asthenozoospermic samples. Also, LDH-C expression was evaluated in five normozoospermic samples. Results: Samples with 75% FF and 100 nM of PAF had an increase in their percentages of progressive and slowly motile sperms and a decrease in their percentages of non-progressive and non-motile sperms. Moreover, LDH-C mRNA transcripts were not changed following PAF and FF treatment, and LDH-C protein was detected in highly progressive motile specimens treated with FF in the asthenozoospermic samples. Furthermore, LDH-C expression was more detectable in the normal sperms. Conclusion: Our results indicated that PAF had more beneficial effects than FF on sperm motility in the asthenozoospermic samples (P=0.0001, although the LDH-C expressions of the sperms were not changed significantly in both groups. We found no association between LDH-C expression and sperm motility after FF and PAF actions. This finding, however, requires further investigation. The fact that LDH-C protein was detected in the normozoospermic, but not asthenozoospermic, samples could be cited as a reason for the infertility in these patients.

  20. Cloning, sequencing and expression of the Schwanniomyces occidentalis NADP-dependent glutamate dehydrogenase gene.

    Science.gov (United States)

    De Zoysa, P A; Connerton, I F; Watson, D C; Johnston, J R

    1991-08-01

    The cloned NADP-specific glutamate dehydrogenase (GDH) genes of Aspergillus nidulans (gdhA) and Neurospora crassa (am) have been shown to hybridize under reduced stringency conditions to genomic sequences of the yeast Schwanniomyces occidentalis. Using 5' and 3' gene-specific probes, a unique 5.1 kb BclI restriction fragment that encompasses the entire Schwanniomyces sequence has been identified. A recombinant clone bearing the unique BclI fragment has been isolated from a pool of enriched clones in the yeast/E. coli shuttle vector pWH5 by colony hybridization. The identity of the plasmid clone was confirmed by functional complementation of the Saccharomyces cerevisiae gdh-1 mutation. The nucleotide sequence of the Schw. occidentalis GDH gene, which consists of 1380 nucleotides in a continuous reading frame of 459 amino acids, has been determined. The predicted amino acid sequence shows considerable homology with GDH proteins from other fungi and significant homology with all other available GDH sequences.

  1. CLONING, SEQUENCING AND EXPRESSION STUDIES OF THE GENES ENCODING AMICYANIN AND THE BETA-SUBUNIT OF METHYLAMINE DEHYDROGENASE FROM THIOBACILLUS-VERSUTUS

    NARCIS (Netherlands)

    UBBINK, M; VANKLEEF, MAG; KLEINJAN, DJ; HOITINK, CWG; HUITEMA, F; BEINTEMA, JJ; DUINE, JA; CANTERS, GW

    1991-01-01

    The genes encoding amicyanin and the beta-subunit of methylamine dehydrogenase (MADH) from Thiobacillus versutus have been cloned and sequenced. The organization of these genes makes it likely that they are coordinately expressed and it supports earlier findings that the blue copper protein amicyani

  2. Molecular cloning and expression of phosphoglycerate dehydrogenase and phosphoserine aminotransferase in the serine biosynthetic pathway from Acanthamoeba castellanii.

    Science.gov (United States)

    Deng, Yihong; Wu, Duo; Tachibana, Hiroshi; Cheng, Xunjia

    2015-04-01

    Free-living amoebae of the genus Acanthamoeba are widespread protozoans that can cause serious infectious diseases. This study characterised phosphoglycerate dehydrogenase (PGDH) and phosphoserine aminotransferase (PSAT) in the phosphorylated serine biosynthetic pathway of Acanthamoeba castellanii. The PGDH gene encodes a protein of 442 amino acids with a calculated molecular weight of 47.7 kDa and an isoelectric point (pI) of 7.64. Meanwhile, the PSAT gene encodes a protein of 394 amino acids with a calculated molecular weight of 43.8 kDa and a pI of 5.80. Confocal microscopy suggests that PGDH is mainly diffused in the cytoplasm, whereas PSAT is located in the inner part of the cell membrane. The messenger RNA (mRNA) expression levels of PGDH and PSAT vary depending on growth state under consecutive culture conditions. No significant changes in the mRNA expression levels of both PGDH and PSAT occur after the incubation of L-serine with Acanthamoeba. This result indicates that exogenous serine exerts no influence on the expression of these genes and that the so-called feedback inhibition of both PGDH and PSAT in Acanthamoeba differs from that in bacteria or other organisms. We propose that the enzymes in the phosphorylated serine biosynthetic pathway function in amoeba growth and proliferation.

  3. Characterization and expression of NAD(H)-dependent glutamate dehydrogenase genes in Arabidopsis.

    Science.gov (United States)

    Turano, F J; Thakkar, S S; Fang, T; Weisemann, J M

    1997-04-01

    Two distinct cDNA clones encoding NAD(H)-dependent glutamate dehydrogenase (NAD[H]-GDH) in Arabidopsis thaliana were identified and sequenced. The genes corresponding to these cDNA clones were designated GDH1 and GDH2. Analysis of the deduced amino acid sequences suggest that both gene products contain putative mitochondrial transit polypeptides and NAD(H)- and alpha-ketoglutarate-binding domains. Subcellular fractionation confirmed the mitochondrial location of the NAD(H)-GDH isoenzymes. In addition, a putative EF-hand loop, shown to be associated with Ca2+ binding, was identified in the GDH2 gene product but not in the GDH1 gene product. GDH1 encodes a 43.0-kD polypeptide, designated alpha, and GDH2 encodes a 42.5-kD polypeptide, designated beta. The two subunits combine in different ratios to form seven NAD(H)-GDH isoenzymes. The slowest-migrating isoenzyme in a native gel, GDH1, is a homohexamer composed of alpha subunits, and the fastest-migrating isoenzyme, GDH7, is a homohexamer composed of beta subunits. GDH isoenzymes 2 through 6 are heterohexamers composed of different ratios of alpha and beta subunits. NAD(H)-GDH isoenzyme patterns varied among different plant organs and in leaves of plants irrigated with different nitrogen sources or subjected to darkness for 4 d. Conversely, there were little or no measurable changes in isoenzyme patterns in roots of plants treated with different nitrogen sources. In most instances, changes in isoenzyme patterns were correlated with relative differences in the level of alpha and beta subunits. Likewise, the relative difference in the level of alpha or beta subunits was correlated with changes in the level of GDH1 or GDH2 transcript detected in each sample, suggesting that NAD(H)-GDH activity is controlled at least in part at the transcriptional level.

  4. Improved phosphorus acquisition by tobacco through transgenic expression of mitochondrial malate dehydrogenase from Penicillium oxalicum.

    Science.gov (United States)

    Lü, Jun; Gao, Xiaorong; Dong, Zhimin; Yi, Jun; An, Lijia

    2012-01-01

    Phosphorus (P) is an essential nutrient for plant growth and development, but is generally unavailable and inaccessible in soil, since applied P is mostly fixed to aluminium (Al) and ferrum (Fe) in acidic soils and to calcium (Ca) in alkaline soils. Increased organic acid excretion is thought to be one mechanism by which plants use to enhance P uptake. In this study, we overexpressed a mitochondrial malate dehydrogenase (MDH) gene from the mycorrhizal fungi Penicillium oxalicum in tobacco. The MDH activity of transgenic lines was significantly increased compared to that of wild type. Malate content in root exudation of transgenic lines induced in response to P deficiency was 1.3- to 2.9-fold greater than that of wild type under the same condition. Among the transgenic lines that were selected for analysis, one line (M1) showed the highest level of MDH activity and malate exudate. M1 showed a significant increase in growth over wild type, with 149.0, 128.5, and 127.9% increases in biomass, when grown in Al-phosphate, Fe-phosphate, and Ca-phosphate media, respectively. M1 also had better P uptake compared to wild type, with total P content increased by 287.3, 243.5, and 223.4% when grown in Al-phosphate, Fe-phosphate, and Ca-phosphate media, respectively. To our knowledge, this is the first study on improving the ability of a plant to utilize P from Al-phosphate, Fe-phosphate, and Ca-phosphate by manipulating the organic acid metabolism of the plant through genetic engineering.

  5. Molecular alterations and expression of succinate dehydrogenase complex in wild-type KIT/PDGFRA/BRAF gastrointestinal stromal tumors.

    Science.gov (United States)

    Celestino, Ricardo; Lima, Jorge; Faustino, Alexandra; Vinagre, João; Máximo, Valdemar; Gouveia, António; Soares, Paula; Lopes, José Manuel

    2013-05-01

    Gastrointestinal stromal tumors (GISTs) are the most common mesenchymal neoplasms of the gastrointestinal tract, disclosing somatic KIT, PDGFRA and BRAF mutations. Loss of function of succinate dehydrogenase (SDH) complex is an alternative molecular mechanism in GISTs, namely in carriers of germline mutations of the SDH complex that develop Carney-Stratakis dyad characterized by multifocal GISTs and multicentric paragangliomas (PGLs). We studied a series of 25 apparently sporadic primary wild-type (WT) KIT/PDGFRA/BRAF GISTs occurring in patients without personal or familial history of PGLs, re-evaluated clinicopathological features and analyzed molecular alterations and immunohistochemistry expression of SDH complex. As control, we used a series of well characterized 49 KIT/PDGFRA/BRAF-mutated GISTs. SDHB expression was absent in 20% and SDHB germline mutations were detected in 12% of WT GISTs. Germline SDHB mutations were significantly associated to younger age at diagnosis. A significant reduction in SDHB expression in WT GISTs was found when compared with KIT/PDGFRA/BRAF-mutated GISTs. No significant differences were found when comparing DOG-1 and c-KIT expression in WT, SDHB-mutated and KIT/PDGFRA/BRAF-mutated GISTs. Our results confirm the occurrence of germline SDH genes mutations in isolated, apparently sporadic WT GISTs. WT KIT/PDGFRA/BRAF GISTs without SDHB or SDHA/SDHB expression may correspond to Carney-Stratakis dyad or Carney triad. Most importantly, the possibility of PGLs (Carney-Stratakis dyad) and/or pulmonary chondroma (Carney triad) should be addressed in these patients and their kindred.

  6. Enhanced drought and heat stress tolerance of tobacco plants with ectopically enhanced cytokinin oxidase/dehydrogenase gene expression.

    Science.gov (United States)

    Macková, Hana; Hronková, Marie; Dobrá, Jana; Turečková, Veronika; Novák, Ondřej; Lubovská, Zuzana; Motyka, Václav; Haisel, Daniel; Hájek, Tomáš; Prášil, Ilja Tom; Gaudinová, Alena; Štorchová, Helena; Ge, Eva; Werner, Tomáš; Schmülling, Thomas; Vanková, Radomíra

    2013-07-01

    Responses to drought, heat, and combined stress were compared in tobacco (Nicotiana tabacum L.) plants ectopically expressing the cytokinin oxidase/dehydrogenase CKX1 gene of Arabidopsis thaliana L. under the control of either the predominantly root-expressed WRKY6 promoter or the constitutive 35S promoter, and in the wild type. WRKY6:CKX1 plants exhibited high CKX activity in the roots under control conditions. Under stress, the activity of the WRKY6 promoter was down-regulated and the concomitantly reduced cytokinin degradation coincided with raised bioactive cytokinin levels during the early phase of the stress response, which might contribute to enhanced stress tolerance of this genotype. Constitutive expression of CKX1 resulted in an enlarged root system, a stunted, dwarf shoot phenotype, and a low basal level of expression of the dehydration marker gene ERD10B. The high drought tolerance of this genotype was associated with a relatively moderate drop in leaf water potential and a significant decrease in leaf osmotic potential. Basal expression of the proline biosynthetic gene P5CSA was raised. Both wild-type and WRKY6:CKX1 plants responded to heat stress by transient elevation of stomatal conductance, which correlated with an enhanced abscisic acid catabolism. 35S:CKX1 transgenic plants exhibited a small and delayed stomatal response. Nevertheless, they maintained a lower leaf temperature than the other genotypes. Heat shock applied to drought-stressed plants exaggerated the negative stress effects, probably due to the additional water loss caused by a transient stimulation of transpiration. The results indicate that modulation of cytokinin levels may positively affect plant responses to abiotic stress through a variety of physiological mechanisms.

  7. Aldehyde dehydrogenase-expressing colon stem cells contribute to tumorigenesis in the transition from colitis to cancer.

    Science.gov (United States)

    Carpentino, Joseph E; Hynes, Mark J; Appelman, Henry D; Zheng, Tong; Steindler, Dennis A; Scott, Edward W; Huang, Emina H

    2009-10-15

    Patients with chronic ulcerative colitis are at increased risk of developing colorectal cancer. Although current hypotheses suggest that sporadic colorectal cancer is due to inability to control cancer stem cells, the cancer stem cell hypothesis has not yet been validated in colitis-associated cancer. Furthermore, the identification of the colitis to cancer transition is challenging. We recently showed that epithelial cells with the increased expression of aldehyde dehydrogenase in sporadic colon cancer correlate closely with tumor-initiating ability. We sought to determine whether ALDH can be used as a marker to isolate tumor-initiating populations from patients with chronic ulcerative colitis. We used fluorescence-activated cell sorting to identify precursor colon cancer stem cells from colitis patients and report both their transition to cancerous stem cells in xenografting studies as well as their ability to generate spheres in vitro. Similar to sporadic colon cancer, these colitis-derived tumors were capable of propagation as sphere cultures. However, unlike the origins of sporadic colon cancer, the primary colitic tissues did not express any histologic evidence of dysplasia. To elucidate a potential mechanism for our findings, we compared the stroma of these different environments and determined that at least one paracrine factor is up-regulated in the inflammatory and malignant stroma compared with resting, normal stroma. These data link colitis and cancer identifying potential tumor-initiating cells from colitic patients, suggesting that sphere and/or xenograft formation will be useful to survey colitic patients at risk of developing cancer.

  8. PCR-based amplification and heterologous expression of Pseudomonas alcohol dehydrogenase genes from the soil metagenome for biocatalysis.

    Science.gov (United States)

    Itoh, Nobuya; Isotani, Kentaro; Makino, Yoshihide; Kato, Masaki; Kitayama, Kouta; Ishimota, Tuyoshi

    2014-02-05

    The amplification of useful genes from metagenomes offers great biotechnological potential. We employed this approach to isolate alcohol dehydrogenase (adh) genes from Pseudomonas to aid in the synthesis of optically pure alcohols from various ketones. A PCR primer combination synthesized by reference to the adh sequences of known Pseudomonas genes was used to amplify full-length adh genes directly from 17 samples of DNA extracted from soil. Three such adh preparations were used to construct Escherichia coli plasmid libraries. Of the approximately 2800 colonies obtained, 240 putative adh-positive clones were identified by colony-PCR. Next, 23 functional adh genes named using the descriptors HBadh and HPadh were analyzed. The adh genes obtained via this metagenomic approach varied in their DNA and amino acid sequences. Expression of the gene products in E. coli indicated varying substrate specificity. Two representative genes, HBadh-1 and HPadh-24, expressed in E. coli and Pseudomonas putida, respectively, were purified and characterized in detail. The enzyme products of these genes were confirmed to be useful for producing anti-Prelog chiral alcohols.

  9. The expression of a recombinant glycolate dehydrogenase polyprotein in potato (Solanum tuberosum) plastids strongly enhances photosynthesis and tuber yield.

    Science.gov (United States)

    Nölke, Greta; Houdelet, Marcel; Kreuzaler, Fritz; Peterhänsel, Christoph; Schillberg, Stefan

    2014-08-01

    We have increased the productivity and yield of potato (Solanum tuberosum) by developing a novel method to enhance photosynthetic carbon fixation based on expression of a polyprotein (DEFp) comprising all three subunits (D, E and F) of Escherichia coli glycolate dehydrogenase (GlcDH). The engineered polyprotein retained the functionality of the native GlcDH complex when expressed in E. coli and was able to complement mutants deficient for the D, E and F subunits. Transgenic plants accumulated DEFp in the plastids, and the recombinant protein was active in planta, reducing photorespiration and improving CO2 uptake with a significant impact on carbon metabolism. Transgenic lines with the highest DEFp levels and GlcDH activity produced significantly higher levels of glucose (5.8-fold), fructose (3.8-fold), sucrose (1.6-fold) and transitory starch (threefold), resulting in a substantial increase in shoot and leaf biomass. The higher carbohydrate levels produced in potato leaves were utilized by the sink capacity of the tubers, increasing the tuber yield by 2.3-fold. This novel approach therefore has the potential to increase the biomass and yield of diverse crops.

  10. Expression of the betaine aldehyde dehydrogenase gene in barley in response to osmotic stress and abscisic acid.

    Science.gov (United States)

    Ishitani, M; Nakamura, T; Han, S Y; Takabe, T

    1995-01-01

    When subjected to salt stress or drought, some vascular plants such as barley respond with an increased accumulation of the osmoprotectant glycine betaine (betaine), being the last step of betaine synthesis catalyzed by betaine aldehyde dehydrogenase (BADH). We report here cloning and characterization of BADH cDNA from barley, a monocot, and the expression pattern of a BADH transcript. An open reading frame of 1515 bp encoded a protein which showed high homology to BADH enzymes present in other plants (spinach and sugar-beet) and in Escherichia coli. Transgenic tobacco plants harboring the clone expressed high levels of both BADH protein and its enzymatic activity. Northern blot analyses indicated that BADH mRNA levels increased almost 8-fold and 2-fold, respectively, in leaves and roots of barley plants grown in high-salt conditions, and that these levels decreased upon release of the stress, whereas they did not decrease under continuous salt stress. BADH transcripts also accumulate in response to water stress or drought, indicating a common response of the plant to osmotic changes that affect its water status. The addition of abscisic acid (ABA) to plants during growth also increased the levels of BADH transcripts dramatically, although the response was delayed when compared to that found for salt-stressed plants. Removal of plant roots before transferring the plants to high-salt conditions reduced only slightly the accumulation of BADH transcripts in the leaves.

  11. Molecular characterization and expression studies during melon fruit development and ripening of L-galactono-1,4-lactone dehydrogenase

    DEFF Research Database (Denmark)

    Pateraki, Irene; Sanmartin, Maite; Kalamaki, Mary S.

    2004-01-01

    The last step of ascorbic acid (AA) biosynthesis is catalysed by the enzyme L-galactono-1,4-lactone dehydrogenase (GalLDH, EC 1.3.2.3), located on the inner mitochondrial membrane. The enzyme converts L-galactono-1,4-lactone to ascorbic acid (AA). In this work, the cloning and characterization...... of a GalLDH full-length cDNA from melon (Cucumis melo L.) are described. Melon genomic DNA Southern analysis indicated that CmGalLDH was encoded by a single gene. CmGalLDH mRNA accumulation was detected in all tissues studied, but differentially expressed during fruit development and seed germination......GalLDH expression is regulated by light. Finally, various stresses and growth regulators resulted in no significant change in steady state levels of CmGalLDH mRNA in 20-d-old melon seedlings. To the authors' knowledge, this is the first report of GalLDH transcript induction in seed germination and differential gene...

  12. Impact of probiotic-supplemented diet on the expression level of lactate dehydrogenase in the leukocytes of rabbits.

    Science.gov (United States)

    Ghoneim, Magdy A E; Moselhy, Said S

    2014-04-01

    Probiotics are known as living, nonpathogenic microorganisms that colonize the intestine and provide benefit to the host. The present study aims to measure one important energy metabolism-related enzyme activity in blood of rabbits fed on probiotics of recommended concentration. In addition, it also aims for the evaluation of the expression level of lactate dehydrogenase (LDH) enzyme using reverse transcriptase-polymerase chain reaction (RT-PCR) technique. Two groups of rabbits are used: control group receiving normal standardized diet and the other probiotic-supplemented group receiving the same diet containing probiotic, namely, Mega acidophilus (200 million cfu/kg body weight/day) for 4 weeks. The obtained results revealed that the rabbits supplemented with probiotics showed a significant decrease in the levels of serum total cholesterol (TC), triacylglycerol, high-density lipoprotein cholesterol (HDL-c) and low-density lipoprotein cholesterol (LDL-c) when compared with control group. Risk factors detected by measuring TC/HDL-c and LDL-c/HDL-c ratios showed statistically significant decrease in probiotic-supplemented rabbits when compared with control group. In addition, blood glucose and total LDH activity were elevated in probiotic-supplemented rabbits when compared with control group. RT-PCR products of LDH-M gene produced two specific amplicons. One amplicon has the expected size of 243 bp from all samples of rabbits as revealed by GelPro software. The level of LDH-M expression was found to be increased in the probiotic-supplemented group. However, unexpected amplicons are produced at 586 bp in all the samples, which may be a dimeric form of the amplified region. It was concluded that this probiotic blend is beneficiary for the metabolic reactions of lipids in the body. Moreover, LDH expression level can be considered as a biomarker for the effect of probiotic and hence monitoring the metabolic changes as reflected from its administration.

  13. Improved production of 2,3-butanediol in Bacillus amyloliquefaciens by over-expression of glyceraldehyde-3-phosphate dehydrogenase and 2,3-butanediol dehydrogenase.

    Directory of Open Access Journals (Sweden)

    Taowei Yang

    Full Text Available BACKGROUND: Previously, a safe strain, Bacillus amyloliquefaciens B10-127 was identified as an excellent candidate for industrial-scale microbial fermentation of 2,3-butanediol (2,3-BD. However, B. amyloliquefaciens fermentation yields large quantities of acetoin, lactate and succinate as by-products, and the 2,3-BD yield remains prohibitively low for commercial production. METHODOLOGY/PRINCIPAL FINDINGS: In the 2,3-butanediol metabolic pathway, glyceraldehyde-3-phosphate dehydrogenase (GAPDH catalyzes the conversion of 3-phosphate glyceraldehyde to 1,3-bisphosphoglycerate, with concomitant reduction of NAD(+ to NADH. In the same pathway, 2,3-BD dehydrogenase (BDH catalyzes the conversion of acetoin to 2,3-BD with concomitant oxidation of NADH to NAD(+. In this study, to improve 2,3-BD production, we first over-produced NAD(+-dependent GAPDH and NADH-dependent BDH in B. amyloliquefaciens. Excess GAPDH reduced the fermentation time, increased the 2,3-BD yield by 12.7%, and decreased the acetoin titer by 44.3%. However, the process also enhanced lactate and succinate production. Excess BDH increased the 2,3-BD yield by 16.6% while decreasing acetoin, lactate and succinate production, but prolonged the fermentation time. When BDH and GAPDH were co-overproduced in B. amyloliquefaciens, the fermentation time was reduced. Furthermore, in the NADH-dependent pathways, the molar yield of 2,3-BD was increased by 22.7%, while those of acetoin, lactate and succinate were reduced by 80.8%, 33.3% and 39.5%, relative to the parent strain. In fed-batch fermentations, the 2,3-BD concentration was maximized at 132.9 g/l after 45 h, with a productivity of 2.95 g/l·h. CONCLUSIONS/SIGNIFICANCE: Co-overexpression of bdh and gapA genes proved an effective method for enhancing 2,3-BD production and inhibiting the accumulation of unwanted by-products (acetoin, lactate and succinate. To our knowledge, we have attained the highest 2,3-BD fermentation yield thus far

  14. Deficient expression of aldehyde dehydrogenase 1A1 is consistent with increased sensitivity of Gorlin syndrome patients to radiation carcinogenesis.

    Science.gov (United States)

    Wright, Aaron T; Magnaldo, Thierry; Sontag, Ryan L; Anderson, Lindsey N; Sadler, Natalie C; Piehowski, Paul D; Gache, Yannick; Weber, Thomas J

    2015-06-01

    Human phenotypes that are highly susceptible to radiation carcinogenesis have been identified. Sensitive phenotypes often display robust regulation of molecular features that modify biological response, which can facilitate identification of the pathways/networks that contribute to pathophysiological outcomes. Here we interrogate primary dermal fibroblasts isolated from Gorlin syndrome patients (GDFs), who display a pronounced inducible tumorigenic response to radiation, in comparison to normal human dermal fibroblasts (NHDFs). Our approach exploits newly developed thiol reactive probes to define changes in protein thiol profiles in live cell studies, which minimizes artifacts associated with cell lysis. Redox probes revealed deficient expression of an apparent 55 kDa protein thiol in GDFs from independent Gorlin syndrome patients, compared with NHDFs. Proteomics tentatively identified this protein as aldehyde dehydrogenase 1A1 (ALDH1A1), a key enzyme regulating retinoic acid synthesis, and ALDH1A1 protein deficiency in GDFs was confirmed by Western blot. A number of additional protein thiol differences in GDFs were identified, including radiation responsive annexin family members and lamin A/C. Collectively, candidates identified in our study have plausible implications for radiation health effects and cancer susceptibility.

  15. Component co-expression and purification of recombinant human pyruvate dehydrogenase complex from baculovirus infected SF9 cells.

    Science.gov (United States)

    Jiang, Yong; Wang, Juan; Zhang, Guofeng; Oza, Khyati; Myers, Linda; Holbert, Marc A; Sweitzer, Sharon

    2014-05-01

    The mammalian pyruvate dehydrogenase complex (PDC) is a multi-component mitochondrial enzyme that plays a key role in the conversion of pyruvate to acetyl-CoA connecting glycolysis to the citric acid cycle. Recent studies indicate that targeting the regulation of PDC enzymatic activity might offer therapeutic opportunities by inhibiting cancer cell metabolism. To facilitate drug discovery in this area, a well defined PDC sample is needed. Here, we report a new method of producing functional, recombinant, high quality human PDC complex. All five components were co-expressed in the cytoplasm of baculovirus-infected SF9 cells by deletion of the mitochondrial localization signal sequences of all the components and E1a was FLAG-tagged to facilitate purification. The protein FLAG tagged E1a complex was purified using FLAG-M2 affinity resin, followed by Superdex 200 sizing chromatography. The E2 and E3BP components were then Lipoylated using an enzyme based in vitro process. The resulting PDC is over 90% pure and homogenous. This non-phosphorylated, lipoylated human PDC was demonstrated to produce a robust detection window when used to develop an enzyme coupled assay of PDHK.

  16. Cloning, expression and characterization of glycerol dehydrogenase involved in 2,3-butanediol formation in Serratia marcescens H30.

    Science.gov (United States)

    Zhang, Liaoyuan; Xu, Quanming; Peng, Xiaoqian; Xu, Boheng; Wu, Yuehao; Yang, Yulong; Sun, Shujing; Hu, Kaihui; Shen, Yaling

    2014-09-01

    The meso-2,3-butanediol dehydrogenase (meso-BDH) from S. marcescens H30 is responsible for converting acetoin into 2,3-butanediol during sugar fermentation. Inactivation of the meso-BDH encoded by budC gene does not completely abolish 2,3-butanediol production, which suggests that another similar enzyme involved in 2,3-butanediol formation exists in S. marcescens H30. In the present study, a glycerol dehydrogenase (GDH) encoded by gldA gene from S. marcescens H30 was expressed in Escherichia coli BL21(DE3), purified and characterized for its properties. In vitro conversion indicated that the purified GDH could catalyze the interconversion of (3S)-acetoin/meso-2,3-butanediol and (3R)-acetoin/(2R,3R)-2,3-butanediol. (2S,3S)-2,3-Butanediol was not a substrate for the GDH at all. Kinetic parameters of the GDH enzyme showed lower K m value and higher catalytic efficiency for (3S/3R)-acetoin in comparison to those for (2R,3R)-2,3-butanediol and meso-2,3-butanediol, implying its physiological role in favor of 2,3-butanediol formation. Maximum activity for reduction of (3S/3R)-acetoin and oxidations of meso-2,3-butanediol and glycerol was observed at pH 8.0, while it was pH 7.0 for diacetyl reduction. The enzyme exhibited relative high thermotolerance with optimum temperature of 60 °C in the oxidation-reduction reactions. Over 60 % of maximum activity was retained at 70 °C. Additionally, the GDH activity was significantly enhanced for meso-2,3-BD oxidation in the presence of Fe(2+) and for (3S/3R)-acetoin reduction in the presence of Mn(2+), while several cations inhibited its activity, particularly Fe(2+) and Fe(3+) for (3S/3R)-acetoin reduction. The properties provided potential application for single configuration production of acetoin and 2,3-butanediol .

  17. Expression of 11beta-hydroxysteroid dehydrogenase 1 and 2 in subcutaneous adipose tissue of lean and obese women with and without polycystic ovary syndrome

    DEFF Research Database (Denmark)

    Svendsen, P F; Madsbad, S; Nilas, L

    2009-01-01

    OBJECTIVE: To investigate the expression of 11beta-hydroxysteroid dehydrogenase (11beta-HSD) type 1 and 2 and hexose-6-phosphate dehydrogenase (H6PDH) mRNA in subcutaneous abdominal tissue from lean and obese women with and without polycystic ovary syndrome (PCOS), and to investigate...... controls, OC). Subcutaneous adipose tissue was collected from the abdomen. Peripheral insulin sensitivity was assessed by the euglycemic hyperinsulinemic clamp and determined as glucose disposal rate and insulin sensitivity index. Whole-body insulin sensitivity was calculated using homeostasis model......beta-HSD1 mRNA. The subgroups LP and OC had increased 11beta-HSD1 and 11beta-HSD2 mRNA expression compared with LC (Pfat...

  18. Expression, purification, crystallization and preliminary X-ray analysis of an NAD-dependent glyceraldehyde-3-phosphate dehydrogenase from Helicobacter pylori

    Energy Technology Data Exchange (ETDEWEB)

    Elliott, Paul R.; Mohammad, Shabaz; Melrose, Helen J.; Moody, Peter C. E., E-mail: pcem1@leicester.ac.uk [Henry Wellcome Laboratories for Structural Biology, University of Leicester, Leicester LE1 9HN (United Kingdom)

    2008-08-01

    Glyceraldehyde-3-phosphate dehydrogenase B from H. pylori has been cloned, expressed, purified and crystallized in the presence of NAD. Crystals of GAPDHB diffracted to 2.8 Å resolution and belonged to space group P6{sub 5}22, with unit-cell parameters a = b = 166.1, c = 253.1 Å. Helicobacter pylori is a dangerous human pathogen that resides in the upper gastrointestinal tract. Little is known about its metabolism and with the onset of antibiotic resistance new treatments are required. In this study, the expression, purification, crystallization and preliminary X-ray diffraction of an NAD-dependent glyceraldehyde-3-phosphate dehydrogenase from H. pylori are reported.

  19. Regulation of hexokinase and glucose-6-phosphate dehydrogenase genes expression at norm and pathology

    Directory of Open Access Journals (Sweden)

    Marunych R. Yu.

    2013-03-01

    Full Text Available The increasing of glycolysis in tumors under aerobic conditions is known as Warburg phenomenon; the activity of the pentose phosphate pathway increases also significantly. The pentose phosphate pathway and glycolysis, especially their first steps, and the regulatory enzyme 6-phosphofrukto-2-kinase/fructose-2,6-bisphosphatase are influenced by cell signaling systems such as the system of circadian clock, the system of hypoxia-inducible factor and unfolded protein response system, that allow malignant cells to adapt to stress factors such as hypoxia, ischemia and influence of low molecular agents. The review enlightens the impact of signaling systems on the key enzymes of glycolysis and the pentose phosphate pathway gene expression in normal cells and in malignant cells, and their importance for survival of malignant cells under stress conditions.

  20. Widening Spectrum of Cellular and Subcellular Expression of Human GLUD1 and GLUD2 Glutamate Dehydrogenases Suggests Novel Functions.

    Science.gov (United States)

    Spanaki, Cleanthe; Kotzamani, Dimitra; Plaitakis, Andreas

    2017-01-01

    Mammalian glutamate dehydrogenase1 (GDH1) (E.C. 1.4.1.3) is a mitochondrial enzyme that catalyzes the reversible oxidative deamination of glutamate to α-ketoglutarate and ammonia while reducing NAD+ and/or NADP+ to NADH and/or NADPH. It links amino acid with carbohydrate metabolism, contributing to Krebs cycle anaplerosis, energy production, ammonia handling and redox homeostasis. Although GDH1 was one of the first major metabolic enzymes to be studied decades ago, its role in cell biology is still incompletely understood. There is however growing interest in a novel GDH2 isoenzyme that emerged via duplication in primates and underwent rapid evolutionary selection concomitant with prefrontal human cortex expansion. Also, the anaplerotic function of GDH1 and GDH2 is currently under sharp focus as this relates to the biology of glial tumors and other neoplasias. Here we used antibodies specific for human GDH1 (hGDH1) and human GDH2 (hGDH2) to study the expression of these isoenzymes in human tissues. Results revealed that both hGDH1 and hGDH2 are expressed in human brain, kidney, testis and steroidogenic organs. However, distinct hGDH1 and hGDH2 expression patterns emerged. Thus, while the Sertoli cells of human testis were strongly positive for hGDH2, they were negative for hGDH1. Conversely, hGDH1 showed very high levels of expression in human liver, but hepatocytes were virtually devoid of hGDH2. In human adrenals, both hGDHs were densely expressed in steroid-producing cells, with hGDH2 expression pattern matching that of the cholesterol side chain cleavage system involved in steroid synthesis. Similarly in human ovaries and placenta, both hGDH1 and hGDH2 were densely expressed in estrogen producing cells. In addition, hGDH1, being a housekeeping enzyme, was also expressed in cells that lack endocrine function. Regarding human brain, study of cortical sections using immunofluorescence (IF) with confocal microscopy revealed that hGDH1 and hGDH2 were both expressed

  1. Isoepoxydon dehydrogenase (idh) gene expression in relation to patulin production by Penicillium expansum under different temperature and atmosphere.

    Science.gov (United States)

    De Clercq, N; Vlaemynck, G; Van Pamel, E; Van Weyenberg, S; Herman, L; Devlieghere, F; De Meulenaer, B; Van Coillie, E

    2016-03-02

    Penicillium expansum growth and patulin production occur mainly at post-harvest stage during the long-term storage of apples. Low temperature in combination with reduced oxygen concentrations is commonly applied as a control strategy to extend apple shelf life and supply the market throughout the year. Our in vitro study investigated the effect of temperature and atmosphere on expression of the idh gene in relation to the patulin production by P. expansum. The idh gene encodes the isoepoxydon dehydrogenase enzyme, a key enzyme in the patulin biosynthesis pathway. First, a reverse transcription real-time PCR (RT-qPCR) method was optimized to measure accurately the P. expansum idh mRNA levels relative to the mRNA levels of three reference genes (18S, β-tubulin, calmodulin), taking into account important parameters such as PCR inhibition and multiple reference gene stability. Subsequently, two P. expansum field isolates and one reference strain were grown on apple puree agar medium (APAM) under three conditions of temperature and atmosphere: 20 °C - air, 4 °C - air and 4 °C - controlled atmosphere (CA; 3% O2). When P. expansum strains reached a 0.5 and 2.0 cm colony diameter, idh expression and patulin concentrations were determined by means of the developed RT-qPCR and an HPLC-UV method, respectively. The in vitro study showed a clear reduction in patulin production and down-regulation of the idh gene expression when P. expansum was grown under 4 °C - CA. The results suggest that stress (low temperature and oxygen level) caused a delay of the fungal metabolism rather than a complete inhibition of toxin biosynthesis. A good correlation was found between the idh expression and patulin production, corroborating that temperature and atmosphere affected patulin production by acting at the transcriptional level of the idh gene. Finally, a reliable RT-qPCR can be considered as an alternative tool to investigate the effect of control strategies on the toxin formation in

  2. Succinate Dehydrogenase Subunit B (SDHB Is Expressed in Neurofibromatosis 1-Associated Gastrointestinal Stromal Tumors (Gists: Implications for the SDHB Expression Based Classification of Gists

    Directory of Open Access Journals (Sweden)

    Jeanny H. Wang, Jerzy Lasota, Markku Miettinen

    2011-01-01

    Full Text Available Gastrointestinal Stromal Tumor (GIST is the most common mesenchymal tumor of the digestive tract. GISTs develop with relatively high incidence in patients with Neurofibromatosis-1 syndrome (NF1. Mutational activation of KIT or PDGFRA is believed to be a driving force in the pathogenesis of familial and sporadic GISTs. Unlike those tumors, NF1-associated GISTs do not have KIT or PGDFRA mutations. Similarly, no mutational activation of KIT or PDGFRA has been identified in pediatric GISTs and in GISTs associated with Carney Triad and Carney-Stratakis Syndrome. KIT and PDGFRA-wild type tumors are expected to have lesser response to imatinib treatment. Recently, Carney Triad and Carney-Stratakis Syndrome -associated GISTs and pediatric GISTs have been shown to have a loss of expression of succinate dehydrogenase subunit B (SDHB, a Krebs cycle/electron transport chain interface protein. It was proposed that GISTs can be divided into SDHB- positive (type 1, and SDHB-negative (type 2 tumors because of similarities in clinical features and response to imatinib treatment. In this study, SDHB expression was examined immunohistochemically in 22 well-characterized NF1-associated GISTs. All analyzed tumors expressed SDHB. Based on SDHB-expression status, NF1-associated GISTs belong to type 1 category; however, similarly to SDHB type 2 tumors, they do not respond well to imatinib treatment. Therefore, a simple categorization of GISTs into SDHB-positive and-negative seems to be incomplete. A classification based on both SDHB expression status and KIT and PDGFRA mutation status characterize GISTs more accurately and allow subdivision of SDHB-positive tumors into different clinico-genetic categories.

  3. Thermal adaptation of cytoplasmic malate dehydrogenases of eastern Pacific barracuda (Sphyraena spp): the role of differential isoenzyme expression

    Science.gov (United States)

    Lin; Somero

    1995-01-01

    Kinetic properties, electrophoretic patterns and thermal stabilities of cytoplasmic malate dehydrogenases (cMDHs) were compared in Eastern Pacific barracuda (Sphyraena spp) from different latitudes. All tissues of the tropical species S. ensis contained only a single, thermostable form of cMDH. Subtropical (S. lucasana) as well as north (S. argentea) and south (S. idiastes) temperate barracuda contained both thermostable and thermolabile cMDHs, the pattern characteristic of most teleosts. Kinetic studies using unfractioned cMDHs showed that the apparent Michaelis­Menten constant (Km) of cofactor (NADH) increased with temperature, but at the physiological temperatures of the four species, Km of NADH was conserved within a narrow range (20­23 µmol l-1). Thermostable and thermolabile cMDHs were chromatographically separated and compared. Thermolabile cMDHs had higher Km values for NADH at all measurement temperatures than did thermostable cMDHs. Thermolabile cMDHs isolated from congeneric barracuda exhibited similar kinetic properties (Km versus temperature, optimal pH, optimal substrate and cofactor concentrations). Thermostable cMDHs, likewise, were similar among the barracuda. Conservation of Km in the differently thermally adapted barracudas is, therefore, apparently due to adjustments in the ratio of expression of the thermostable and thermolabile isoforms, rather than to temperature-adaptive differences among orthologous homologues, as is commonly found for enzymes encoded by a single gene locus. The effects of temperature on the Km of NADH for isolated thermostable and thermolabile cMDHs of a eurythermal goby, Gillichthys mirabilis, however, were consistent with adaptive change in orthologous homologues of cMDH. The selective basis for the absence of thermolabile cMDH in warm-adapted ectotherms, mammals and birds is discussed.

  4. Expression of Mitochondrial Branched-Chain Aminotransferase and α-Keto-Acid Dehydrogenase in Rat Brain: Implications for Neurotransmitter Metabolism

    Directory of Open Access Journals (Sweden)

    Jeffrey Thomas Cole

    2012-05-01

    Full Text Available In the brain, metabolism of the essential branched chain amino acids (BCAAs leucine, isoleucine and valine, is regulated in part by protein synthesis requirements. Excess BCAAs are catabolized or excreted. The first step in BCAA catabolism is catalyzed by the branched chain aminotransferase (BCAT isozymes, mitochondrial BCATm and cytosolic BCATc. A product of this reaction, glutamate, is the major excitatory neurotransmitter and precursor of the major inhibitory neurotransmitter -aminobutyric acid (GABA. The BCATs are thought to participate in an α-keto-acid nitrogen shuttle that provides nitrogen for synthesis of glutamate from -ketoglutarate. The branched-chain α-keto acid dehydrogenase enzyme complex (BCKDC catalyzes the second and first irreversible step in BCAA metabolism, which is oxidative decarboxylation of the branched-chain α-keto acid (BCKA products of the BCAT reaction. Maple Syrup Urine Disease (MSUD results from genetic defects in BCKDC, which leads to accumulation of toxic levels of BCAAs and BCKAs that result in brain swelling. Immunolocalization of BCATm and BCKDC in rats revealed that BCATm is present in astrocytes in white matter and in neuropil, while BCKDC is expressed only in neurons. BCATm appears uniformly distributed in astrocyte cell bodies throughout the brain. The segregation of BCATm to astrocytes and BCKDC to neurons provides further support for the existence of a BCAA-dependent glial-neuronal nitrogen shuttle since the data show that BCKAs produced by glial BCATm must be exported to neurons. Additionally, the neuronal localization of BCKDC suggests that MSUD is a neuronal defect involving insufficient oxidation of BCKAs, with secondary effects extending beyond the neuron.

  5. Dynamic expression of the retinoic acid-synthesizing enzyme retinol dehydrogenase 10 (rdh10) in the developing mouse brain and sensory organs.

    Science.gov (United States)

    Romand, Raymond; Kondo, Takako; Cammas, Laura; Hashino, Eri; Dollé, Pascal

    2008-06-20

    Organs develop through many tissue interactions during embryogenesis, involving numerous signaling cascades and gene products. One of these signaling molecules is retinoic acid (RA), an active vitamin A derivative, which in mammalian embryos is synthesized from maternal retinol by two oxidative reactions involving alcohol/retinol dehydrogenases (ADH/RDHs) and retinaldehyde dehydrogenases (RALDHs), respectively. The activity of RALDHs is known to be crucial for RA synthesis; however, recently a retinol dehydrogenase (RDH10) has been shown to represent a new limiting factor in this synthesis. We investigated the spatiotemporal distribution of Rdh10 gene transcripts by in situ hybridization and quantitative polymerase chain reaction (PCR) during development of the brain and sensory organs. Although Rdh10 relative mRNA levels decline throughout brain development, we show a strong and lasting expression in the meninges and choroid plexuses. Rdh10 expression is also specifically seen in the striatum, a known site of retinoid signaling. In the eye, regional expression is observed both in the prospective pigmented epithelium and neural retina. In the inner ear Rdh10 expression is specific to the endolymphatic system and later the stria vascularis, both organs being involved in endolymph homeostasis. Furthermore, in the peripheral olfactory system and the vibrissae follicles, expression is present from early stages in regions where sensory receptors appear and mesenchymal/epithelial interactions take place. The distribution of Rdh10 transcripts during brain and sensory organ development is consistent with a role of this enzyme in generating region-specific pools of retinaldehyde that will be used by the various RALDHs to refine the patterns of RA synthesis.

  6. A potato tuber-expressed mNRA with homology to steroid dehydrogenases affects gibberellin levels and plant development

    NARCIS (Netherlands)

    Bachem, C.W.B.; Horvath, B.M.; Trindade, L.M.; Claassens, M.M.J.; Davelaar, E.; Jordi, W.J.R.M.; Visser, R.G.F.

    2001-01-01

    Using cDNA-AFLP RNA fingerprinting throughout potato tuber development, we have isolated a transcript-derived fragment (TDF511) with strong homology to plant steroid dehydrogenases. During in vitro tuberization, the abundance profile of the TDF shows close correlation to the process of tuber formati

  7. Streptomyces coelicolor XdhR is a direct target of (p)ppGpp that controls expression of genes encoding xanthine dehydrogenase to promote purine salvage.

    Science.gov (United States)

    Sivapragasam, Smitha; Grove, Anne

    2016-05-01

    The gene encoding Streptomyces coelicolor xanthine dehydrogenase regulator (XdhR) is divergently oriented from xdhABC, which encodes xanthine dehydrogenase (Xdh). Xdh is required for purine salvage pathways. XdhR was previously shown to repress xdhABC expression. We show that XdhR binds the xdhABC-xdhR intergenic region with high affinity (Kd ∼ 0.5 nM). DNaseI footprinting reveals that this complex formation corresponds to XdhR binding the xdhR gene promoter at two adjacent sites; at higher protein concentrations, protection expands to a region that overlaps the transcriptional and translational start sites of xdhABC. While substrates for Xdh have little effect on DNA binding, GTP and ppGpp dissociate the DNA-XdhR complex. Progression of cells to stationary phase, a condition associated with increased (p)ppGpp production, leads to elevated xdhB expression; in contrast, inhibition of Xdh by allopurinol results in xdhB repression. We propose that XdhR is a direct target of (p)ppGpp, and that expression of xdhABC is upregulated during the stringent response to promote purine salvage pathways, maintain GTP homeostasis and ensure continued (p)ppGpp synthesis. During exponential phase growth, basal levels of xdhABC expression may be achieved by GTP serving as a lower-affinity XdhR ligand.

  8. 4-dihydrotrisporin-dehydrogenase, an enzyme of the sex hormone pathway of Mucor mucedo: purification, cloning of the corresponding gene, and developmental expression.

    Science.gov (United States)

    Wetzel, Jana; Scheibner, Olaf; Burmester, Anke; Schimek, Christine; Wöstemeyer, Johannes

    2009-01-01

    The NADP-dependent 4-dihydrotrisporin-dehydrogenase is a (-) mating-type-specific enzyme in the pathway from beta-carotene to trisporic acid. This substance and its isomers and derivatives represent the general system of sexual communication in zygomycetes. The (-) mating type of Mucor mucedo was stimulated by trisporic acid and the enzyme was purified by ion exchange and affinity chromatography. Several peptides of the 26-kDa protein, digested with trypsin, were sequenced by mass spectrometry. Oligonucleotides based on protein sequence data were used for PCR amplification of genomic DNA. The primary PCR fragment was sequenced and the complete gene, TSP2, was isolated. A labeled TSP2 hybridization probe detects a single-copy gene in the genome of M. mucedo. Northern blot analysis with RNAs from different growth stages reveals that the expression of the gene depends on the developmental stage of the mycelium in both mating types of M. mucedo. At the enzyme level, activity is found exclusively in the (-) mating type. However, renaturation of proteins in sodium dodecyl sulfate-containing gels revealed the TSP2 gene product in both mating types. Analyzing the protein sequence places the enzyme in the short chain dehydrogenase superfamily. Thus, it has an evolutionary origin distinct from that of the previously isolated 4-dihydromethyltrisporate dehydrogenase, which belongs to the aldo/keto reductase superfamily. Apart from the TSP2 genes in the three sequenced zygomycetous genomes (Phycomyces blakesleeanus, Rhizopus oryzae, and Mucor circinelloides), the closest relative is the Myxococcus xanthus CsgA gene product, which is also a short chain dehydrogenase, involved in C signaling and fruiting body formation.

  9. The cinnamyl alcohol dehydrogenase (CAD gene family in flax (Linum usitatissimum L.: Insight from expression profiling of cads induced by elicitors in cultured flax cells

    Directory of Open Access Journals (Sweden)

    Eom Hee Seung

    2016-01-01

    Full Text Available Cinnamyl alcohol dehydrogenase (CAD is a key enzyme in the biosynthesis of lignin and lignans as it catalyzes the final step of monolignol biosynthesis, using NADPH as a cofactor. In higher plants, CAD is encoded by a multigene family consisting of three major classes. Based on the recently released flax (Linum usitatissimum L. whole-genome sequences, in this study we identified six CAD family genes that contain an ADH_N domain and an ADH_zinc_N domain, which suggests that the putative flax CADs (LuCADs are zinc-dependent alcohol dehydrogenases and members of the plant CAD family. In addition, expression analysis using quantitative real-time PCR revealed spatial variations in the expression of LuCADs in different organs. Comparative analysis between LuCAD enzymatic activity and LuCAD transcripts indicates that the variation of LuCAD enzymatic activities by elicitors is reflected by transcription of LuCADs in flax suspension-cultured cells. Taken together, our genome-wide analysis of CAD genes and the expression profiling of these genes provide valuable information for understanding the function of CADs, and will assist future studies on the physiological role of monolignols associated with plant defense.

  10. Alcohol dehydrogenaseexpression correlates with CDR1, CDR2 and FLU1 expression in Candida albicans from patients with vulvovaginal candidiasis

    Institute of Scientific and Technical Information of China (English)

    GUO Hui; ZHANG Xiao-li; GAO Lai-qiang; LI Shui-xiu; SONG Yan-jun; ZHANG Hong

    2013-01-01

    Background The most critical mechanism governing drug resistance in Candida albicans (C.albicans) involves efflux pumps,the functionality of which largely depends on energy metabolism.Alcohol dehydrogenase Ⅰ (ADH1) plays an important role in intracellular energy metabolism.The aim of this study was to explore the relationship between ADH1 and drug resistance in C.albicans.Methods Twenty clinical C.albicans samples isolated from individual patients diagnosed with vulvovaginal candidiasis,and two C.albicans strains obtained from a single parental source (the fluconazole (FLC)-sensitive strain CA-1S and the FLC-resistant strain CA-16R) were included in our study.In accordance with the Clinical and Laboratory Standards Institute (CLSI) M27-A3 guidelines,we used the microdilution method to examine the FLC minimum inhibitory concentrations (MICs) and real-time reverse transcription polymerase chain reaction (RT-PCR) to measure the mRNA expression levels of ADH1 and the azole resistance genes CDR1,CDR2,MDR1,FLU1 and ERG11 in all the isolates.Results A highly significant positive correlation between the mRNA levels of ADH1 and the MICs (rs =0.921,P=0.000),as well as positive correlations between the mRNA level of ADH1 and those of CDR1,CDR2 and FLU1 (rs of 0.704,0.772 and 0.779,respectively,P <0.01),were observed in the 20 clinical C.albicans samples.The relative expression of ADH1 was upregulated 10.63-to 17.61-fold in all of the drug-resistant isolates.No correlations were found between the mRNA levels of ADH1 and those of MDR1 or ERG11 (P >0.05).The mRNA levels of the examined drug resistance genes were higher in the CA-16R strain than in CA-1S,and the mRNA levels of ADH1 in CA-16R were 11.64-fold higher than those in CA-1S (P <0.05).Conclusions These results suggest that high levels of ADH1 transcription are implicated in FLC resistance in C.albicans and that the mRNA expression levels of ADH1 are positively correlated with those of CDR1,CDR2 and FLU1.

  11. Functional characterization and expression analysis of rice δ(1)-pyrroline-5-carboxylate dehydrogenase provide new insight into the regulation of proline and arginine catabolism.

    Science.gov (United States)

    Forlani, Giuseppe; Bertazzini, Michele; Zarattini, Marco; Funck, Dietmar

    2015-01-01

    While intracellular proline accumulation in response to various stress conditions has been investigated in great detail, the biochemistry and physiological relevance of proline degradation in plants is much less understood. Moreover, the second and last step in proline catabolism, the oxidation of δ(1)-pyrroline-5-carboxylic acid (P5C) to glutamate, is shared with arginine catabolism. Little information is available to date concerning the regulatory mechanisms coordinating these two pathways. Expression of the gene coding for P5C dehydrogenase was analyzed in rice by real-time PCR either following the exogenous supply of amino acids of the glutamate family, or under hyperosmotic stress conditions. The rice enzyme was heterologously expressed in E. coli, and the affinity-purified protein was thoroughly characterized with respect to structural and functional properties. A tetrameric oligomerization state was observed in size exclusion chromatography, which suggests a structure of the plant enzyme different from that shown for the bacterial P5C dehydrogenases structurally characterized to date. Kinetic analysis accounted for a preferential use of NAD(+) as the electron acceptor. Cations were found to modulate enzyme activity, whereas anion effects were negligible. Several metal ions were inhibitory in the micromolar range. Interestingly, arginine also inhibited the enzyme at higher concentrations, with a mechanism of uncompetitive type with respect to P5C. This implies that millimolar levels of arginine would increase the affinity of P5C dehydrogenase toward its specific substrate. Results are discussed in view of the involvement of the enzyme in either proline or arginine catabolism.

  12. cDNA Fragment Cloning of L-Galactono-1,4-Lactone Dehydrogenase and It's Expression in Different Organs of R.roxburghii Tratt

    Institute of Scientific and Technical Information of China (English)

    AN Hua-ming; CHEN Li-geng; FAN Wei-guo

    2004-01-01

    A 855 bp cDNA encoding L-galactono-1,4-lactone dehydrogenase (GalLDH) fragment was cloned from fruit of R. roxburghii Tratt by the method of RT-PCR, on the basis of the homologous genes of Arabidopsis thaliana, cauliflower, sweet potato, strawberry, etc. in GenBank. Sequence analysis showed 79-92% identity in nucleotide sequence and 75-87%identity in amino acid sequence to that of strawberry and Arabidopsis thaliana, etc.Northern blot showed that the expression of GalLDH was significantly different in different organs. The transcription level of GalLDH in fruit was significantly higher than that in leaf, stem and root respectively. Furthermore, this expression mode was highly correlated with AsA levels.

  13. Abiotic Stress Generates ROS That Signal Expression of Anionic Glutamate Dehydrogenases to Form Glutamate for Proline Synthesis in Tobacco and Grapevine[W

    Science.gov (United States)

    Skopelitis, Damianos S.; Paranychianakis, Nikolaos V.; Paschalidis, Konstantinos A.; Pliakonis, Eleni D.; Delis, Ioannis D.; Yakoumakis, Dimitris I.; Kouvarakis, Antonios; Papadakis, Anastasia K.; Stephanou, Euripides G.; Roubelakis-Angelakis, Kalliopi A.

    2006-01-01

    Glutamate dehydrogenase (GDH) may be a stress-responsive enzyme, as GDH exhibits considerable thermal stability, and de novo synthesis of the α-GDH subunit is induced by exogenous ammonium and senescence. NaCl treatment induces reactive oxygen species (ROS), intracellular ammonia, expression of tobacco (Nicotiana tabacum cv Xanthi) gdh-NAD;A1 encoding the α-subunit of GDH, increase in immunoreactive α-polypeptide, assembly of the anionic isoenzymes, and in vitro GDH aminating activity in tissues from hypergeous plant organs. In vivo aminating GDH activity was confirmed by gas chromatorgraphy–mass spectrometry monitoring of 15N-Glu, 15N-Gln, and 15N-Pro in the presence of methionine sulfoximine and amino oxyacetic acid, inhibitors of Gln synthetase and transaminases, respectively. Along with upregulation of α-GDH by NaCl, isocitrate dehydrogenase genes, which provide 2-oxoglutarate, are also induced. Treatment with menadione also elicits a severalfold increase in ROS and immunoreactive α-polypeptide and GDH activity. This suggests that ROS participate in the signaling pathway for GDH expression and protease activation, which contribute to intracellular hyperammonia. Ammonium ions also mimic the effects of salinity in induction of gdh-NAD;A1 expression. These results, confirmed in tobacco and grape (Vitis vinifera cv Sultanina) tissues, support the hypothesis that the salinity-generated ROS signal induces α-GDH subunit expression, and the anionic iso-GDHs assimilate ammonia, acting as antistress enzymes in ammonia detoxification and production of Glu for Pro synthesis. PMID:17041150

  14. Clinical significance of the thymidylate synthase, dihydropyrimidine dehydrogenase, and thymidine phosphorylase mRNA expressions in hepatocellular carcinoma patients receiving 5-fluorouracil-based transarterial chemoembolization treatment

    Directory of Open Access Journals (Sweden)

    Zhao H

    2013-07-01

    Full Text Available Hongyun Zhao,1,* Yuanyuan Zhao,2,* Ying Guo,1 Yan Huang,2 Suxia Lin,3 Cong Xue,2 Fei Xu,2 Yang Zhang,1 Liping Zhao,2 Zhihuang Hu,2 Li Zhang1,2 1State Key Laboratory of Oncology in South China and National Anti-Cancer Drug Clinical Research Centre, 2State Key Laboratory of Oncology in South China and Department of Medical Oncology, 3Department of Pathological Oncology, Sun Yat-sen University Cancer Center, Guangzhou, People's Republic of China*These authors contributed equally to this workPurpose: To determine whether 5-fluorouracil (5-FU sensitivity is associated with the mRNA expressions of thymidylate synthase (TS, dihydropyrimidine dehydrogenase (DPD, and thymidine phosphorylase (TP in patients with hepatocellular carcinoma (HCC treated with 5-FU-based transarterial chemoembolization (TACE.Methods: Formalin-fixed, paraffin-embedded tumor specimens from 40 patients treated with 5-FU-based TACE were selected for the examination of TS, DPD, and TP expression level by a quantitative real-time reverse transcription- polymerase chain reaction (PCR technique. Patients were categorized into high and low expression groups according to the median expression level of each enzyme. Associations between the mRNA expression levels of TS, DPD, and TP and clinical parameters including treatment efficacies, clinicopathological factors, and prognosis were assessed.Results: High DPD expression was associated with worse treatment outcome, including intrahepatic disease progression rate (hazard ratio [HR] for high DPD versus low DPD, 2.212; 95% confidence interval [CI], 1.030–4.753; P = 0.042, extrahepatic disease progression rate (HR for high versus low DPD, 3.171; 95% CI, 1.003–10.023; P = 0.049, and progression-free survival (HR for high versus low DPD, 2.308; 95% CI, 1.102–4.836; P = 0.027. No correlation was found between the mRNA expression of TS/TP and treatment outcome.Conclusion: DPD mRNA expression level was negatively correlated with the clinical

  15. Stereoselective synthesis of (R)-phenylephrine using recombinant Escherichia coli cells expressing a novel short-chain dehydrogenase/reductase gene from Serratia marcescens BCRC 10948.

    Science.gov (United States)

    Peng, Guan-Jhih; Kuan, Yi-Chia; Chou, Hsiao-Yi; Fu, Tze-Kai; Lin, Jia-Shin; Hsu, Wen-Hwei; Yang, Ming-Te

    2014-01-20

    (R)-Phenylephrine [(R)-PE] is an α1-adrenergic receptor agonist and is widely used as a nasal decongestant to treat the common cold without the side effects of other ephedrine adrenergic drugs. We identified a short-chain dehydrogenase/reductase (SM_SDR) from Serratia marcescens BCRC 10948 that was able to convert 1-(3-hydroxyphenyl)-2-(methylamino) ethanone (HPMAE) into (R)-PE. The SM_SDR used NADPH and NADH as cofactors with specific activities of 17.35±0.71 and 5.57±0.07mU/mg protein, respectively, at 30°C and pH 7.0, thereby indicating that this enzyme could be categorized as an NADPH-preferring short-chain dehydrogenase/reductase. Escherichia coli strain BL21 (DE3) expressing SM_SDR could convert HPMAE into (R)-PE with more than 99% enantiomeric excess. The productivity and conversion yield were 0.57mmolPE/lh and 51.06%, respectively, using 10mM HPMAE. Fructose was the most effective carbon source for the conversion of HPMAE to (R)-PE.

  16. Expression of a heat-stable NADPH-dependent alcohol dehydrogenase from Thermoanaerobacter pseudethanolicus 39E in Clostridium thermocellum 1313 results in increased hydroxymethylfurfural resistance

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Sun-Ki; Groom, Joseph; Chung, Daehwan; Elkins, James; Westpheling, Janet

    2017-03-15

    Resistance to deconstruction is a major limitation to the use of lignocellulosic biomass as a substrate for the production of fuels and chemicals. Consolidated bioprocessing (CBP), the use of microbes for the simultaneous hydrolysis of lignocellulose into soluble sugars and fermentation of the resulting sugars to products of interest, is a potential solution to this obstacle. The pretreatment of plant biomass, however, releases compounds that are inhibitory to the growth of microbes used for CBP. Heterologous expression of the Thermoanaerobacter pseudethanolicus 39E bdhA gene, that encodes an alcohol dehydrogenase, in Clostridium thermocellum significantly increased resistance to furan derivatives at concentrations found in acid-pretreated biomass. The mechanism of detoxification of hydroxymethylfurfural was shown to be primarily reduction using NADPH as the cofactor. In addition, we report the construction of new expression vectors for homologous and heterologous expression in C. thermocellum. These vectors use regulatory signals from both C. bescii (the S-layer promoter) and C. thermocellum (the enolase promoter) shown to efficiently drive expression of the BdhA enzyme. Toxic compounds present in lignocellulose hydrolysates that inhibit cell growth and product formation are obstacles to the commercialization of fuels and chemicals from biomass. Expression of genes that reduce the effect of these inhibitors, such as furan derivatives, will serve to enable commercial processes using plant biomass for the production of fuels and chemicals.

  17. Expression of the human isoform of glutamate dehydrogenase, hGDH2, augments TCA cycle capacity and oxidative metabolism of glutamate during glucose deprivation in astrocytes.

    Science.gov (United States)

    Nissen, Jakob D; Lykke, Kasper; Bryk, Jaroslaw; Stridh, Malin H; Zaganas, Ioannis; Skytt, Dorte M; Schousboe, Arne; Bak, Lasse K; Enard, Wolfgang; Pääbo, Svante; Waagepetersen, Helle S

    2017-03-01

    A key enzyme in brain glutamate homeostasis is glutamate dehydrogenase (GDH) which links carbohydrate and amino acid metabolism mediating glutamate degradation to CO2 and expanding tricarboxylic acid (TCA) cycle capacity with intermediates, i.e. anaplerosis. Humans express two GDH isoforms, GDH1 and 2, whereas most other mammals express only GDH1. hGDH1 is widely expressed in human brain while hGDH2 is confined to astrocytes. The two isoforms display different enzymatic properties and the nature of these supports that hGDH2 expression in astrocytes potentially increases glutamate oxidation and supports the TCA cycle during energy-demanding processes such as high intensity glutamatergic signaling. However, little is known about how expression of hGDH2 affects the handling of glutamate and TCA cycle metabolism in astrocytes. Therefore, we cultured astrocytes from cerebral cortical tissue of hGDH2-expressing transgenic mice. We measured glutamate uptake and metabolism using [(3) H]glutamate, while the effect on metabolic pathways of glutamate and glucose was evaluated by use of (13) C and (14) C substrates and analysis by mass spectrometry and determination of radioactively labeled metabolites including CO2 , respectively. We conclude that hGDH2 expression increases capacity for uptake and oxidative metabolism of glutamate, particularly during increased workload and aglycemia. Additionally, hGDH2 expression increased utilization of branched-chain amino acids (BCAA) during aglycemia and caused a general decrease in oxidative glucose metabolism. We speculate, that expression of hGDH2 allows astrocytes to spare glucose and utilize BCAAs during substrate shortages. These findings support the proposed role of hGDH2 in astrocytes as an important fail-safe during situations of intense glutamatergic activity. GLIA 2017;65:474-488.

  18. Expression of the succinate dehydrogenase genes (sdhCAB) from the facultatively anaerobic paenibacillus macerans during aerobic growth

    Science.gov (United States)

    Schirawski; Hankeln; Unden

    1998-10-01

    Paenibacillus (formerly Bacillus) macerans is capable of succinate oxidation under oxic conditions and fumarate reduction under anoxic conditions. The reactions are catalyzed by different enzymes, succinate dehydrogenase (Sdh) and fumarate reductase (Frd). The genes encoding Sdh (sdhCAB) were analyzed. The gene products of sdhA and sdhB were similar to the subunits of known Sdh and Frd enzymes. The hydrophobic subunit SdhC showed close sequence similarity to the class of Sdh/Frd enzymes containing diheme cytochrome b. From the sdhCAB gene cluster two transcripts were produced, one comprising sdhCAB, the other sdhAB. The transcripts were found only during aerobic growth, and the amount was directly proportional to Sdh activity, but inversely proportional to Frd activity.

  19. RNA expression and chromosomal location of the mouse long-chain acyl-CoA dehydrogenase gene

    Energy Technology Data Exchange (ETDEWEB)

    Hinsdale, M.E.; Farmer, S.C.; Hamm, D.A.; Tolwani, R.J.; Wood, P.A. [Univ. of Alabama, Birmingham, AL (United States)] [and others

    1995-07-20

    The cDNA for mouse long-chain acyl-CoA dehydrogenase (Acadl, gene symbol; LCAD, enzyme) was cloned and characterized. The cDNA was obtained by library screening and reverse transcription-polymerase chain reaction (RT-PCR). The deduced amino acid sequence showed a high degree of homology to both the rat and the human LCAD sequence. Northern analysis of multiple tissues using the mouse Acadl cDNA as a probe showed two bands in all tissues examined. We found a total of three distinct mRNAs for Acadl. These three mRNAs were encoded by a single gene that we mapped to mouse chromosome 1. The three transcripts differed in the 3{prime} untranslated region due to use of alternative polyadenylation sites. Quantitative evaluation of a multitissue Northern blot showed a varied ratio of the larger transcript as compared with the smaller transcripts. 40 refs., 6 figs., 1 tab.

  20. Expression of 3β-hydroxysteroid dehydrogenase in ovarian and uterine tissue during diestrus and open cervix cystic endometrial hyperplasia-pyometra in the bitch.

    Science.gov (United States)

    Gultiken, Nilgun; Yarim, Murat; Yarim, Gul Fatma; Gacar, Ayhan; Mason, James Ian

    2016-07-15

    The purpose of this study was to compare the expression of 3β-hydroxystreroid dehydrogenase (3β-HSD) in the uterus and ovary of healthy dogs and those with cystic endometrial hyperplasia and/or pyometra complex (CEH-pyometra). Eighteen female dogs were included in the study. Eleven bitches with open cervix CEH-pyometra were included in the CEH-pyometra group and seven diestrus bitches in the control group. For immunostaining a rabbit polyclonal, one raised against recombinant human type 2 (adrenal/gonadal) 3β-HSD was used. Progesterone (P4) concentrations were not statistically different between the groups. Strongly stained large interstitial cell groups in the ovarian medulla were observed particularly in CEH-pyometra group although these cells in the control group were weakly or moderately stained and existed singly or paired. The expressions of 3β-HSD in luminal epithelium (42.40 ± 22.40% vs. 18.42 ± 13.15%, P  0.05). Similarly, the significant increase in the expression of 3β-HSD in ovarian interstitial cells (33.86 ± 29.44 vs. 1.13 ± 2.97, P < 0.05) was found in CEH-pyometra group compared to the control group. The study revealed that 3β-HSD expression in the endometrium of canine CEH-pyometra was significantly high.

  1. The NADP-dependent glutamate dehydrogenase gene from the astaxanthin producer Xanthophyllomyces dendrorhous: use of Its promoter for controlled gene expression.

    Science.gov (United States)

    Rodríguez-Sáiz, Marta; Godio, Ramiro P; Alvarez, Vanessa; de la Fuente, Juan Luis; Martín, Juan F; Barredo, José Luis

    2009-02-01

    The gdhA gene encoding the NADP-dependent glutamate dehydrogenase (GDH) activity from Xanthophyllomyces dendrorhous has been cloned and characterized, and its promoter used for controlled gene expression in this red-pigmented heterobasidiomycetous yeast. We determined the nucleotide sequence of a 4701 bp DNA genomic fragment, showing an open reading frame of 1871 bp interrupted by five introns with fungal consensus splice-site junctions. The predicted protein (455 amino acids; 49 kDa) revealed high identity to GDHs, especially to those from the fungi Cryptococcus neoformans (70%), Sclerotinia sclerotiorum (66%), and several species of Aspergillus (66-67%). Gene phylogenies support the grouping of X. dendrorhous GDH close to those from the majority of the filamentous fungi. The promoter region of the gdhA gene (PgdhA) contains a TATA-like box and two large pyrimidine stretches. The use of PgdhA for gene expression was validated by electrotransformation of X. dendrorhous using an in-frame fusion with the hygromycin resistance gene (hygR) as a reporter. X. dendrorhous transformants were able to grow in YEME complex medium and in Czapek minimal medium supplemented with 50 microg/ml hygromycin, but gene expression in Czapek medium was repressed when using ammonium acetate as a nitrogen source. PgdhA is a valuable tool for controlled gene expression in Basidiomycetes.

  2. Reactive oxygen species (ROS) production triggered by prostaglandin D2 (PGD2) regulates lactate dehydrogenase (LDH) expression/activity in TM4 Sertoli cells.

    Science.gov (United States)

    Rossi, Soledad P; Windschüttl, Stefanie; Matzkin, María E; Rey-Ares, Verónica; Terradas, Claudio; Ponzio, Roberto; Puigdomenech, Elisa; Levalle, Oscar; Calandra, Ricardo S; Mayerhofer, Artur; Frungieri, Mónica B

    2016-10-15

    Reactive oxygen species (ROS) regulate testicular function in health and disease. We previously described a prostaglandin D2 (PGD2) system in Sertoli cells. Now, we found that PGD2 increases ROS and hydrogen peroxide (H2O2) generation in murine TM4 Sertoli cells, and also induces antioxidant enzymes expression suggesting that defense systems are triggered as an adaptive stress mechanism that guarantees cell survival. ROS and specially H2O2 may act as second messengers regulating signal transduction pathways and gene expression. We describe a stimulatory effect of PGD2 on lactate dehydrogenase (LDH) expression via DP1/DP2 receptors, which is prevented by the antioxidant N-acetyl-L-cysteine and the PI3K/Akt pathway inhibitor LY 294002. PGD2 also enhances Akt and CREB/ATF-1 phosphorylation. Our results provide evidence for a role of PGD2 in the regulation of the oxidant/antioxidant status in Sertoli cells and, more importantly, in the modulation of LDH expression which takes place through ROS generation and the Akt-CREB/ATF-1 pathway.

  3. Efficient expression, purification, and characterization of a novel FAD-dependent glucose dehydrogenase from Aspergillus terreus in Pichia pastoris.

    Science.gov (United States)

    Yang, Yufeng; Huang, Lei; Wang, Jufang; Wang, Xiaoning; Xu, Zhinan

    2014-11-28

    Flavin adenine dinucleotide-dependent glucose dehydrogenase (FAD-GDH) can utilize a variety of external electron acceptors and also has stricter substrate specificity than any other glucose oxidoreductases, which makes it the ideal diagnostic enzyme in the field of glucose biosensors. A gene coding for a hypothetical protein, similar to glucose oxidase and derived from Aspergillus terreus NIH2624, was overexpressed in Pichia pastoris GS115 under the control of an AOX1 promoter with a level of 260,000 U/l in the culture supernatant after fed-batch cultivation for 84 h. After a three-step purification protocol that included isopropanol precipitation, affinity chromatography, and a second isopropanol precipitation, recombinant FAD-GDH was purified with a recovery of 65%. This is the first time that isopropanol precipitation has been used to concentrate a fermentation supernatant and exchange buffers after affinity chromatography purification. The purified FAD-GDH exhibited a broad and diffuse band between 83 and 150 kDa. The recombinant FAD-GDH was stable across a wide pH range (3.5 to 9.0) with maximum activity at pH 7.5 and 55°C. In addition, it displayed very high thermal stability, with a half-life of 82 min at 60°C. These characteristics indicate that FAD-GDH will be useful in the field of glucose biosensors.

  4. Repeated maternal dexamethasone treatments in late gestation increases 11beta-hydroxysteroid dehydrogenase type 1 expression in the hippocampus of the newborn rat.

    Science.gov (United States)

    Wan, Shunlun; Hao, Rusong; Sun, Kang

    This study was designed to investigate the effect of repeated maternal injections of dexamethasone in late gestation on the expression of newborn hippocampal 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1), the enzyme amplifying glucocorticoids' action by converting biologically inactive 11-ketone metabolites into active glucocorticoids. Daily dexamethasone treatments (0.10 mg/kg body weight) in the last week of gestation were carried out in the pregnant rat. The expression of 11beta-HSD1 in the newborn hippocampal tissue was analyzed with Western blot and real-time polymerase chain reaction (PCR). The effect of corticosterone on the expression of 11beta-HSD1 was studied in cultured hippocampal neurons derived from newborn offspring received prenatal dexamethasone treatments. Both body and brain weights of the offspring were reduced significantly by repeated dexamethasone treatments in the last week of gestation. Western blot and real-time PCR analysis showed that both 11beta-HSD1 protein and mRNA expressions were increased significantly in the hippocampus of the newborn offspring on the first and seventh days after birth. Corticosterone could induce 11beta-HSD1 expression in cultured hippocampal neurons prepared from newborns received prenatal dexamethasone treatments, which was blocked by glucocorticoid receptor antagonist RU38486. The above findings suggest that repeated prenatal dexamethasone treatments at the end of gestation increase 11beta-HSD1 expression in the hippocampal tissue of the offspring, which may trigger a positive feedback pathway for the generation of biologically active glucocorticoids in the hippocampal tissue of the newborns.

  5. Expression of 11β-hydroxysteroid dehydrogenase type 1 and glucocorticoid receptors in reproductive tissue of male horses at different stages of sexual maturity.

    Science.gov (United States)

    Herrera-Luna, C V; Budik, S; Helmreich, M; Walter, I; Aurich, C

    2013-04-01

    Glucocorticoids (GCs) as mediators of the stress response may affect Leydig cell function by inhibiting either luteinizing hormone receptor expression or testosterone biosynthesis. The isozymes 11β-hydroxysteroid dehydrogenase (11βHSD) 1 and 11βHSD2 control the intracellular cortisol levels. Little is known about the effects of stress on fertility in the equine. The objective of the present study was to determine the presence and cellular localization of glucocorticoid receptors (GCR) and glucocorticoid-metabolizing enzymes (11βHSD1 and 11βHSD2) in equine epididymal and testicular tissue with special regard to sexual maturation. Testicular and epididymal tissue was collected from 21 healthy stallions, and four age groups were designed: pre-pubertal, young, mature and older horses. Immunohistochemistry (IHC) analysis and quantitative real-time PCR (qRT-PCR) were used. Pre-pubertal horses showed higher testicular gene expression of 11βHSD1, 11βHSD2 and GCR than horses of all other groups (p horses. In mature stallions, expression of 11βHSD enzymes and the oxidative 11βHSD activity in Leydig cells and epididymal basal and principal cells suggest a protective role on these tissues contributing to physiological intracellular glucocorticoid concentrations.

  6. Transcriptional Regulation of Expression of the Maize Aldehyde Dehydrogenase 7 Gene (ZmALDH7B6) in Response to Abiotic Stresses

    Institute of Scientific and Technical Information of China (English)

    GU Ri-liang

    2014-01-01

    Aldehyde dehydrogenases (ALDHs) represent a large protein family, which includes several members that catalyze the oxidation of an aldehyde to its corresponding carboxylic acid in plants. Genes encoding members of theALDH7 subfamily have been suggested to play important roles in various stress adaptations in plants. In this study, quantitative RT-PCR analysis revealed that a maizeALDH7 subfamily member (ZmALDH7B6) was constitutively expressed in various organs, including roots, leaves, immature ears, tassels, and developing seeds. The abundance ofZmALDH7B6 mRNA transcripts in maize roots was increased by ammonium, NaCl, and mannitol treatments. To further analyze tissue-speciifc and stress-induced expression patterns, the 1.5-kb 5´-lfankingZmALDH7B6 promoter region was fused to the β-glucuronidase (GUS) reporter gene and introduced into maize plants. In roots of independent transgenic lines, there was signiifcant induction of GUS activity in response to ammonium supply, conifrming ammonium-dependent expression ofZmALDH7B6 at the transcript level. Histochemical staining showed that GUS activity driven by theZmALDH7B6 promoter was mainly localized in the vascular tissues of maize roots. These results suggested thatZmALDH7B6 is induced by multiple environmental stresses in maize roots, and may play a role in detoxifying aldehydes, particularly in vascular tissue.

  7. Cloning and Expression Analysis of Malate Dehydrogenase Gene from Cassava%木薯苹果酸脱氢酶基因克隆和表达分析

    Institute of Scientific and Technical Information of China (English)

    尹奇; 仝征; 贺庭琪; 王力敏; 黄启星; 郭运玲; 孔华; 王旭初; 郭安平

    2013-01-01

    为从木薯块根中获得苹果酸脱氢酶(MDH)基因,并研究其在转录水平的表达变化规律,利用RACE技术从木薯“华南8号”块根中克隆得到了苹果酸脱氢酶基因,其cDNA全长1 175 bp,包含999 bp的开放阅读框,共编码332个氨基酸.从木薯“华南8号”中获得的MDH氨基酸序列,与其它物种的该序列相似度达84%~94%,包含细胞质苹果酸脱氢酶中高度保守的NAD结合基元“TGAAGQI”和催化基元“IWGNH”.木薯MDH基因与块根淀粉合成相关,在块根发育前期表达量较低,膨大期表达量较高,膨大后期表达量逐渐降低.%A 1 175 bp cDNA sequence of MDH with a 999 bp open reading frame,encoding a protein with 332 amino acids,was obtained from cassava SC8 roots by RACE (rapid-amplification of cDNA ends) to study the expressional pattern of malate dehydrogenase (MDH) mRNA.The MDH shared 84%~94% of amino acid sequence identities with MDH from other species,and contained a typical NAD+ binding motif (TGAAGQI) and a catalytic motif (IWGNH),suggesting it was a cytosolic molate dehydrogenase (cyMDH) gene.MDH was perhaps involved in the process of starch accumulation in cassava,the expression of cassava MDH was up regulated during storage root thinckening.

  8. Improved tolerance to various abiotic stresses in transgenic sweet potato (Ipomoea batatas expressing spinach betaine aldehyde dehydrogenase.

    Directory of Open Access Journals (Sweden)

    Weijuan Fan

    Full Text Available Abiotic stresses are critical delimiters for the increased productivity and cultivation expansion of sweet potato (Ipomoea batatas, a root crop with worldwide importance. The increased production of glycine betaine (GB improves plant tolerance to various abiotic stresses without strong phenotypic changes, providing a feasible approach to improve stable yield production under unfavorable conditions. The gene encoding betaine aldehyde dehydrogenase (BADH is involved in the biosynthesis of GB in plants, and the accumulation of GB by the heterologous overexpression of BADH improves abiotic stress tolerance in plants. This study is to improve sweet potato, a GB accumulator, resistant to multiple abiotic stresses by promoted GB biosynthesis. A chloroplastic BADH gene from Spinacia oleracea (SoBADH was introduced into the sweet potato cultivar Sushu-2 via Agrobacterium-mediated transformation. The overexpression of SoBADH in the transgenic sweet potato improved tolerance to various abiotic stresses, including salt, oxidative stress, and low temperature. The increased BADH activity and GB accumulation in the transgenic plant lines under normal and multiple environmental stresses resulted in increased protection against cell damage through the maintenance of cell membrane integrity, stronger photosynthetic activity, reduced reactive oxygen species (ROS production, and induction or activation of ROS scavenging by the increased activity of free radical-scavenging enzymes. The increased proline accumulation and systemic upregulation of many ROS-scavenging genes in stress-treated transgenic plants also indicated that GB accumulation might stimulate the ROS-scavenging system and proline biosynthesis via an integrative mechanism. This study demonstrates that the enhancement of GB biosynthesis in sweet potato is an effective and feasible approach to improve its tolerance to multiple abiotic stresses without causing phenotypic defects. This strategy for trait

  9. Caenorhabditis elegans expressing the Saccharomyces cerevisiae NADH alternative dehydrogenase Ndi1p, as a tool to identify new genes involved in complex I related diseases

    Directory of Open Access Journals (Sweden)

    Raynald eCossard

    2015-06-01

    Full Text Available Isolated complex I deficiencies are one of the most commonly observed biochemical features in patients suffering from mitochondrial disorders. In the majority of these clinical cases the molecular bases of the diseases remain unknown suggesting the involvement of unidentified factors that are critical for complex I function.The Saccharomyces cerevisiae NDI1 gene, encoding the mitochondrial internal NADH dehydrogenase was previously shown to complement a complex I deficient strain in Caenorhabitis elegans with notable improvements in reproduction, whole organism respiration. These features indicate that Ndi1p can functionally integrate the respiratory chain, allowing complex I deficiency complementation. Taking into account the Ndi1p ability to bypass complex I, we evaluate the possibility to extend the range of defects/mutations causing complex I deficiencies that can be alleviated by NDI1 expression.We report here that NDI1 expressing animals unexpectedly exhibit a slightly shortened lifespan, a reduction in the progeny and a depletion of the mitochondrial genome. However, Ndi1p is expressed and targeted to the mitochondria as a functional protein that confers rotenone resistance to those animals and without affecting their respiration rate and ATP content.We show that the severe embryonic lethality level caused by the RNAi knockdowns of complex I structural subunit encoding genes (e.g. NDUFV1, NDUFS1, NDUFS6, NDUFS8 or GRIM-19 human orthologs in wild type animals is significantly reduced in the Ndi1p expressing worm.All together these results open up the perspective to identify new genes involved in complex I function, assembly or regulation by screening an RNAi library of genes leading to embryonic lethality that should be rescued by NDI1 expression.

  10. High Level Expression of Glucose-6-phosphate Dehydrogenase Gene PsG6PDH from Populus suaveolens in E. coli

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    In order to investigate the functions of the gene PsG6PDH and the mechanisms underlying freezing tolerance of Populus suaveolens, the recombinant expression vector pET-G (pET30a-G6PDH), which contained full encoding region of PsG6PDH gene, was established. The recombinant was identified by lawn-PCR and double enzyme digestion and then transformed into expression host XA90 and induced by isopropyl-a-D-thiogalactoside (IPTG) to express 100 kD polypeptide of G6PDH fusion protein. The results showed that the expressed amount of the fusion protein culminated after 1 mmol·L-1 IPTG treatment for 4 h and that pET-G product was predominately soluble and not extra-cellular secreting.

  11. Exploring the potential of the glycerol-3-phosphate dehydrogenase 2 (GPD2) promoter for recombinant gene expression in Saccharomyces cerevisiae

    DEFF Research Database (Denmark)

    Knudsen, Jan Dines; Johanson, Ted; Eliasson Lantz, Anna

    2015-01-01

    by placing it in strains with different ability to reoxidise NADH, and applying different environmental conditions. Flow cytometric analysis of reporter strains expressing green fluorescent protein (GFP) under the control of the GPD2 promoter was used to determine the promoter activity at the single...... mapping revealed conditions where the GPD2 promoter was either completely inactive or hyperactive, which has implications for its implementation in future biotechnological applications such as for process control of heterologous gene expression....

  12. Expression of aldehyde dehydrogenase family 1 member A1 and high mobility group box 1 in oropharyngeal squamous cell carcinoma in association with survival time.

    Science.gov (United States)

    Qian, Xu; Coordes, Annekatrin; Kaufmann, Andreas M; Albers, Andreas E

    2016-11-01

    Despite the development of novel multimodal treatment combinations in advanced oropharyngeal squamous cell carcinoma (OSCC), outcomes remain poor. The identification of specifically validated biomarkers is required to understand the underlying molecular mechanisms, to evaluate treatment efficiency and to develop novel therapeutic targets. The present study, therefore, examined the presence of aldehyde dehydrogenase family 1 member A1 (ALDH1A1) and high mobility group box 1 (HMGB1) expression in primary OSCC and analyzed the impact on survival time. In 59 patients with OSCC, the expression of ALDH1A1, p16 and HMGB1, and their clinicopathological data were analyzed. HMGB1 positivity was significantly increased in patients with T1-2 stage disease compared with T3-4 stage disease (P<0.001), whereas ALDH1A1 positivity was not. ALDH1A1(+) tumors showed significantly lower differentiation than ALDH1A1(-) tumors (P=0.018). Multivariate analysis showed that ALDH1A1 positivity (P=0.041) and nodal status (N2-3) (P=0.036) predicted a poor prognosis. In this patient cohort, ALDH1A1 and nodal status were identified as independent predictors of a shorter overall survival time. The study results, therefore, provide evidence of the prognostic value of ALDH1A1 as a marker for cancer stem cells and nodal status in OSCC patients.

  13. Identification and mRNA expression of two 17β-hydroxysteroid dehydrogenase genes in the marine mussel Mytilus galloprovincialis following exposure to endocrine disrupting chemicals.

    Science.gov (United States)

    Zhang, Yingying; Wang, Qing; Ji, Yinglu; Zhang, Qian; Wu, Huifeng; Xie, Jia; Zhao, Jianmin

    2014-05-01

    17β-Hydroxysteroid dehydrogenases (17β-HSDs) are multifunctional enzymes involved in the metabolism of steroids, fatty acids, retinoids and bile acid. In this study, two novel types of 17β-HSDs (named as MgHsd17b10 and MgHsd17b12) were cloned from Mytilus galloprovincialis by using rapid amplification of cDNA ends (RACE) approaches. Sequence analysis showed that MgHsd17b10 and MgHsd17b12 encoded a polypeptide of 259 and 325 amino acids, respectively. Phylogenetic analysis revealed that MgHsd17b10 and MgHsd17b12 were evolutionarily clustered with other invertebrate 17β-HSD type 10 and 17β-HSD type 12 homologues. The MgHsd17b10 and MgHsd17b12 transcripts could be detected in all examined tissues with higher expression levels in digestive glands and gonad. After exposed to endocrine disrupting chemicals (Bisphenol A or 2,2',4,4'-tetrabromodiphenyl ether), the expression of MgHsd17b10 and MgHsd17b12 transcripts was both down-regulated in digestive glands. These findings suggest that MgHsd17b10 and MgHsd17b12 perhaps play an important role in the endocrine regulation of M. galloprovincialis.

  14. Osmotic Regulation of Betaine Content in Leymus chinensis Under Saline-alkali Stress and Cloning and Expression of Betaine Aldehyde Dehydrogenase(BADH)Gene

    Institute of Scientific and Technical Information of China (English)

    CUI Xi-yan; WANG Yong; GUO Ji-xun

    2008-01-01

    The potted Leymus chinensis seedlings were treated with saline-alkali solution of six different(from Ⅰ to Ⅵ) concentrations.The results demonstrate that the betaine content and Betaine-aldehyde dehydrogenase(BADH:EC 1.2.1.8) activities have a direct relation with increased stressing time in the same treatment;both exhibit a single peak with increasing the concentration of saline-alkali solution,and number V shows the highest value.The BADH gene of Leymus chinensis Was cloned by RT-PCR and RACE technology and Was designated as LcBADH.The cDNA sequence of LcBADH Was 1774bp including the open reading frame(ORF)of 1521bp(coding 506 amino acids).The vector of prokaryotic expression was constructed by inserting the LcBADH gene fragment into pET30a(+)and transformed into E. coli BL21(DE3).The result of SDS-PAGE shows that the idio-protein with a molecular mass of 56.78 kDa was effectively expressed in the recombinant bacteria induced by isopropyl β-D-thiogalactoside(IPTG).

  15. Cloning and Expression of S-mandelate Dehydrogenase Gene%S-扁桃酸脱氢酶基因的克隆及表达

    Institute of Scientific and Technical Information of China (English)

    曾贞; 杨军方; 杨成丽; 王鹏; 李大力

    2012-01-01

    S-mandelate dehydrogenase ( SMDH) can catalyze S-mandelic acid to benzoylformic acid. The SMDH nucleotide gene (mdlA) was cloned from DNA of Pseudomonas putida NUST by PCR, and the amplicon was inserted into prokaryotic expression vector pET-30a ( + ). This recombinant was transformed into E. Coli BL21 (DE3) and then highly expressed by induction of IPTG. The result of SDS-PAGE showed that the molecular weight of cloned SMDH was about 43kDa. The recombinant strain could catalyze S-mandelate to benzoylformic acid.%S-扁桃酸脱氢酶能够选择性催化S-扁桃酸生成苯甲酰甲酸.通过PCR扩增获得Pseudomonas putida NUST的S-扁桃酸脱氢酶全长基因(mdlA),并构建了表达载体pET30a(+)-mdlA,转化大肠杆菌E coli BL21 (DE3)后,经异丙基-β-D-硫代吡喃半乳糖苷(IPTG)诱导获得表达,SDS-PAGE结果显示表达蛋白为43kDa.所以工程菌细胞具有转化S-扁桃酸生成苯甲酰甲酸能力.

  16. Efficient expression of codon-adapted human acetaldehyde dehydrogenase 2 cDNA with 6×His tag in Pichia pastoris

    Institute of Scientific and Technical Information of China (English)

    ZHAO YuFeng; LEI MingKe; WU YuanXin; ZHANG ZiSheng; WANG CunWen

    2009-01-01

    Human mitochondrial acetaldehyde dehydrogenase 2 (ALDH2) catalyzes the oxidation of acetaldehyde to acetic acid. Therefore, ALDH2 has therapeutic potential in detoxification of acetaldehyde. Furthermore, ALDH2 catalyzes nitroglycerin to nitrate and 1, 2-glyceryldinitrate during therapy for angina pectoris, myocardial infarction, and heart failure. Large quantities of ALDH2 will be needed for potential clinical practice. In this study, Pichia pastoris was used as a platform for expression of human ALDH2.Based on the ALDH2~*1 cDNA sequence, we designed ALDH2 cDNA by choosing the P. pastoris preferred codons and by decreasing the G + C content level. The sequence was synthesized using the overlap extension PCR method. The cDNA and 6×His tags were subcloned into the plasmid pPIC9K.The recombinant protein was expressed in P. pastoris GS115 and purified using Ni~(2+)-Sepharose affinity chromatography. The amount of secreted protein in the culture was 80 mg/L in shake-flask cultivation and 260 mglL in high-density bioreactor fermentation. Secreted ALDH2 was easily purified from the culture supernatant by using Ni2+-Sepharose affinity chromatography. After purification of the fermentation supernatant, the enzyme had a specific activity of 1.2 U/mg protein. The yield was about 16 mg/L in a shake flask culture of P. pastoris GS115 which contained the original human ALDH2~*1 cDNA.

  17. Efficient expression of codon-adapted human acetaldehyde dehydrogenase 2 cDNA with 6×His tag in Pichia pastoris

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Human mitochondrial acetaldehyde dehydrogenase 2 (ALDH2) catalyzes the oxidation of acetaldehyde to acetic acid. Therefore, ALDH2 has therapeutic potential in detoxification of acetaldehyde. Further-more, ALDH2 catalyzes nitroglycerin to nitrate and 1, 2-glyceryldinitrate during therapy for angina pectoris, myocardial infarction, and heart failure. Large quantities of ALDH2 will be needed for potential clinical practice. In this study, Pichia pastoris was used as a platform for expression of human ALDH2. Based on the ALDH2*1 cDNA sequence, we designed ALDH2 cDNA by choosing the P. pastoris preferred codons and by decreasing the G + C content level. The sequence was synthesized using the overlap extension PCR method. The cDNA and 6×His tags were subcloned into the plasmid pPIC9K. The recombinant protein was expressed in P. pastoris GS115 and purified using Ni2+-Sepharose affinity chromatography. The amount of secreted protein in the culture was 80 mg/L in shake-flask cultivation and 260 mg/L in high-density bioreactor fermentation. Secreted ALDH2 was easily purified from the culture supernatant by using Ni2+-Sepharose affinity chromatography. After purification of the fermentation supernatant, the enzyme had a specific activity of 1.2 U/mg protein. The yield was about 16 mg/L in a shake flask culture of P. pastoris GS115 which contained the original human ALDH2*1 cDNA.

  18. Folic acid supplementation during pregnancy induces sex-specific changes in methylation and expression of placental 11β-hydroxysteroid dehydrogenase 2 in rats.

    Science.gov (United States)

    Penailillo, Reyna; Guajardo, Angelica; Llanos, Miguel; Hirsch, Sandra; Ronco, Ana Maria

    2015-01-01

    In the placenta, 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2) limits fetal glucocorticoid exposure and its inhibition has been associated to low birth weight. Its expression, encoded by the HSD11B2 gene is regulated by DNA methylation. We hypothesized that maternal diets supplemented with folic acid (FA) during pregnancy modify the expression of placental HSD11B2 through gene methylation. Wistar rats were fed with high (8 mg/kg) or normal low (1mg/kg, control) levels of FA during pregnancy. Concentrations of mRNA and protein in placentas were determined by qRT-PCR and Western blot respectively. Methylation in five CpG sites of the placental HSD11B2 promoter (-378 to -275) was analyzed by bacterial cloning and subsequent sequencing. In the FA-supplemented group, mRNA and protein levels of 11β-HSD2 decreased by 58% and increased by 89%, respectively, only in placentas attached to males. In controls, most CpG sites were not methylated except for the CpG2 site which was 80% methylated. CpG2 methylation level increased under the FA treatment; however, only in placentas attached to females was this increase significant (113%). This change was not related to HSD11B2 expression. Fetal weight of females from FA- supplemented mothers was 6% higher than females from control mothers. In conclusion, this is the first study reporting that FA over supplementation during pregnancy modifies the placental HSD11B2 gene expression and methylation in a sex-dependent manner, suggesting that maternal diets with high content of FA can induce early sex-specific responses, which may lead to long-term consequences for the offspring.

  19. Folic acid supplementation during pregnancy induces sex-specific changes in methylation and expression of placental 11β-hydroxysteroid dehydrogenase 2 in rats.

    Directory of Open Access Journals (Sweden)

    Reyna Penailillo

    Full Text Available In the placenta, 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2 limits fetal glucocorticoid exposure and its inhibition has been associated to low birth weight. Its expression, encoded by the HSD11B2 gene is regulated by DNA methylation. We hypothesized that maternal diets supplemented with folic acid (FA during pregnancy modify the expression of placental HSD11B2 through gene methylation. Wistar rats were fed with high (8 mg/kg or normal low (1mg/kg, control levels of FA during pregnancy. Concentrations of mRNA and protein in placentas were determined by qRT-PCR and Western blot respectively. Methylation in five CpG sites of the placental HSD11B2 promoter (-378 to -275 was analyzed by bacterial cloning and subsequent sequencing. In the FA-supplemented group, mRNA and protein levels of 11β-HSD2 decreased by 58% and increased by 89%, respectively, only in placentas attached to males. In controls, most CpG sites were not methylated except for the CpG2 site which was 80% methylated. CpG2 methylation level increased under the FA treatment; however, only in placentas attached to females was this increase significant (113%. This change was not related to HSD11B2 expression. Fetal weight of females from FA- supplemented mothers was 6% higher than females from control mothers. In conclusion, this is the first study reporting that FA over supplementation during pregnancy modifies the placental HSD11B2 gene expression and methylation in a sex-dependent manner, suggesting that maternal diets with high content of FA can induce early sex-specific responses, which may lead to long-term consequences for the offspring.

  20. Insulin, CCAAT/Enhancer-Binding Proteins and Lactate Regulate the Human 11β-Hydroxysteroid Dehydrogenase Type 2 Gene Expression in Colon Cancer Cell Lines

    Science.gov (United States)

    Alikhani-Koupaei, Rasoul; Ignatova, Irena D.; Guettinger, Andreas; Frey, Felix J.; Frey, Brigitte M.

    2014-01-01

    11β-Hydroxysteroid dehydrogenases (11beta-HSD) modulate mineralocorticoid receptor transactivation by glucocorticoids and regulate access to the glucocorticoid receptor. The isozyme 11beta-HSD2 is selectively expressed in mineralocorticoid target tissues and its activity is reduced in various disease states with abnormal sodium retention and hypertension, including the apparent mineralocorticoid excess. As 50% of patients with essential hypertension are insulin resistant and hyperinsulinemic, we hypothesized that insulin downregulates the 11beta-HSD2 activity. In the present study we show that insulin reduced the 11beta-HSD2 activity in cancer colon cell lines (HCT116, SW620 and HT-29) at the transcriptional level, in a time and dose dependent manner. The downregulation was reversible and required new protein synthesis. Pathway analysis using mRNA profiling revealed that insulin treatment modified the expression of the transcription factor family C/EBPs (CCAAT/enhancer-binding proteins) but also of glycolysis related enzymes. Western blot and real time PCR confirmed an upregulation of C/EBP beta isoforms (LAP and LIP) with a more pronounced increase in the inhibitory isoform LIP. EMSA and reporter gene assays demonstrated the role of C/EBP beta isoforms in HSD11B2 gene expression regulation. In addition, secretion of lactate, a byproduct of glycolysis, was shown to mediate insulin-dependent HSD11B2 downregulation. In summary, we demonstrate that insulin downregulates HSD11B2 through increased LIP expression and augmented lactate secretion. Such mechanisms are of interest and potential significance for sodium reabsorption in the colon. PMID:25133511

  1. Insulin, CCAAT/enhancer-binding proteins and lactate regulate the human 11β-hydroxysteroid dehydrogenase type 2 gene expression in colon cancer cell lines.

    Directory of Open Access Journals (Sweden)

    Thomas Andrieu

    Full Text Available 11β-Hydroxysteroid dehydrogenases (11beta-HSD modulate mineralocorticoid receptor transactivation by glucocorticoids and regulate access to the glucocorticoid receptor. The isozyme 11beta-HSD2 is selectively expressed in mineralocorticoid target tissues and its activity is reduced in various disease states with abnormal sodium retention and hypertension, including the apparent mineralocorticoid excess. As 50% of patients with essential hypertension are insulin resistant and hyperinsulinemic, we hypothesized that insulin downregulates the 11beta-HSD2 activity. In the present study we show that insulin reduced the 11beta-HSD2 activity in cancer colon cell lines (HCT116, SW620 and HT-29 at the transcriptional level, in a time and dose dependent manner. The downregulation was reversible and required new protein synthesis. Pathway analysis using mRNA profiling revealed that insulin treatment modified the expression of the transcription factor family C/EBPs (CCAAT/enhancer-binding proteins but also of glycolysis related enzymes. Western blot and real time PCR confirmed an upregulation of C/EBP beta isoforms (LAP and LIP with a more pronounced increase in the inhibitory isoform LIP. EMSA and reporter gene assays demonstrated the role of C/EBP beta isoforms in HSD11B2 gene expression regulation. In addition, secretion of lactate, a byproduct of glycolysis, was shown to mediate insulin-dependent HSD11B2 downregulation. In summary, we demonstrate that insulin downregulates HSD11B2 through increased LIP expression and augmented lactate secretion. Such mechanisms are of interest and potential significance for sodium reabsorption in the colon.

  2. Glucose-6-phosphate dehydrogenase

    Science.gov (United States)

    ... medlineplus.gov/ency/article/003671.htm Glucose-6-phosphate dehydrogenase test To use the sharing features on this page, please enable JavaScript. Glucose-6-phosphate dehydrogenase (G6PD) is a protein that helps red ...

  3. The Role of Sugar-related Regulation in the Light-dependent Alterations of Arabidopsis Glutamate Dehydrogenase Genes Expression

    Directory of Open Access Journals (Sweden)

    E.Yu. Garnik

    2014-12-01

    Full Text Available Expression of gdh1 and gdh2 genes of Arabidopsis thaliana increases in the dark and decreases in the light. The reason of such alteration seems to be a glucose rising in photosynthetic cell in the light, but this hypothesis needs to be confirmed. In this work we investigate the role of glucose and hexokinase 1 in the light-dependent regulation of the gdh1 and gdh2 expression. A comparison of expression profiles of apl3, gdh1, gdh2 genes in presenсe of exogenous sucrose in the dark and in the light has demonstrated that sugar-related repression of gdh1 and gdh2 genes is insufficient to provide the high decrease of their transcripts in the light. Using Arabidopsis mutant gin2-1 with a defect in hxk1 gene we demonstrated that such a decrease is not depended on the regulatory function of hexokinase 1. We presume that light- dependent alterations of gdh1 and gdh2 expression are mediated by some chloroplast-to-nucleus regulatory signals.

  4. Stem cell marker aldehyde dehydrogenase 1 (ALDH1)-expressing cells are enriched in triple-negative breast cancer.

    Science.gov (United States)

    Li, Huihui; Ma, Fei; Wang, Haijuan; Lin, Chen; Fan, Ying; Zhang, Xueyan; Qian, Haili; Xu, Binghe

    2013-12-17

    The stem cell marker ALDH1 has been of particular interest to scientists since it has been successfully used as a marker to isolate cancer stem cells from breast cancers. However, little is known, especially in Chinese breast cancer patients, on whether ALDH1 enrichment is prevalent in certain subtypes of breast cancer. In this study, we performed flow cytometry and immunohistochemistry to measure the expression of ALDH1 in 10 breast cancer cell lines and in a set of tissue microarrays consisting of 101 breast cancer tissues from the Chinese population. The 101 breast cancer tissues included 4 cancer subtypes defined on bases of their ER, PR, and HER2 statuses: triple-negative (25 cases), luminal A (33 cases), luminal B (16 cases) and HER2-overexpressing (HER2-OE, 27 cases). We found that ALDH1 was expressed in 25 of the 101 cases of breast cancer tissues. When the analysis was stratified, we found that the expression of ALDH1 varied significantly among the 4 subtypes, with a higher expression in triple-negative breast cancer (TNBC, p=0.003) than in the other 3 subtypes. In a series of breast cancer cell lines, we also confirmed that ALDH1 activity was mainly found in TNBC cell lines compared with non-TNBC ones (15.6% ± 2.45% vs 5.5% ± 2.58%, p=0.026). These data support the concept that the expression of ALDH1 is higher in TNBC than non-TNBC, which may be clinically meaningful for a better understanding of the poor prognosis of TNBC patients.

  5. Glutamate dehydrogenase and Na+-K+ ATPase expression and growth response of Litopenaeus vannamei to different salinities and dietary protein levels

    Institute of Scientific and Technical Information of China (English)

    LI Erchao; Leticia ARENA; Gabriel LIZAMA; Gabriela GAXIOLA; Gerard CUZON; Carlos ROSAS; CHEN Liqiao; Alain VAN WORMHOUD

    2011-01-01

    Improvement in the osmoregulation capacity via nutritional supplies is vitally important in shrimp aquaculture. The effects of dietary protein levels on the osmoregulation capacity of the Pacific white shrimp (L. vannamei) were investigated. This involved an examination of growth performance, glutamate dehydrogenase (GDH) and Na+-K+ ATPase mRNA expression,, and GDH activity in muscles and gills. Three experimental diets were formulated, containing 25%, 40~/5, and 50% dietary protein, and fed to the shrimp at a salinity of 25. After 20 days, no significant difference was observed in weight gain, though GDH and Na+-K+ ATPase gene expression and GDH activity increased with higher dietary protein levels. Subsequently, shrimp fed diets with 25% and 50% dietary protein were transferred into tanks with salinities of 38 and 5, respectively, and sampled at weeks 1and 2. Shrimp fed with 40% protein at 25 in salinity (optimal conditions) were used as a control.Regardless of the salinities, shrimp fed with 50% dietary protein had significantly higher growth performance than other diets; no significant differences were found in comparison with the control.Shrimp fed with 25% dietary protein and maintained at salinities of 38 and 5 had significantly lower weight gain values after 2 weeks. Ambient salinity change also stimulated the hepatosomatic index,which increased in the first week and then recovered to a relatively normal level, as in the control,after 2 weeks. These findings indicate that in white shrimp, the specific protein nutrient and energy demands related to ambient salinity change are associated with protein metabolism. Increased dietary protein level could improve the osmoregnlation capacity of L. vannamei with more energy resources allocated to GDH activity and expression.

  6. Glutamate dehydrogenase and Na+-K+ ATPase expression and growth response of Litopenaeus vannamei to different salinities and dietary protein levels

    Science.gov (United States)

    Li, Erchao; Arena, Leticia; Lizama, Gabriel; Gaxiola, Gabriela; Cuzon, Gerard; Rosas, Carlos; Chen, Liqiao; van Wormhoudt, Alain

    2011-03-01

    Improvement in the osmoregulation capacity via nutritional supplies is vitally important in shrimp aquaculture. The effects of dietary protein levels on the osmoregulation capacity of the Pacific white shrimp ( L. vannamei) were investigated. This involved an examination of growth performance, glutamate dehydrogenase (GDH) and Na+-K+ ATPase mRNA expression,, and GDH activity in muscles and gills. Three experimental diets were formulated, containing 25%, 40%, and 50% dietary protein, and fed to the shrimp at a salinity of 25. After 20 days, no significant difference was observed in weight gain, though GDH and Na+-K+ ATPase gene expression and GDH activity increased with higher dietary protein levels. Subsequently, shrimp fed diets with 25% and 50% dietary protein were transferred into tanks with salinities of 38 and 5, respectively, and sampled at weeks 1 and 2. Shrimp fed with 40% protein at 25 in salinity (optimal conditions) were used as a control. Regardless of the salinities, shrimp fed with 50% dietary protein had significantly higher growth performance than other diets; no significant differences were found in comparison with the control. Shrimp fed with 25% dietary protein and maintained at salinities of 38 and 5 had significantly lower weight gain values after 2 weeks. Ambient salinity change also stimulated the hepatosomatic index, which increased in the first week and then recovered to a relatively normal level, as in the control, after 2 weeks. These findings indicate that in white shrimp, the specific protein nutrient and energy demands related to ambient salinity change are associated with protein metabolism. Increased dietary protein level could improve the osmoregulation capacity of L. vannamei with more energy resources allocated to GDH activity and expression.

  7. Cloning, expression and protective immunity evaluation of the full-length cDNA encoding succinate dehydrogenase iron-sulfur protein of Schistosoma japonicum

    Institute of Scientific and Technical Information of China (English)

    YU JunLong; WANG ShiPing; LI WenKai; DAI Gan; XU ShaoRui; HE Zhuo; PENG XianChu; ZHOU SongHua; LIU XueQin

    2007-01-01

    1071-bp fragment was obtained from the Schistosoma japonicum (Chinese strain) adult cDNA library after the 3' and 5' ends of the incomplete expression sequence tag (EST) of succinate dehydrogenase iron-sulfur protein of Schistosoma japonicum (SjSDISP) were amplified by the anchored PCR with 2pairs of primers designed according to the EST of SjSDISP and the sequence of multiclone sites of the library vector. Sequence analysis indicated that the fragment was a full-length cDNA with a complete open reading frame (ORF), encoding 278 amino acid residues. The fragment was cloned into prokaryotic expression vector pQE30, and subsequently sequenced and expressed in Escherichia coll.SDS-PAGE and Western-blot analyses showed that the recombinant protein was about 32 kD and could be recognized by the polyclonal antisera from rabbits immunized with Schistosoma japonicum adult worm antigen. Compared with the FCA controls, mice vaccinated with rSjSDISP (test) or rSjGST (positive control) all revealed high levels of specific antibody and significant reduction in worm burden, liver eggs per gram (LEPG), fecal eggs per gram (FEPG) and intrauterine eggs. These results suggest that SjSDISP may be a novel and partially protective vaccine candidate against schistosomiasis. In contrast to the worm burden reduction rate, the higher degree of egg reduction rate in the test group also suggested that SjSDISP vaccine may primarily play a role in anti-embryonation or anti-fecundity immunity.

  8. Cloning, expression and protective immunity evalua- tion of the full-length cDNA encoding succinate dehydrogenase iron-sulfur protein of Schistosoma japonicum

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    1071-bp fragment was obtained from the Schistosoma japonicum (Chinese strain) adult cDNA library after the 3′ and 5′ ends of the incomplete expression sequence tag (EST) of succinate dehydrogenase iron-sulfur protein of Schistosoma japonicum (SjSDISP) were amplified by the anchored PCR with 2 pairs of primers designed according to the EST of SjSDISP and the sequence of multiclone sites of the library vector. Sequence analysis indicated that the fragment was a full-length cDNA with a complete open reading frame (ORF), encoding 278 amino acid residues. The fragment was cloned into prokary- otic expression vector pQE30, and subsequently sequenced and expressed in Escherichia coli. SDS-PAGE and Western-blot analyses showed that the recombinant protein was about 32 kD and could be recognized by the polyclonal antisera from rabbits immunized with Schistosoma japonicum adult worm antigen. Compared with the FCA controls, mice vaccinated with rSjSDISP (test) or rSjGST (posi- tive control) all revealed high levels of specific antibody and significant reduction in worm burden, liver eggs per gram (LEPG), fecal eggs per gram (FEPG) and intrauterine eggs. These results suggest that SjSDISP may be a novel and partially protective vaccine candidate against schistosomiasis. In contrast to the worm burden reduction rate, the higher degree of egg reduction rate in the test group also sug- gested that SjSDISP vaccine may primarily play a role in anti-embryonation or anti-fecundity immunity.

  9. Expression of wild-type and mutant medium-chain acyl-CoA dehydrogenase (MCAD) cDNA in eucaryotic cells

    DEFF Research Database (Denmark)

    Jensen, T G; Andresen, B S; Bross, P;

    1992-01-01

    An effective EBV-based expression system for eucaryotic cells has been developed and used for the study of the mitochondrial enzyme medium-chain acyl-CoA dehydrogenase (MCAD). 1325 bp of PCR-generated MCAD cDNA, containing the entire coding region, was placed between the SV40 early promoter...... and polyadenylation signals in the EBV-based vector. Both wild-type MCAD cDNA and cDNA containing the prevalent disease-causing mutation A to G at position 985 of the MCAD cDNA were tested. In transfected COS-7 cells, the steady state amount of mutant MCAD protein was consistently lower than the amount of wild......-type human enzyme. The enzyme activity in extracts from cells harbouring the wild-type MCAD cDNA was dramatically higher than in the controls (harbouring the vector without the MCAD gene) while only a slightly higher activity was measured with the mutant MCAD. The mutant MCAD present behaves like wild...

  10. Cloning, expression, and biochemical characterization of a novel NADP(+)-dependent 7α-hydroxysteroid dehydrogenase from Clostridium difficile and its application for the oxidation of bile acids.

    Science.gov (United States)

    Bakonyi, Daniel; Hummel, Werner

    2017-04-01

    A gene encoding a novel 7α-specific NADP(+)-dependent hydroxysteroid dehydrogenase from Clostridium difficile was cloned and heterologously expressed in Escherichia coli. The enzyme was purified using an N-terminal hexa-his-tag and biochemically characterized. The optimum temperature is at 60°C, but the enzyme is inactivated at this temperature with a half-life time of 5min. Contrary to other known 7α-HSDHs, for example from Clostridium sardiniense or E. coli, the enzyme from C. difficile does not display a substrate inhibition. In order to demonstrate the applicability of this enzyme, a small-scale biotransformation of the bile acid chenodeoxycholic acid (CDCA) into 7-ketolithocholic acid (7-KLCA) was carried out with simultaneous regeneration of NADP(+) using an NADPH oxidase that resulted in a complete conversion (<99%). Furthermore, by a structure-based site-directed mutagenesis, cofactor specificity of the 7α-HSDH from Clostridium difficile was altered to accept NAD(H). This mutant was biochemically characterized and compared to the wild-type.

  11. Effect of ginger root on cyclooxygenase-1 and 15-hydroxyprostaglandin dehydrogenase expression in colonic mucosa of humans at normal and increased risk for colorectal cancer.

    Science.gov (United States)

    Jiang, Yan; Turgeon, Danielle K; Wright, Benjamin D; Sidahmed, Elkhansa; Ruffin, Mack T; Brenner, Dean E; Sen, Ananda; Zick, Suzanna M

    2013-09-01

    Elevated tissue levels of prostaglandin E2, produced by cyclooxygenase (COX), are an early event in colorectal cancer (CRC). Data suggest the efficacy of nonsteroidal anti-inflammatory drugs, such as cancer preventives, in the inhibition of COX activity; however, side effects of nonsteroidal anti-inflammatory pose unacceptable limitations. Ginger has been reported to have anti-inflammatory activities with significant CRC preventive potential. We investigated whether consumption of 2.0 g ginger daily regulated the level of two key enzymes that control prostaglandin E2 production, COX-1 and NAD(+)-dependent 15-hydroxyprostaglandin dehydrogenase (15-PGDH). Thirty participants at normal and 20 participants at increased risk for CRC were randomized and given 2.0 g/day ginger or placebo for 28 days. Flexible sigmoidoscopy was used to obtain colon biopsies at baseline and the end of the study. Tissue levels of COX-1 and 15-PGDH were assessed using western blotting. After ginger consumption, participants at increased risk for CRC had a significantly reduced colonic COX-1 protein level (23.8±41%) compared with the placebo group (18.9±52%; P=0.03). Protein levels of 15-PGDH in the colon were unchanged. In participants who were at normal risk for CRC, neither protein levels of COX-1 nor 15-PGDH in the colon were altered by ginger consumption. Ginger significantly lowered COX-1 protein expression in participants at increased risk for CRC but not in those at normal risk for CRC. Ginger did not alter 15-PGDH protein expression in either increased or normal-risk participants. Further investigation, in larger studies with a longer ginger intervention, is needed to examine the ability of ginger to impact tissue levels of prostaglandin.

  12. Improved NADPH Regeneration for Fungal Cytochrome P450 Monooxygenase by Co-Expressing Bacterial Glucose Dehydrogenase in Resting-Cell Biotransformation of Recombinant Yeast.

    Science.gov (United States)

    Jeon, Hyunwoo; Durairaj, Pradeepraj; Lee, Dowoo; Ahsan, Md Murshidul; Yun, Hyungdon

    2016-12-28

    Fungal cytochrome P450 (CYP) enzymes catalyze versatile monooxygenase reactions and play a major role in fungal adaptations owing to their essential roles in the production avoid metabolites critical for pathogenesis, detoxification of xenobiotics, and exploitation avoid substrates. Although fungal CYP-dependent biotransformation for the selective oxidation avoid organic compounds in yeast system is advantageous, it often suffers from a shortage avoid intracellular NADPH. In this study, we aimed to investigate the use of bacterial glucose dehydrogenase (GDH) for the intracellular electron regeneration of fungal CYP monooxygenase in a yeast reconstituted system. The benzoate hydroxylase FoCYP53A19 and its homologous redox partner FoCPR from Fusarium oxysporum were co-expressed with the BsGDH from Bacillus subtilis in Saccharomyces cerevisiae for heterologous expression and biotransformations. We attempted to optimize several bottlenecks concerning the efficiency of fungal CYP-mediated whole-cell-biotransformation to enhance the conversion. The catalytic performance of the intracellular NADPH regeneration system facilitated the hydroxylation of benzoic acid to 4-hydroxybenzoic acid with high conversion in the resting-cell reaction. The FoCYP53A19+FoCPR+BsGDH reconstituted system produced 0.47 mM 4-hydroxybenzoic acid (94% conversion) in the resting-cell biotransformations performed in 50 mM phosphate buffer (pH 6.0) containing 0.5 mM benzoic acid and 0.25% glucose for 24 h at 30°C. The "coupled-enzyme" system can certainly improve the overall performance of NADPH-dependent whole-cell biotransformations in a yeast system.

  13. Ovarian expression of inhibin-subunits, 3β-hydroxysteroid dehydrogenase, and cytochrome P450 aromatase during the estrous cycle and pregnancy of shiba goats (Capra hircus).

    Science.gov (United States)

    Kandiel, Mohamed M M; Watanabe, Gen; Taya, Kazuyoshi

    2010-01-01

    The cellular localization of the inhibin subunits (α, β(A), and β (B)), steroidogenic enzymes (3β-hydroxysteroid dehydrogenase (3βHSD) and cytochrome P450 aromatase (P450arom) were evaluated in the ovaries of cyclic (n=6) and pregnant (n=2) Shiba goats (Capra Hircus). The immunointensity of inhibin α and β(A) subunits showed an increase in the granulosa cells (GC) of developing follicles. Inhibin β(B) subunit and P450arom showed high expression in GC of antral follicles. 3βHSD immunoreactivity was uniform in preantral and antral follicles. In follicular phase and late pregnancy, there was a strong expression of inhibin α subunit in GC of antral follicles. Although in mid pregnancy, antral follicles GC showed moderate immunostaining of inhibin β subunits, the immunoreactivity of inhibin β(A) and β(B) subunits was high during the follicular and luteal stages, respectively. While, immunoreactivity of GC to P450arom was moderate during all studied stages, and 3βHSD immunoreactivity was plentiful in antral follicles during the luteal phase. The immunoreactivity to inhibin α subunit and P450arom was abundant during mid pregnancy in the luteal tissues. Immunoreaction to inhibin β subunits was faint-to-moderate in cyclic and pregnancy corpora lutea. Immunoexpression of 3βHSD was maximal in late pregnancy corpora lutea. The present results suggest that, in goats, the GC of antral follicles are the main source of dimeric inhibins and that corpora lutea may partially participate in the secretion of inhibin. Changes in ovarian hormonal levels might depend on the synthesizing capacity of hormones in the follicles and corpora lutea to regulate the goat's reproductive stages.

  14. 11beta-hydroxysteroid dehydrogenase type 2 expression in the newly formed Leydig cells after ethane dimethanesulphonate treatment of adult rats.

    Directory of Open Access Journals (Sweden)

    Katerina Georgieva

    2008-01-01

    Full Text Available The enzyme 11beta-hydroxysteroid dehydrogenase (11beta-HSD catalyzes the reversible conversion of physiologically active corticosterone to the biologically inert 11beta-dehydrocorticosterone in rat testis and protect the Leydig cells (LCs against the suppressive effect of glucocorticoids. The developmental pathway of the adult LCs population is accompanied with an increase in the 11beta-HDS activity. Thus, 11beta-HDS together with its role in controlling the toxicological effect of glucocorticoids on LCs can be used as a marker for their functional maturity. Ethane 1,2-dimethanesulphonate (EDS treatment of adult rats become unique appropriate model, which enable to answer many questions related to the differentiation of adult LCs in the prepubertal rat testis. The aim of the present study was to investigate the specific changes in the 11beta-HDS type 2 immunoreactivity in tandem with the expression of androgen receptor (AR during renewal of LCs population after EDS treatment. In the present study, we observed the first appearance of immunostaining for 11beta-HSD2 in new LCs population on day 14 after EDS administration when the progenitor LCs were detected. Our immunohistochemical analysis revealed progressive increases in the 11beta-HSD2 reaction intensity on 21 days after EDS treatment and reached a maximum on day 35. AR immunoexpression was found in new LCs on day 14 and 21 after EDS injection with an increasing curve of intensity. The most prominent AR immunostaining in new population LCs was evident by 35 days after EDS and that coincided with the increased number of LCs and restoration of adult LCs population. Our results demonstrated similar pattern of immunoreactivity for 11beta-HSD2 and AR in new LCs population after EDS treatment and suggested that the changes in 11beta-HSD2 expression can be used for evaluation of adult LCs differentiation in rat testis.

  15. [The expression of the sperm-specific lactate dehydrogenase gene Ldh-c in plateau pika (Ochotona curzoniae) cardiac muscle and its effect on the anaerobic glycolysis].

    Science.gov (United States)

    Li, Xiao; Wei, Lian; Wang, Yang; Xu, Li-Na; Wei, Lin-Na; Wei, Deng-Bang

    2015-06-25

    The plateau pika (Ochotona curzoniae) has a strong adaptability to hypoxic plateau environment. We found that the sperm-specific lactate dehydrogenase (LDH-C4) gene Ldh-c expressed in plateau pika cardiac muscle. In order to shed light on the effect of LDH-C4 on the anaerobic glycolysis in plateau pika cardiac muscle, 20 pikas were randomly divided into the inhibitor group and the control group, and the sample size of each group was 10. The pikas of inhibitor group were injected with 1 mL 1 mol/L N-isopropyl oxamate, a specific LDH-C4 inhibitor, in biceps femoris muscle of hind legs, each leg with 500 μL. The pikas of control group were injected with the same volume of normal saline (0.9% NaCl). The mRNA and protein expression levels of Ldh-c gene in plateau pika cardiac muscle were determined by real-time PCR and Western blot. The activities of LDH, and the contents of lactate (LD) and ATP in cardiac muscle were compared between the inhibitor group and the control group. The results showed that 1) the expression levels of Ldh-c mRNA and protein were 0.47 ± 0.06 and 0.68 ± 0.08, respectively; 2) 30 min after injection of 1 mL 1 mol/L N-isopropyl oxamate in biceps femoris muscle, the concentration of N-isopropyl oxamate in blood was 0.08 mmol/L; 3) in cardiac muscle of the inhibitor group and the control group, the LDH activities were (6.18 ± 0.48) U/mg and (9.08 ± 0.58) U/mg, the contents of LD were (0.21 ± 0.03) mmol/g and (0.26 ± 0.04) mmol/g, and the contents of ATP were (4.40 ± 0.69) nmol/mg and (6.18 ± 0.73) nmol/mg (P < 0.01); 5) the inhibition rates of N-isopropyl oxamate to LDH, LD and ATP were 31.98%, 20.90% and 28.70%, respectively. The results suggest that Ldh-c expresses in cardiac muscle of plateau pika, and the pika cardiac muscle may get at least 28% ATP for its activities by LDH-C4 catalyzed anaerobic glycolysis, which reduces the dependence on oxygen and enhances the adaptation to the hypoxic environments.

  16. Caffeine reduces 11β-hydroxysteroid dehydrogenase type 2 expression in human trophoblast cells through the adenosine A(2B receptor.

    Directory of Open Access Journals (Sweden)

    Saina Sharmin

    Full Text Available Maternal caffeine consumption is associated with reduced fetal growth, but the underlying molecular mechanisms are unknown. Since there is evidence that decreased placental 11β-hydroxysteroid dehydrogenase type 2 (11β-HSD2 is linked to fetal growth restriction, we hypothesized that caffeine may inhibit fetal growth partly through down regulating placental 11β-HSD2. As a first step in examining this hypothesis, we studied the effects of caffeine on placental 11β-HSD2 activity and expression using our established primary human trophoblast cells as an in vitro model system. Given that maternal serum concentrations of paraxanthine (the primary metabolite of caffeine were greater in women who gave birth to small-for-gestational age infants than to appropriately grown infants, we also studied the effects of paraxanthine. Our main findings were: (1 both caffeine and paraxanthine decreased placental 11β-HSD2 activity, protein and mRNA in a concentration-dependent manner; (2 this inhibitory effect was mediated by the adenosine A(2B receptor, since siRNA-mediated knockdown of this receptor prevented caffeine- and paraxanthine-induced inhibition of placental 11β-HSD2; and (3 forskolin (an activator of adenyl cyclase and a known stimulator of 11β-HSD2 abrogated the inhibitory effects of both caffeine and paraxanthine, which provides evidence for a functional link between exposure to caffeine and paraxanthine, decreased intracellular levels of cAMP and reduced placental 11β-HSD2. Taken together, these findings reveal that placental 11β-HSD2 is a novel molecular target through which caffeine may adversely affect fetal growth. They also uncover a previously unappreciated role for the adenosine A(2B receptor signaling in regulating placental 11β-HSD2, and consequently fetal development.

  17. Host cell and expression engineering for development of an E. coli ketoreductase catalyst: Enhancement of formate dehydrogenase activity for regeneration of NADH

    Directory of Open Access Journals (Sweden)

    Mädje Katharina

    2012-01-01

    Full Text Available Abstract Background Enzymatic NADH or NADPH-dependent reduction is a widely applied approach for the synthesis of optically active organic compounds. The overall biocatalytic conversion usually involves in situ regeneration of the expensive NAD(PH. Oxidation of formate to carbon dioxide, catalyzed by formate dehydrogenase (EC 1.2.1.2; FDH, presents an almost ideal process solution for coenzyme regeneration that has been well established for NADH. Because isolated FDH is relatively unstable under a range of process conditions, whole cells often constitute the preferred form of the biocatalyst, combining the advantage of enzyme protection in the cellular environment with ease of enzyme production. However, the most prominent FDH used in biotransformations, the enzyme from the yeast Candida boidinii, is usually expressed in limiting amounts of activity in the prime host for whole cell biocatalysis, Escherichia coli. We therefore performed expression engineering with the aim of enhancing FDH activity in an E. coli ketoreductase catalyst. The benefit resulting from improved NADH regeneration capacity is demonstrated in two transformations of technological relevance: xylose conversion into xylitol, and synthesis of (S-1-(2-chlorophenylethanol from o-chloroacetophenone. Results As compared to individual expression of C. boidinii FDH in E. coli BL21 (DE3 that gave an intracellular enzyme activity of 400 units/gCDW, co-expression of the FDH with the ketoreductase (Candida tenuis xylose reductase; XR resulted in a substantial decline in FDH activity. The remaining FDH activity of only 85 U/gCDW was strongly limiting the overall catalytic activity of the whole cell system. Combined effects from increase in FDH gene copy number, supply of rare tRNAs in a Rosetta strain of E. coli, dampened expression of the ketoreductase, and induction at low temperature (18°C brought up the FDH activity threefold to a level of 250 U/gCDW while reducing the XR activity by

  18. Proliferative responses to altered 17beta-hydroxysteroid dehydrogenase (17HSD) type 2 expression in human breast cancer cells are dependent on endogenous expression of 17HSD type 1 and the oestradiol receptors.

    Science.gov (United States)

    Jansson, A; Gunnarsson, C; Stål, O

    2006-09-01

    The primary source of oestrogen in premenopausal women is the ovary but, after menopause, oestrogen biosynthesis in peripheral tissue is the exclusive site of formation. An enzyme group that affects the availability of active oestrogens is the 17beta-hydroxysteroid dehydrogenase (17HSD) family. In breast cancer, 17HSD type 1 and type 2 have been mostly investigated and seem to be the principal 17HSD enzymes involved thus far. The question whether 17HSD type 1 or type 2 is of greatest importance in breast tumour development is still not clear. The aim of this study was to investigate how the loss of 17HSD type 2 expression, using siRNA in the non-tumour breast epithelial cells HMEC (human mammal epithelial cells) and MCF10A, and gain of 17HSD type 2 expression, using transient transfection in the breast cancer derived cell lines MCF7 and T47D, affect oestradiol conversion and proliferation rate measured as S-phase fraction. We further investigated how this was related to the endogenous expression of 17HSD type 1 and oestradiol receptors in the examined cell lines. The oestradiol level in the medium changed significantly in the MCF7 transfected cells and the siRNA-treated HMEC cells, but not in T47D or MCF10A. The S-phase fraction decreased in the 17HSD type 2-transfected MCF7 cells and the siRNA-treated HMEC cells. The results seemed to be dependent on the endogenous expression of 17HSD type 1 and the oestradiol receptors. In conclusion, we found that high or low levels of 17HSD type 2 affected the oestradiol concentration significantly. However, the response was dependent on the endogenous expression of 17HSD type 1. Expression of 17HSD type 1 seems to be dominant to 17HSD type 2. Therefore, it may be important to investigate a ratio between 17HSD type 1 and 17HSD type 2.

  19. Tumor necrosis factor-alpha upregulates 11beta-hydroxysteroid dehydrogenase type 1 expression by CCAAT/enhancer binding protein-beta in HepG2 cells.

    Science.gov (United States)

    Ignatova, Irena D; Kostadinova, Radina M; Goldring, Christopher E; Nawrocki, Andrea R; Frey, Felix J; Frey, Brigitte M

    2009-02-01

    The enzyme 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) catalyzes the conversion of inactive to active glucocorticoids. 11beta-HSD1 plays a crucial role in the pathogenesis of obesity and controls glucocorticoid actions in inflammation. Several studies have demonstrated that TNF-alpha increases 11beta-HSD1 mRNA and activity in various cell models. Here, we demonstrate that mRNA and activity of 11beta-HSD1 is increased in liver tissue from transgenic mice overexpressing TNF-alpha, indicating that this effect also occurs in vivo. To dissect the molecular mechanism of this increase, we investigated basal and TNF-alpha-induced transcription of the 11beta-HSD1 gene (HSD11B1) in HepG2 cells. We found that TNF-alpha acts via p38 MAPK pathway. Transient transfections with variable lengths of human HSD11B1 promoter revealed highest activity with or without TNF-alpha in the proximal promoter region (-180 to +74). Cotransfection with human CCAAT/enhancer binding protein-alpha (C/EBPalpha) and C/EBPbeta-LAP expression vectors activated the HSD11B1 promoter with the strongest effect within the same region. Gel shift and RNA interference assays revealed the involvement of mainly C/EBPalpha, but also C/EBPbeta, in basal and only of C/EBPbeta in the TNF-alpha-induced HSD11B1 expression. Chromatin immunoprecipitation assay confirmed in vivo the increased abundance of C/EBPbeta on the proximal HSD11B1 promoter upon TNF-alpha treatment. In conclusion, C/EBPalpha and C/EBPbeta control basal transcription, and TNF-alpha upregulates 11beta-HSD1, most likely by p38 MAPK-mediated increased binding of C/EBPbeta to the human HSD11B1 promoter. To our knowledge, this is the first study showing involvement of p38 MAPK in the TNF-alpha-mediated 11beta-HSD1 regulation, and that TNF-alpha stimulates enzyme activity in vivo.

  20. Expression of ghrelin and the ghrelin receptor in different stages of porcine corpus luteum development and the inhibitory effects of ghrelin on progesterone secretion, 3β-hydroxysteroid dehydrogenase (3β-honestly significant difference (HSD)) activity and protein expression.

    Science.gov (United States)

    Rak-Mardyła, A; Gregoraszczuk, E L; Karpeta, A; Duda, M

    2012-05-01

    Recent studies have suggested that ghrelin plays a direct role in controlling female reproduction. The aim of the present study was to investigate the mRNA and protein expression of ghrelin and its receptor (via real time PCR, Western blot and immunohistochemistry analysis, respectively) in porcine corpora lutea (CL) collected during early (CL1: 1-2 days after ovulation), middle (CL2: 7-10 after ovulation), and late luteal phase (CL3: 13-15 after ovulation). Ghrelin expression and concentration of both acylated and unacylated forms of ghrelin significantly increased during CL development. Immunohistochemistry analysis shown localization of ghrelin protein in the cytoplasm of large luteal cells. No changes in the expression of the ghrelin receptor were observed. Direct in vitro effects of ghrelin on progesterone (P4) secretion and 3-beta-hydroxysteroid dehydrogenase (3β-honestly significant difference (HSD)) activity, which were measured by the conversion of pregnenolone (P5) to P4, and 3β-HSD protein expression were then analyzed. To assess 3β-HSD activities, mature luteal cells were first cultured for 24 h with ghrelin at 100, 250, 500 and 1000 pg/mL with P5, or with aminoglutethimide (AMG). AMG is an inhibitor of CYP11A1-mediated hydroxylation; an addition of AMG and P5 enabled P4 production to serve as an index of 3β-HSD activity. Inhibitory effects of ghrelin on P4 secretion, 3β-HSD activity and protein expression were observed. In conclusion, the presence of ghrelin and its receptor in porcine corpora lutea and the direct inhibitory effects of ghrelin on luteal P4 secretion and 3β-HSD suggest potential auto/paracrine regulation by ghrelin in the luteal phase of ovary function.

  1. Expression of Retinaldehyde Dehydrogenase Enzymes in Mucosal Dendritic Cells and Gut-Draining Lymph Node Stromal Cells Is Controlled by Dietary Vitamin A

    NARCIS (Netherlands)

    R. Molenaar; M. van Knippenberg; G. Goverse; B.J. Olivier; A.F. de Vos; T. O'Toole; R.E. Mebius

    2011-01-01

    The vitamin A metabolite retinoic acid (RA) plays a crucial role in mucosal immune responses. We demonstrate in this study that RA-producing retinaldehyde dehydrogenase (RALDH) enzymes are postnatally induced in mesenteric lymph node (MLN) dendritic cells (DCs) and MLN stromal cells. RALDH enzyme ac

  2. Weight loss after gastric bypass surgery in women is followed by a metabolically favorable decrease in 11beta-hydroxysteroid dehydrogenase 1 expression in subcutaneous adipose tissue

    DEFF Research Database (Denmark)

    Simonyte, Kotryna; Olsson, Tommy; Näslund, Ingmar;

    2010-01-01

    The role of 11beta-hydroxysteroid dehydrogenase 1 (11beta-HSD1) in the pathogenesis of obesity has been elucidated in humans and in various rodent models. Obesity is accompanied by disturbances in glucocorticoid metabolism, circulating adipokine levels, and fatty acid (FA) reesterification. This ...

  3. 假坚强芽孢杆菌丙氨酸脱氢酶的原核表达纯化与结晶%Prokaryotic Expression,Purification and Crystallization of Alanine Dehydrogenase in Bacillus pseudofirmus

    Institute of Scientific and Technical Information of China (English)

    唐昭娜; 张翠英; 胡平雄; 易秋分; 杨江丽; 董辉

    2015-01-01

    丙氨酸脱氢酶(alanine dehydrogenase,Ald)是一种NAD+依赖性的氨基酸脱氢酶,能可逆地催化丙氨酸氧化脱氨生成丙酮酸和氨.实验以假坚强芽孢杆菌的丙氨酸脱氢酶为研究对象,将目的基因克隆到 pET-22,b(+)原核表达载体上,并在大肠杆菌中完成蛋白的高效表达.通过镍离子亲和层析、离子交换层析和凝胶过滤层析等纯化方法,得到了高纯度的目的蛋白.利用气相扩散法对目的蛋白进行结晶,最终得到分辨率为0.31,nm的蛋白晶体.%Alanine dehydrogenase(Ald)is a NAD+-dependent amino acid dehydrogenase. It catalyzes the reversible oxida-tive deamination of L-alanine to pyruvate and ammonia. An Ald gene from Bacillus pseudofirmus was cloned into the pro-karyotic expression vector pET-22,b(+)and the Ald protein was overexpressed inEscherichia coli. The Ald protein was purified by Ni2+-chelating affinity chromatography,anion-exchange chromatography and gel filtration chromatography. Crystals were grown with the vapour-diffusion method and diffracted to 0.31,nm resolution.

  4. Transforming growth factor-β1 and epidermal growth factor decrease the expression of 17β(-hydroxysteroid dehy-drogenase type 2 in endo-metrial carcinoma cells

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Estradiol (E2) is the major molecular form of estrogens. Its biological effects are determined by estrogen receptors and intracellular E2 concentration in target cells. Regulation of intracellular E2 concentration involves the action of 17β(-hydroxysteroid dehydrogenase (17HSD) type 2, the enzyme inactivating E2 to estrone. It has been demonstrated that 17HSD type 2 is expressed in normal endometrial epithelia and emdometrial carcinoma cells (RL 95-2). However, the regulatory mechanism of 17HSD type 2 expression in emdometrial cancer cells remains unknown. In the present study, the effects of transforming growth factor-(1 (TGF-β1) and epidermal growth factor (EGF) on 17HSD type 2 expression in RL 95-2 cells have been investigated using enzyme activity assay and Northern blot analysis. After stimulation with TGF-β1 or EGF, the in vivo oxidative 17HSD activity in RL 95-2 cells was significantly decreased. It appeared that the inhibitory effect of TGF-β1 and EGF on the enzyme activity of 17HSD type 2 is dose- and time-dependent. Northern blot analysis further revealed that treatment of cells for 48 h with 10 ng/mL TGF-1β And 50 ng/mL EGF reduced the expression 17HSD type 2 mRNA to 30% and 20% of the control level, respectively. The data demonstrate that 17HSD type 2 expression in endometrial carcinoma cells is down-regulated by certain growth factors.

  5. Glucose-6-phosphate dehydrogenase deficiency

    Science.gov (United States)

    ... medlineplus.gov/ency/article/000528.htm Glucose-6-phosphate dehydrogenase deficiency To use the sharing features on this page, please enable JavaScript. Glucose-6-phosphate dehydrogenase (G6PD) deficiency is a condition in which ...

  6. Metabolomic comparison between cells over-expressing isocitrate dehydrogenase 1 and 2 mutants and the effects of an inhibitor on the metabolism.

    Science.gov (United States)

    Wen, He; Cho, Hye Rim; Yun, Taeho; Kim, Hyeonjin; Park, Chul-Kee; Lee, Se-Hoon; Choi, Seung Hong; Park, Sunghyouk

    2015-01-01

    The R132H and R172K mutations of isocitrate dehydrogenase 1 and 2 (IDH1 and IDH2) have neomorphic activity of generating 2-hydroxyglutarate (2-HG) which has been implicated in the oncogenesis. Although similarities in structure and enzyme activity for the two isotypic mutations have been suggested, the difference in their cellular localization and biochemical properties suggests differential effects on the metabolic oncogenesis. Using U87 cells transfected with either wild-type (WT) and mutant (MT) IDH genes, the MT-IDH1 and MT-IDH2 cells were compared with NMR-based metabolomics. When normalized with the respective WT-IDH cells, the general metabolic shifts of MT-IDH1 and IDH2 were almost opposite. Subsequent analysis with LC-MS and metabolic pathway mapping showed that key metabolites in pentose phosphate pathway and tricarboxylic acid cycle are disproportionately altered in the two mutants, suggesting different activities in the key metabolic pathways. Notably, lactate level was lower in MT-IDH2 cells which produced more 2-HG than MT-IDH1 cells, indicating that the Warburg effects can be overridden by the production of 2-HG. We also found that the effect of a mutant enzyme inhibitor is mainly reduction of the 2-HG level rather than general metabolic normalization. Overall, the metabolic alterations in the MT-IDH1 and 2 can be different and seem to be commensurate with the degree of 2-HG production. The R132H and R172K mutations of isocitrate dehydrogenase 1 and 2, respectively, (IDH1 and IDH2) have neomorphic activity of generating 2-hydroxyglutarate (2-HG) which has been implicated in oncogenesis. The mutant cell's metabolic shifts from the respective wild type cells were almost opposite, with lactate level being lower in the IDH2 mutant only, implicating an overridden Warburg effect. The metabolic effect of an IDH1 mutant inhibitor was limited to 2-HG lowering.

  7. Studies on lipoamide dehydrogenase.

    NARCIS (Netherlands)

    Benen, J.A.E.

    1992-01-01

    At the onset of the investigations described in this thesis progress was being made on the elucidation of the crystal structure of the Azotobactervinelandii lipoamide dehydrogenase. Also the gene encoding this enzyme was cloned in our laboratory. By this, a firm basis was laid to start site directed

  8. Thymidylate synthase, dihydropyrimidine dehydrogenase, ERCC1, and thymidine phosphorylase gene expression in primary and metastatic gastrointestinal adenocarcinoma tissue in patients treated on a phase I trial of oxaliplatin and capecitabine

    Directory of Open Access Journals (Sweden)

    Danenberg Kathleen D

    2008-12-01

    Full Text Available Abstract Background Over-expression of thymidylate synthase (TS and dihydropyrimidine dehydrogenase (DPD in tumor tissue is associated with insensitivity to 5-fluorouracil (5-FU. Over-expression of ERCC1 correlates with insensitivity to oxaliplatin (OX therapy, while high thymidine phosphorylase (TP levels predict for increased sensitivity to capecitabine (Xel. Methods Biopsies of metastatic tumor were taken before OX (130 mg/m2 day 1 given with Xel (1200–3000 mg/m2 in two divided doses days 1–5 and 8–12 every 3-weeks. Micro-dissected metastatic and primary tumors were analyzed for relative gene expression by real-time quantitative polymerase chain reaction. The clinical protocol prospectively identified the molecular targets of interest that would be tested. Endpoints for the molecular analyses were correlation of median, first and third quartiles for relative gene expression of each target with response, time to treatment failure (TTF, and survival. Results Among 91 patients participating in this trial; 97% had colorectal cancer. The median number of prior chemotherapy regimens was 2, and most had prior 5-FU and irinotecan. In paired samples, median mRNA levels were significantly higher in metastatic versus primary tumor (-fold: TS (1.9, DPD (3.8, ERCC1 (2.1 and TP (1.6. A strong positive correlation was noted between DPD and TP mRNA levels in both primary (r = 0.693, p Conclusion Target gene expression in primary tumor was significantly lower than that in paired metastatic tissue. High ERCC1 mRNA levels in metastatic tumor was associated with a shorter TTF. Lower expression of TS mRNA correlated with a lower chance of early PD with XelOX therapy and improved overall survival.

  9. Expression pattern, ethanol-metabolizing activities, and cellular localization of alcohol and aldehyde dehydrogenases in human large bowel: association of the functional polymorphisms of ADH and ALDH genes with hemorrhoids and colorectal cancer.

    Science.gov (United States)

    Chiang, Chien-Ping; Jao, Shu-Wen; Lee, Shiao-Pieng; Chen, Pei-Chi; Chung, Chia-Chi; Lee, Shou-Lun; Nieh, Shin; Yin, Shih-Jiun

    2012-02-01

    Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) are principal enzymes responsible for metabolism of ethanol. Functional polymorphisms of ADH1B, ADH1C, and ALDH2 genes occur among racial populations. The goal of this study was to systematically determine the functional expressions and cellular localization of ADHs and ALDHs in human rectal mucosa, the lesions of adenocarcinoma and hemorrhoid, and the genetic association of allelic variations of ADH and ALDH with large bowel disorders. Twenty-one surgical specimens of rectal adenocarcinoma and the adjacent normal mucosa, including 16 paired tissues of rectal tumor, normal mucosae of rectum and sigmoid colon from the same individuals, and 18 surgical mixed hemorrhoid specimens and leukocyte DNA samples from 103 colorectal cancer patients, 67 hemorrhoid patients, and 545 control subjects recruited in previous study, were investigated. The isozyme/allozyme expression patterns of ADH and ALDH were identified by isoelectric focusing and the activities were assayed spectrophotometrically. The protein contents of ADH/ALDH isozymes were determined by immunoblotting using the corresponding purified class-specific antibodies; the cellular activity and protein localizations were detected by immunohistochemistry and histochemistry, respectively. Genotypes of ADH1B, ADH1C, and ALDH2 were determined by polymerase chain reaction-restriction fragment length polymorphisms. At 33mM ethanol, pH 7.5, the activity of ADH1C*1/1 phenotypes exhibited 87% higher than that of the ADH1C*1/*2 phenotypes in normal rectal mucosa. The activity of ALDH2-active phenotypes of rectal mucosa was 33% greater than ALDH2-inactive phenotypes at 200μM acetaldehyde. The protein contents in normal rectal mucosa were in the following order: ADH1>ALDH2>ADH3≈ALDH1A1, whereas those of ADH2, ADH4, and ALDH3A1 were fairly low. Both activity and content of ADH1 were significantly decreased in rectal tumors, whereas the ALDH activity remained

  10. Expression of the human isoform of glutamate dehydrogenase, hGDH2, augments TCA cycle capacity and oxidative metabolism of glutamate during glucose deprivation in astrocytes

    DEFF Research Database (Denmark)

    Nissen, Jakob D; Lykke, Kasper; Bryk, Jaroslaw

    2016-01-01

    including CO2 , respectively. We conclude that hGDH2 expression increases capacity for uptake and oxidative metabolism of glutamate, particularly during increased workload and aglycemia. Additionally, hGDH2 expression increased utilization of branched-chain amino acids (BCAA) during aglycemia and caused...... a general decrease in oxidative glucose metabolism. We speculate, that expression of hGDH2 allows astrocytes to spare glucose and utilize BCAAs during substrate shortages. These findings support the proposed role of hGDH2 in astrocytes as an important fail-safe during situations of intense glutamatergic...

  11. The relationship between third-codon position nucleotide content, codon bias, mRNA secondary structure and gene expression in the drosophilid alcohol dehydrogenase genes Adh and Adhr.

    Science.gov (United States)

    Carlini, D B; Chen, Y; Stephan, W

    2001-01-01

    To gain insights into the relationship between codon bias, mRNA secondary structure, third-codon position nucleotide distribution, and gene expression, we predicted secondary structures in two related drosophilid genes, Adh and Adhr, which differ in degree of codon bias and level of gene expression. Individual structural elements (helices) were inferred using the comparative method. For each gene, four types of randomization simulations were performed to maintain/remove codon bias and/or to maintain or alter third-codon position nucleotide composition (N3). In the weakly expressed, weakly biased gene Adhr, the potential for secondary structure formation was found to be much stronger than in the highly expressed, highly biased gene Adh. This is consistent with the observation of approximately equal G and C percentages in Adhr ( approximately 31% across species), whereas in Adh the N3 distribution is shifted toward C (42% across species). Perturbing the N3 distribution to approximately equal amounts of A, G, C, and T increases the potential for secondary structure formation in Adh, but decreases it in Adhr. On the other hand, simulations that reduce codon bias without changing N3 content indicate that codon bias per se has only a weak effect on the formation of secondary structures. These results suggest that, for these two drosophilid genes, secondary structure is a relatively independent, negative regulator of gene expression. Whereas the degree of codon bias is positively correlated with level of gene expression, strong individual secondary structural elements may be selected for to retard mRNA translation and to decrease gene expression. PMID:11606539

  12. 酮古龙酸菌山梨醇脱氢酶的原核表达及活性检测%Prokaryotic Expression and Enzyme Activity Analysis of a D-Sorbi-tol Dehydrogenase of Ketogulonigenium vulgare

    Institute of Scientific and Technical Information of China (English)

    赵楠; 熊向华; 葛欣; 汪建华; 夏焕章; 张惟材

    2013-01-01

    Objective: To clone a D-sorbitol dehydrogenase(SLDH) gene sldh from Ketogulonigenium vulgare Y25 and investigate its expression and biological activity in E.coli. Methods: The sldh gene was amplified from K.vul-gare Y25 genome, then constructed into the pTIG vector. After the expression bacteria strain E.coli BL21(DE3) transformed with the recombinant plasmid was induced by IPTG, the whole cell, the supernatant and pellet of the cellular lysate were examined by SDS-PAGE. Using D-sorbitol as a substrate, the biological activity of the expres-sion product was analyzed by Native-PAGE, the bioconversion in vitro and resting cells assay. Results: The length of amplified fragment was 1740 bp as expected and the expression plasmid pTIG-sldh was successfully con-structed. It was revealed that the molecular weight of soluble expression protein band was about 58 kD by SDS-PAGE analysis. The result of Native-PAGE demonstrated that the expression product possesses dehydrogenase activity. In the bioconversion in vitro and resting cell experiment, L-sorbose was detected through the TLC assay. Conclusion: SLDH from K.vulgare was successfully solubly expressed in E.coli BL21(DE3) and transform D-sorbi-tol to L-sorbose by dehydrogenation.%目的:克隆酮古龙酸菌Y25的山梨醇脱氢酶基因sldh,在大肠杆菌中进行表达并检测表达产物的活性。方法:以酮古龙酸菌Y25基因组DNA为模板,PCR扩增sldh基因,连接到表达载体pTIG,转入大肠杆菌BL21(DE3), IPTG诱导表达;取表达菌体、菌体裂解上清和沉淀进行SDS-PAGE分析;以山梨醇为底物,通过活性电泳、体外转化及休止细胞转化进行sldh基因表达产物的活性检测。结果:扩增得到1740 bp的山梨醇脱氢酶基因,构建了表达质粒pTIG-sldh并在大肠杆菌中获得表达,SDS-PAGE结果显示表达产物为可溶性形式,相对分子质量约58×103;活性电泳结果说明表达产物在以山

  13. 殊异韦荣菌中乳酸脱氢酶重组蛋白的表达、纯化及活性分析%The recombinant expression, purification and activity analysis of lactate dehydrogenase in Veillonella dispar

    Institute of Scientific and Technical Information of China (English)

    何钟勤; 钟丞; 高心; 薛莹; 孙晓宇; 刘晓红

    2012-01-01

    Objective To determine dependence lactate dehydrogenase activity in Veillonella dispar.Methods Transformed the recombinant plasmid pET-28a-LDH in BL21 (DE3) and Rosetta(DE3).Recombinant lactate dehydrogenase(LDH) protein was induced at different conditions.Induction condition was optimized to obtain proper yield of recombinant protein.After purification by HisTRAP FF column,the protein activity was determined with LDH reactive kit.Results Sodium dodecylsulfate-polyacrylamide gel electrophoresis showed that the best protein expression conditions were isopropylthio-β-D-galactoside (IPTG)end for 0.4 mmol/L concentration in 30 degrees to induce 8 hours,or IPTG end for 0.4 mmol/L concentration in 30 degrees to induce 6 hours.Through the analysis of BandScan 5.0,the expression in BL21 (DE3) was 9.0%,higher than 6.1% in Rosetta(DE3).After purification by HisTRAP FF column,the protein active value of 13.79.Conclusions Recombinant LDH protein could be induced by IPTG with an optimal condition.%目的 进一步测定殊异韦荣菌中依赖性乳酸脱氢酶(lactate dehydrogenase,LDH)的活性,以期为研究该酶的具体功能及作用机制奠定基础,并为龋病预防和治疗提供新的思路.方法 重组质粒转入大肠杆菌BL21(DE3)和Rosetta(DE3)中,采用不同时间及6种不同浓度的异丙基硫代-β-D-半乳糖苷(isopropyhhio-β-D-galactoside,IPTG)诱导乳酸脱氢酶蛋白表达,选择最佳条件诱导LDH蛋白表达.并经His-标记蛋白纯化柱(HisTRAP FF柱)提纯,用LDH活性试剂盒测定蛋白活性.结果 pET-28a-LDH转入BL21(DE3)和Rosetta(DE3)中十二烷基硫酸钠-聚丙烯酰胺凝胶电泳显示最适表达条件分别为IPTG终浓度0.4 mmol/L、30℃诱导8h,IPTG终浓度0.4 mmol/L、30 ℃诱导6h.经BandScan 5.0软件分析,pET-28a-LDH质粒转化BL21(DE3)表达相对含量为9.0%,高于Rosetta(DE3)的6.1%;LDH活性试剂盒测定的蛋白活性值为13.79.结论 本项研究获得了LDH蛋白的最适诱导条

  14. 15 Hypoxyprostaglandin dehydrogenase. A review

    DEFF Research Database (Denmark)

    Hansen, Harald S.

    1976-01-01

    A review is given on the enzyme 15 hydroxyprostaglandin dehydrogenase. The determination, activity, distribution, purification, properties and physiological aspects are discussed. 128 references.......A review is given on the enzyme 15 hydroxyprostaglandin dehydrogenase. The determination, activity, distribution, purification, properties and physiological aspects are discussed. 128 references....

  15. Differential Expression of Malate Dehydrogenase and Isocitrate Dehydrogenase in Diapaused Ladybird, Coccinella septempunctata L%苹果酸脱氢酶与异柠檬酸脱氢酶在滞育七星瓢虫中的差异表达

    Institute of Scientific and Technical Information of China (English)

    刘遥; 张礼生; 陈红印; 黄凤霞; 蒋莎; 任小云

    2014-01-01

    To analyze the categories and functions of the diapause related proteins in ladybird, Coccinella septempunctata, proteomics methods, such as two-dimensional electrophoresis, ESI-QUAD-TOF and bioinformatics, were used to identify the proteins with more than 2 folds of expression quantity. Mascot database search determined two matching proteins which showed different expression and are associated with the Krebs cycle, malate dehydrogenase (gi|212508346) and isocitrate dehydrogenase (gi|21392222), which were up-regulated and down-regulated, respectively. We analyzed the possible reasons and provided a theoretical basis for the diapauses environmental regulation at the protein level.%为分析七星瓢虫滞育相关蛋白质的类别和功能,在滞育调控及滞育后生物学研究的基础上,应用双向电泳、质谱分析(ESI-QUAD-TOF)、生物信息学等蛋白质组学方法,对表达量存在2倍及以上差异且差异显著的蛋白点进行鉴定。应用 Mascot 软件进行数据库检索,根据数据的匹配程度鉴定蛋白质。所得蛋白质中,参与三羧酸循环的两种关键酶呈现差异性表达,其中苹果酸脱氢酶(gi|212508346)呈上调表达,异柠檬酸脱氢酶(gi|21392222)则呈下调表达。苹果酸脱氢酶的增加,推测与滞育状态下的生理需求相关:一方面与昆虫对 NAD 的合成和利用有关,另一方面或是七星瓢虫应对滞育环境条件的一种应激方式,与正常个体的代谢通路相比,滞育个体开启了另外的代谢通路以适应环境条件的改变。异柠檬酸脱氢酶作为三羧酸循环中起关键调节作用的限速酶,在滞育个体中下调表达,或反映了三羧酸循环整体速率的降低,表现在滞育七星瓢虫体内维持了低水平的能量代谢。本文的研究结果,为从蛋白质水平深入揭示七星瓢虫滞育调控及其机理提供一定的参考。

  16. High performance enzyme fuel cells using a genetically expressed FAD-dependent glucose dehydrogenase α-subunit of Burkholderia cepacia immobilized in a carbon nanotube electrode for low glucose conditions.

    Science.gov (United States)

    Fapyane, Deby; Lee, Soo-Jin; Kang, Seo-Hee; Lim, Du-Hyun; Cho, Kwon-Koo; Nam, Tae-hyun; Ahn, Jae-Pyoung; Ahn, Jou-Hyeon; Kim, Seon-Won; Chang, In Seop

    2013-06-28

    FAD-dependent glucose dehydrogenase (FAD-GDH) of Burkholderia cepacia was successfully expressed in Escherichia coli and subsequently purified in order to use it as an anode catalyst for enzyme fuel cells. The purified enzyme has a low Km value (high affinity) towards glucose, which is 463.8 μM, up to 2-fold exponential range lower compared to glucose oxidase. The heterogeneous electron transfer coefficient (Ks) of FAD-GDH-menadione on a glassy carbon electrode was 10.73 s(-1), which is 3-fold higher than that of GOX-menadione, 3.68 s(-1). FAD-GDH was able to maintain its native glucose affinity during immobilization in the carbon nanotube and operation of enzyme fuel cells. FAD-GDH-menadione showed 3-fold higher power density, 799.4 ± 51.44 μW cm(-2), than the GOX-menadione system, 308.03 ± 17.93 μW cm(-2), under low glucose concentration, 5 mM, which is the concentration in normal physiological fluid.

  17. Expression of 17?-hydroxysteroid dehydrogenase and the effects of LH, FSH and prolactin on oestrone and 17?-oestradiol secretion in the endometrium of pigs during early pregnancy and the oestrous cycle.

    Science.gov (United States)

    Wojciechowicz, B; Kotwica, G; Zglejc, K; Waszkiewicz, E; Franczak, A

    2016-03-07

    The endometrium of pregnant and cyclic pigs is a source of oestrone (E1) and 17β-oestradiol (E2). However, the roles of LH, FSH and prolactin (PRL) as regulators of endometrial steroidogenesis, and the presence of 17β-hydroxysteroid dehydrogenase (17β-HSD) in the porcine endometrium, remain unknown. Therefore, in the present study we examined 17β-HSD expression and the effects of LH, FSH and PRL on E1 and E2 release in vitro in endometrial explants harvested from gravid pigs on Days 10-11 (embryo migration within the uterus), 12-13 (maternal recognition of pregnancy) and 15-16 (beginning of implantation) and compared them with results obtained in non-gravid pigs. The results show that: (1) endometrial 17β-HSD activity was decreased on Days 15-16 in pregnant and cyclic pigs compared with the preceding days; (2) LH, FSH and PRL increased endometrial E1 secretion on Days 10-11 and 15-16 of pregnancy and on Days 12-13 and 15-16 of the oestrous cycle; and (3) LH, FSH and PRL increased endometrial E2 secretion on Days 15-16 of pregnancy and during the days studied in the oestrous cycle. In conclusion, data suggest that LH, FSH and PRL affect endometrial secretion of estrogens in pigs.

  18. Expression of glucocorticoid receptor, mineralocorticoid receptor, and 11beta-hydroxysteroid dehydrogenase 1 and 2 in the fetal and postnatal ovine hippocampus: ontogeny and effects of prenatal glucocorticoid exposure.

    Science.gov (United States)

    Sloboda, Deborah M; Moss, Timothy J M; Li, Shaofu; Matthews, Stephen G; Challis, John R G; Newnham, John P

    2008-05-01

    To determine the expression of glucocorticoid metabolizing and action genes in the hippocampus of fetal, neonatal, and adult sheep. Pregnant ewes (or their fetuses) received intramuscular injections of saline or betamethasone (BETA, 0-5 mg/kg) at 104, 111, 118, and/or 125 days of gestation (dG). Hippocampal tissue was collected prior to (75, 84, and 101 dG), during (109 and 116 dG), or after (121, 132, and 146 dG; 6 and 12 postnatal weeks; 3.5 years of age) saline or BETA injections. Hippocampal glucocorticoid receptor (GR), mineralocorticoid receptor (MR), and 11beta-hydroxysteroid dehydrogenase (11betaHSD)1 and 11betaHSD2 mRNA levels were determined using qRT-PCR. Control animals late in gestation demonstrated a decrease in mRNA encoding GR and 11betaHSD1, whereas 11betaHSD2 was undetectable, consistent with a damping of the negative feedback influence of circulating or locally produced cortisol on the hypothalamic-pituitary-adrenal (HPA) axis. BETA-administration had transient effects on fetal GR and MR, and early in postnatal life (12 weeks of age) 11betaHSD1 mRNA was increased. Hippocampal MR mRNA was elevated in adult offspring exposed to either one or four doses of maternal BETA (Pglucocorticoid negative feedback, facilitating increased preterm HPA activity and parturition. Adult offspring of BETA-treated mothers demonstrated increased MR and 11betaHSD2 mRNA, therefore it appears that exposure of fetus to high levels of synthetic glucocorticoids may have long-lasting effects on the hippocampal expression of HPA-related genes into adulthood.

  19. 乙醇脱氢酶Ⅰ类基因全长cDNA的克隆与表达%Cloning and Expression of the Full-length cDNAs Encoding Human Class Ⅰ Alcohol Dehydrogenases

    Institute of Scientific and Technical Information of China (English)

    周文婷; 李景鹏; 崔羽; 张永红; 李世荣

    2007-01-01

    Background & Objective:Background &Objective: The class Ⅰ Alcohol Dehydrogenases (ADH) play a key role in hepatic alcohol catabolism. Human ADH is encoded by at least seven genes, and three class Ⅰ ADH genes-ADH1, ADH2 and ADH3, which encode the α, β, and γ subunit respectively, had been isolated and mapped on chromosome 4q21-q25. This experiment tends to clone the human class Ⅰ ADH and investigate its role in the hepatic alcohol catabolism. Methods: A pair of primers were designed and the full-length cDNAs encoding human Class Ⅰ ADH were cloned at one time. Class Ⅰ ADH cDNAs were amplified with RT-PCR from total RNA extracted from fetal human liver and kidney, and cloned into pGEM-T vector. To identify cDNA segments, a pair of differential primers was designed. By using them, a portion of the ADHs which encodes the segment from -4 to 296 was cloned. These cDNA segments then were detected directly when being digested with Kpn Ⅰ and Pst Ⅰ, respectively. Then all the full-length cDNAs were subcloned in the plasmid pTYB11 and expressed in E. Coli. Stably. Alcohol Dehydrogenase activity of catalyzing alcohol were monitored at 340 nm. Results: Here we had successfully the human class Ⅰ ADH cloned and the full-length cDNAs expressed in E.col.I stably. The relative activity of recombinant enzymes metabolizing ethanol was 0.81 ~1.31 U/mg,0.09 ~0.15 U/mg and 0.76~1.11 U/mg, respectively. Conclusions: In the paper, the full-length cDNAs encoding human class Ⅰ AD H were successfully cloned and expressed and the recombinant enzymes showed the activities similar to the ones isolated from liver.%目的:克隆编码人Ⅰ类乙醇脱氢酶基因,并探讨Ⅰ类乙醇脱氢酶(ADH)在乙醇的肝代谢中的作用.方法:从胎儿肝,肾提取的总RNA;经RT-PCR扩增得到cDNA并克隆至pGEM-T载体.cDNA序列用Kpn Ⅰ和Pst Ⅰ酶切鉴定,并检测其在大肠杆菌中表达活性.通过吸光法检测酶的活性.结果:成功克隆了人Ⅰ类乙

  20. Equating salivary lactate dehydrogenase (LDH) with LDH-5 expression in patients with oral squamous cell carcinoma: An insight into metabolic reprogramming of cancer cell as a predictor of aggressive phenotype.

    Science.gov (United States)

    Saluja, Tajindra Singh; Spadigam, Anita; Dhupar, Anita; Syed, Shaheen

    2016-04-01

    Oral squamous cell carcinoma (OSCC) is the sixth most common human malignancy. According to World Health Organization, oral cancer has been reported to have the highest morbidity and mortality and a survival rate of approximately 50 % at 5 years from diagnosis. This is attributed to the subjectivity in TNM staging and histological grading which may result in less than optimum treatment outcomes including tumour recurrence. One of the hallmarks of cancer is aerobic glycolysis also known as the Warburg effect. This glycolytic phenotype (hypoxic state) not only confers immortality to cancer cells, but also correlates with the belligerent behaviour of various malignancies and is reflected as an increase in the expression of lactate dehydrogenase 5 (LDH-5), the main isoform of LDH catalysing the conversion of pyruvate to lactate during glycolysis. The diagnostic role of salivary LDH in assessing the metabolic phenotype of oral cancer has not been studied. Since salivary LDH is mainly sourced from oral epithelial cells, any pathological changes in the epithelium should reflect diagnostically in saliva. Thus in our current research, we made an attempt to ascertain the biological behaviour and aggressiveness of OSCC by appraising its metabolic phenotype as indirectly reflected in salivary LDH activity. We found that salivary LDH can be used to assess the aggressiveness of different histological grades of OSCC. For the first time, an evidence of differing metabolic behaviour in similar histologic tumour grade is presented. Taken together, our study examines the inclusion of salivary LDH as potential diagnostic parameter and therapeutic index in OSCC.

  1. Cloning and expression of 6-phosphogluconate dehydrogenase alternative splicing in Volvariella volvacea%草菇6-磷酸葡萄糖酸脱氢酶基因可变剪接体克隆与表达分析

    Institute of Scientific and Technical Information of China (English)

    陈志宏; 傅梅萍; 李远峰; 陶永新; 江玉姬; 谢宝贵

    2014-01-01

    6-磷酸葡萄糖酸脱氢酶(6PGDH)是磷酸戊糖途径的限速酶,影响着细胞生命活动所需要的NADPH的产生.为揭示草菇菌丝生长的分子基础,通过克隆草菇6-磷酸葡萄糖酸脱氢酶编码基因(6gpdh)的可变剪接体,测序后进行生物信息学分析,利用表达谱和qPCR测定了它们在同核体和异核体菌株的表达量.结果显示,草菇6gpdh序列全长2 315bp,含10个内含子,第6个内含子存在内含子保留的可变剪接.在同核体和异核体菌株中,内含子保留的可变剪接体表达量低,且菌株间没显著差异,而内含子被剪接的剪接体表达量高,且异核体菌株高于同核体菌株.两种可变剪接体具有6-磷酸葡萄糖酸脱氢酶保守结构域和相似的三维结构.因此,初步分析两个可变剪切体是同工酶,内含子保留是组成型表达,表达量与菌丝生长快慢无关,内含子剪接是主效剪接方式,菌丝生长快的菌株表达量高,生长慢的菌株表达量低.%6-phosphogluconate dehydrogenase (6PGDH),one of the key enzymes in pentose phosphate pathway (PPP),is essential for research of molecular basis about the growth of mycelium in Volvariella volvacea.This paper aimed to study the role of 6PGDH in the growth of mycelium.We cloned and sequenced variants of 6gpdh gene with RT-PCR technique and performed bioinformatic analysis.The expression levels of 6gpdh in both monokaryons and heterokaryon were detected by digital gene expression profiling and qPCR.The results showed that 6gpdh gene with ten introns had two types of alternative splicing variants (6pgdhIR exhibiting 6th intron retention and 6pgdhID exhibiting 6th intron deletion).Both digital gene expression profile and qPCR showed a higher expression level of 6gpdh in heterokaryon than in any monokaryon.Nevertheless,the expression level of 6pgdhIR was low in three mycelia with little differences.Both variants could encode 6PGDH protein with conserved domain and similar tertiary

  2. 脑胶质瘤中核干细胞因子表达与IDH1基因突变分析%Analysis of expression of nucleostemin and mutations of ;isocitrate dehydrogenase 1 gene in glioma tissues

    Institute of Scientific and Technical Information of China (English)

    寿记新; 管海博; 程森

    2014-01-01

    Objective To analyze the characteristic of expression of NS and isocitrate dehydrogenase (IDH1) gene muta-tions in gliomas ,as to provide theoretical basis for the diagnosis and treatment of glioma. Methods Fifty-eight human glioma samples were analyzed. The protein expression levels of NS were measured by IHC. The polymorphisms change of IDH1 gene was detected by real-time quantitative PCR.Results Upshots immuno-histochemistry manifested that the positive expression rate of NS in high level gloma tissue was higher than that in low level glioma. Gene sequencing manifested that IDH1 gene mu-tations were observed in 16 samples having gliomas(55.2% ) ,and the mutation appeared as R132H type. By the SPSS analy-sis ,IDH1 gene mutation rate had a certain correlation with glioma pathology classification.Conclusion As the increase of path-ological level ,the expression of NS and IDH1 gene mutations rate are increased in glioma. It can provide strong evidence for the diagnosis of glioma and opened up a new research way in gene therapy for gliomas.%目的:分析胶质瘤中核干细胞因子(NS)表达和异柠檬酸脱氢酶1(IDHI)基因突变的特点,为胶质瘤的诊断、治疗提供理论依据。方法对58例原发性胶质瘤存档蜡块分析,采用免疫组织化学法检测 NS 蛋白的表达情况,应用 PCR技术检测标本中IDH1基因多态性变化。结果免疫组织化学法检测显示,在高级别胶质瘤标本中NS蛋白表达率高于低级别。经基因直接测序,16例(55.2%)出现IDH1突变,突变位点均为R132型。经统计学分析,IDH1基因突变率与胶质瘤病理分级呈正相关。结论在胶质瘤中核干细胞因子表达和ID H l基因突变率随病理级别的增加而增加,可为胶质瘤的诊断提供有力的证据,并为胶质瘤在基因治疗方面指出了新的研究方向。

  3. Michael hydratase alcohol dehydrogenase or just alcohol dehydrogenase?

    NARCIS (Netherlands)

    Resch, V.A.; Jin, J.; Chen, B.S.; Hanefeld, U.

    2014-01-01

    The Michael hydratase – alcohol dehydrogenase (MhyADH) from Alicycliphilus denitrificans was previously identified as a bi-functional enzyme performing a hydration of α,β-unsaturated ketones and subsequent oxidation of the formed alcohols. The investigations of the bi-functionality were based on a s

  4. 大肠杆菌苹果酸脱氢酶基因mdh的克隆、高效表达及酶学性质%Cloning,Expression,and Characterization of a Malate Dehydrogenase Gene from Escherichia coli

    Institute of Scientific and Technical Information of China (English)

    李倩; 徐美娟; 夏海锋; 饶志明

    2011-01-01

    Malate dehydrogenase (MDH) gene was amplified via PCR from the chromosome of Escherichia coli in this manuscript.The PCR product was cloned into the expression vector pET28a (+).The resulted recombinant plasmid was transformed into E.coli BL21 (DE3).Induced by 0.5 mmol/L IPTG, MDH, a 36KDa protein, was successfully expressed in E.coli BL21 (DE3).An active MDH was purified by Ni-NTA column affinity Chromatography, with the specific activity of 112.5 U/mg,the purification multiple of 2.62, and the recovery rate of 59%.In a preliminary study, the enzymatic properties of the purified His-tagged enzyme were characterized.It was found to have pH and temperature optima of 37 ℃ and 6.0, respectively.The enzyme was stable when pH and temperature kept in the range of 2.0 to 6.0 and blow 42 ℃, respectively.Its activity was activated by K+ dramatically, inhibited by Cu2+ , seriously inhibited by Zn2+ and Hg2+.Although alcohols have little effect on this enzyme, glycerol could dramatically improve the thermal stability of MDH.When oxaloacetic acid was used as substrate, the enzyme kinetic constants of Km and Vmax was 0.235 mmol/L and 0.47 μmol/(L · min), respectively.%以大肠杆菌基因组DNA为模板,扩增得到苹果酸脱氢酶(mdh)编码基因mdh,构建了重组菌pET-28a-mdh/BL21并成功表达了mdh,大小约36 000.选用Ni柱亲和层析法纯化具有活性的苹果酸脱氢酶(mdh),纯化后比酶活达到112.5 U/mg,纯化倍数达2.62倍,回收率为59%.并对该酶的酶学性质进行了初步研究,其中反应最适PH值为6.0,在PH值2.0~6.0范围内稳定;反应最适温度为37℃,在42℃以下酶的稳定性较好.K+对酶有明显的激活作用,Cu2+对酶有抑制作用,Hg2+和Zn2+对酶有很强的抑制作用.醇类对酶的活力影响不大,丙三醇可显著提高酶的热稳定性.酶动力学参数以草酰乙酸为底物的Km为0.235 mmol/L,Vmax为0.47 μmol/(L·min).

  5. Optimization of adsorptive immobilization of alcohol dehydrogenases.

    Science.gov (United States)

    Trivedi, Archana; Heinemann, Matthias; Spiess, Antje C; Daussmann, Thomas; Büchs, Jochen

    2005-04-01

    In this work, a systematic examination of various parameters of adsorptive immobilization of alcohol dehydrogenases (ADHs) on solid support is performed and the impact of these parameters on immobilization efficiency is studied. Depending on the source of the enzymes, these parameters differently influence the immobilization efficiency, expressed in terms of residual activity and protein loading. Residual activity of 79% was achieved with ADH from bakers' yeast (YADH) after optimizing the immobilization parameters. A step-wise drying process has been found to be more effective than one-step drying. A hypothesis of deactivation through bubble nucleation during drying of the enzyme/glass bead suspension at low drying pressure (300% residual activity was found after drying. Hyperactivation of the enzyme is probably caused by structural changes in the enzyme molecule during the drying process. ADH from Thermoanaerobacter species (ADH T) is found to be stable under drying conditions (>15 kPa) in contrast to LBADH and YADH.

  6. Gene Cloning and mRNA Expression of Glutamate Dehydrogenase in the Liver, Brain, and Intestine of the Swamp Eel, Monopterus albus (Zuiew), Exposed to Freshwater, Terrestrial Conditions, Environmental Ammonia, or Salinity Stress

    OpenAIRE

    Tok, Chia Y.; Shit F Chew; Yuen K Ip

    2011-01-01

    The swamp eel, Monopterus albus, is an obligatory air-breathing teleost which can undergo long period of emersion, has high environmental and tissue ammonia tolerance, and can survive in brackish water. We obtained a cDNA sequence of glutamate dehydrogenase (gdh), which consisted of a 133-bp 5′ UTR, a complete coding sequence region spanning 1629 bp and a 3′ UTR of approximately 717 bp, from the liver, intestine, and brain of M. albus. The translated Gdh amino acid sequence had 542 residues, ...

  7. A new dawn for plant mitochondrial NAD(P)H dehydrogenases

    DEFF Research Database (Denmark)

    Møller, I.M.

    2002-01-01

    The expression of complex I and two homologues of bacterial and yeast NADH dehydrogenases, NDA and NDB, have been studied in potato leaf mitochondria. The mRNA level of NDA is completely light dependent and shows a diurnal rhythm with a sharp maximum just after dawn. NDA protein quantity and inte...... and internal rotenone-insensitive NADH dehydrogenase activity are also light dependent. These findings suggest that NDA has a role in photorespiration and might be identical to the previously unidentified internal rotenone-insensitive NADH dehydrogenase....

  8. Crystal structure of quinone-dependent alcohol dehydrogenase from Pseudogluconobacter saccharoketogenes. A versatile dehydrogenase oxidizing alcohols and carbohydrates.

    Science.gov (United States)

    Rozeboom, Henriëtte J; Yu, Shukun; Mikkelsen, Rene; Nikolaev, Igor; Mulder, Harm J; Dijkstra, Bauke W

    2015-12-01

    The quinone-dependent alcohol dehydrogenase (PQQ-ADH, E.C. 1.1.5.2) from the Gram-negative bacterium Pseudogluconobacter saccharoketogenes IFO 14464 oxidizes primary alcohols (e.g. ethanol, butanol), secondary alcohols (monosaccharides), as well as aldehydes, polysaccharides, and cyclodextrins. The recombinant protein, expressed in Pichia pastoris, was crystallized, and three-dimensional (3D) structures of the native form, with PQQ and a Ca(2+) ion, and of the enzyme in complex with a Zn(2+) ion and a bound substrate mimic were determined at 1.72 Å and 1.84 Å resolution, respectively. PQQ-ADH displays an eight-bladed β-propeller fold, characteristic of Type I quinone-dependent methanol dehydrogenases. However, three of the four ligands of the Ca(2+) ion differ from those of related dehydrogenases and they come from different parts of the polypeptide chain. These differences result in a more open, easily accessible active site, which explains why PQQ-ADH can oxidize a broad range of substrates. The bound substrate mimic suggests Asp333 as the catalytic base. Remarkably, no vicinal disulfide bridge is present near the PQQ, which in other PQQ-dependent alcohol dehydrogenases has been proposed to be necessary for electron transfer. Instead an associated cytochrome c can approach the PQQ for direct electron transfer.

  9. Decrease in nicotinamide adenine dinucleotide dehydrogenase is related to skin pigmentation.

    Science.gov (United States)

    Nakama, Mitsuo; Murakami, Yuhko; Tanaka, Hiroshi; Nakata, Satoru

    2012-03-01

    Skin pigmentation is caused by various physical and chemical factors. It might also be influenced by changes in the physiological function of skin with aging. Nicotinamide adenine dinucleotide (NADH) dehydrogenase is an enzyme related to the mitochondrial electron transport system and plays a key role in cellular energy production. It has been reported that the functional decrease in this system causes Parkinson's disease. Another study reports that the amount of NADH dehydrogenase in heart and skeletal muscle decreases with aging. A similar decrease in the skin would probably affect its physiological function. However, no reports have examined the age-related change in levels of NADH dehydrogenase in human skin. In this study, we investigated this change and its effect on skin pigmentation using cultured human epidermal keratinocytes. The mRNA expression of NDUFA1, NDUFB7, and NDUFS2, subunits of NADH dehydrogenase, and its activity were significantly decreased in late passage keratinocytes compared to early passage cells. Conversely, the mRNA expression of melanocyte-stimulating cytokines, interleukin-1 alpha and endothelin 1, was increased in late passage cells. On the other hand, the inhibition of NADH dehydrogenase upregulated the mRNA expression of melanocyte-stimulating cytokines. Moreover, the level of NDUFB7 mRNA was lower in pigmented than in nonpigmented regions of skin in vivo. These results suggest the decrease in NADH dehydrogenase with aging to be involved in skin pigmentation.

  10. An efficient ribitol-specific dehydrogenase from Enterobacter aerogenes.

    Science.gov (United States)

    Singh, Ranjitha; Singh, Raushan; Kim, In-Won; Sigdel, Sujan; Kalia, Vipin C; Kang, Yun Chan; Lee, Jung-Kul

    2015-05-01

    An NAD(+)-dependent ribitol dehydrogenase from Enterobacter aerogenes KCTC 2190 (EaRDH) was cloned and successfully expressed in Escherichia coli. The complete 729-bp gene was amplified, cloned, expressed, and subsequently purified in an active soluble form using nickel affinity chromatography. The enzyme had an optimal pH and temperature of 11.0 and 45°C, respectively. Among various polyols, EaRDH exhibited activity only toward ribitol, with Km, Vmax, and kcat/Km values of 10.3mM, 185Umg(-1), and 30.9s(-1)mM(-1), respectively. The enzyme showed strong preference for NAD(+) and displayed no detectable activity with NADP(+). Homology modeling and sequence analysis of EaRDH, along with its biochemical properties, confirmed that EaRDH belongs to the family of NAD(+)-dependent ribitol dehydrogenases, a member of short-chain dehydrogenase/reductase (SCOR) family. EaRDH showed the highest activity and unique substrate specificity among all known RDHs. Homology modeling and docking analysis shed light on the molecular basis of its unusually high activity and substrate specificity.

  11. 猪带绦虫苹果酸脱氢酶基因的克隆表达及免疫学分析%Expression and purification of malate dehydrogenase gene in Taenia solium and immunologic analysis of the recombinant proteins

    Institute of Scientific and Technical Information of China (English)

    江楠; 席晓兰; 王杰; 戴佳琳; 廖兴江; 黄江

    2011-01-01

    目的 对猪带绦虫苹果酸脱氢酶基因(malate dehydrogenase,MDH)进行克隆,表达及免疫学特性的初步研究.方法 将猪带绦虫MDH基因克隆到原核表达质粒pET-28a(+)中,在大肠埃希菌BL21/DE3中用异丙基-β-D-半乳糖苷(IPTG)诱导表达,表达产物通过十二烷基磺酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)进行鉴定,用镍离子金属螯合剂亲和层析柱进行纯化,纯化的重组蛋白用蛋白印迹(Western Blot)进行免疫学分析.结果 成功构建pET-28a(+)-MDH重组质粒,并获得高纯度蛋白,该重组蛋白可被其免疫SD大鼠血清识别,同时也能被感染猪带绦虫的病人及猪、感染牛带绦虫病人及感染亚带绦虫病人血清所识别.结论 猪带绦虫苹果酸脱氢酶基因可在原核表达系统中获得具有免疫学活性的高效表达,为进一步研究该蛋白的功能奠定了基础.%The objective of this study was to clone and express the gene named as malate dehydrogenase gene (MDH) in Taenia Solium, and to analyze the immunogenicity of its recombinant protein. The coding region of MDH was amplified with PCR, cloned into the prokaryotic expression vector pET-28a(+) and expressed in E. coli BL21/DE3 with IPTG induction. In addition, the immunogenicity of the purified recombinant proteins was analyzed by Western blotting. PCR, double enzyme digestion and DNA sequencing confirmed that the recombinant expression plasmid was successfully constructed. The expression products were obtained and purified by His-Ni2+ affinity chromatography. Western blotting analysis of MDH recombinant protein testified that these proteins could be recognized by sera of the patients infected with T. asiatica and T. rhynchus saginatus. Results suggested that the MDH gene of T. solium has been cloned and expressed, and the purified protein has been confirmed with immunogenicity.

  12. Hydroxysteroid dehydrogenases (HSDs) in bacteria: a bioinformatic perspective.

    Science.gov (United States)

    Kisiela, Michael; Skarka, Adam; Ebert, Bettina; Maser, Edmund

    2012-03-01

    Steroidal compounds including cholesterol, bile acids and steroid hormones play a central role in various physiological processes such as cell signaling, growth, reproduction, and energy homeostasis. Hydroxysteroid dehydrogenases (HSDs), which belong to the superfamily of short-chain dehydrogenases/reductases (SDR) or aldo-keto reductases (AKR), are important enzymes involved in the steroid hormone metabolism. HSDs function as an enzymatic switch that controls the access of receptor-active steroids to nuclear hormone receptors and thereby mediate a fine-tuning of the steroid response. The aim of this study was the identification of classified functional HSDs and the bioinformatic annotation of these proteins in all complete sequenced bacterial genomes followed by a phylogenetic analysis. For the bioinformatic annotation we constructed specific hidden Markov models in an iterative approach to provide a reliable identification for the specific catalytic groups of HSDs. Here, we show a detailed phylogenetic analysis of 3α-, 7α-, 12α-HSDs and two further functional related enzymes (3-ketosteroid-Δ(1)-dehydrogenase, 3-ketosteroid-Δ(4)(5α)-dehydrogenase) from the superfamily of SDRs. For some bacteria that have been previously reported to posses a specific HSD activity, we could annotate the corresponding HSD protein. The dominating phyla that were identified to express HSDs were that of Actinobacteria, Proteobacteria, and Firmicutes. Moreover, some evolutionarily more ancient microorganisms (e.g., Cyanobacteria and Euryachaeota) were found as well. A large number of HSD-expressing bacteria constitute the normal human gastro-intestinal flora. Another group of bacteria were originally isolated from natural habitats like seawater, soil, marine and permafrost sediments. These bacteria include polycyclic aromatic hydrocarbons-degrading species such as Pseudomonas, Burkholderia and Rhodococcus. In conclusion, HSDs are found in a wide variety of microorganisms including

  13. The Clone and Expression of 3-Ketosteroid-1-dehydrogenase from Mycobacterium Neoaurum NwlB-01%分枝杆菌Mycobacterium Neoaurum NwIB-013-甾酮-Δ1-脱氢酶基因的克隆表达

    Institute of Scientific and Technical Information of China (English)

    张成刚; 王风清; 魏东芝

    2011-01-01

    The primers were designed through analyzing the genome sequence of two known 3-ketosteroid-△1 -dehydrogenase in Mycobacterium, and the conservative region was obtained with Mycobacterium neoaurum NwIB-01 as the template. Through genome walking, the sequence after the conservative region about 1500 bp long was got. Then pTQ002 was constructed as the expression vector, and the kstD was expressed in E. Coli DH5α. The 3-ketosteroid-△1 -dehydrogenase activity of Mycobacterium neoaurum NwIB-01 was (0. 37±0. 05)U ? mL-1, about half of the former one.%通过分析已知两种分枝杆菌的3-甾酮-△1-脱氢酶(kstD)碱基保守序列,设计简并引物,以甾醇降解菌株Mycobacterium neoaurum NwIB-01的DNA作模板,得到一个kstD基因片段,通过染色体走读,得到其完整的阅读框.以pUC18为异源表达载体,构建pTQ002表达质粒,在E.coli DH5α中对kstD进行了胞内活性表达,测定Mycobacterium neoaurum NwIB-01 kstD酶活为(0.37±0.05)U·mL-1,约为原酶活的一半,为构建高效转化生成3-酮基-1,4-二烯类固醇的基因工程菌奠定了基础.

  14. Change in ATP-binding cassette B1/19, glutamine synthetase and alcohol dehydrogenase gene expression during root elongation in Betula pendula Roth and Alnus glutinosa L. Gaertn in response to leachate and leonardite humic substances.

    Science.gov (United States)

    Tahiri, Abdelghani; Delporte, Fabienne; Muhovski, Yordan; Ongena, Marc; Thonart, Philippe; Druart, Philippe

    2016-01-01

    Humic substances (HS) are complex and heterogeneous compounds of humified organic matter resulting from the chemical and microbiological decomposition of organic residues. HS have a positive effect on plant growth and development by improving soil structure and fertility. They have long been recognized as plant growth-promoting substances, particularly with regard to influencing nutrient uptake, root growth and architecture. The biochemical and molecular mechanisms through which HS influence plant physiology are not well understood. This study evaluated the bioactivity of landfill leachate and leonardite HS on alder (Alnus glutinosa L. Gaertn) and birch (Betula pendula Roth) during root elongation in vitro. Changes in root development were studied in relation to auxin, carbon and nitrogen metabolisms, as well as to the stress adaptive response. The cDNA fragments of putative genes encoding two ATP-binding cassette (ABC) transporters (ABCB1 and ABCB19) belonging to the B subfamily of plant ABC auxin transporters were cloned and sequenced. Molecular data indicate that HS and their humic acid (HA) fractions induce root growth by influencing polar auxin transport (PAT), as illustrated by the modulation of the ABCB transporter transcript levels (ABCB1 and ABCB19). There were also changes in alcohol dehydrogenase (ADH) and glutamine synthetase (GS) gene transcript levels in response to HS exposure. These findings confirmed that humic matter affects plant growth and development through various metabolic pathways, including hormonal, carbon and nitrogen metabolisms and stress response or signalization.

  15. 柳蚕异柠檬酸脱氢酶基因cDNA的克隆与表达分析%Cloning and Expression Analysis of Isocitrate Dehydrogenase Gene From Actias selene Hubner

    Institute of Scientific and Technical Information of China (English)

    吴祥; 曹甲; 刘朝良; 朱保建; 魏国清; 王在贵; 姚立虎; 钱岑; 汤良文; 周炎

    2009-01-01

    异柠檬酸脱氢酶(isocitrate dehydrogenase,IDH)是生物体内一种重要的氧化还原酶.根据已报道的烟酰胺腺嘌呤二核苷酸磷酸异柠檬酸脱氢酶(NADP-IDH)基因的保守性序列设计引物,以柳蚕(Actias selene Hubner)蛹脂肪体cDNA为模板,经PCR扩增获得了柳蚕IDH基因的部分序列.该序列长1 269 bp,编码412个氨基酸,与家蚕IDH基因的cDNA序列同源性达82.5%.柳蚕IDH与果蝇、赤拟谷盗、斑马鱼、人、大鼠、库蚊、人体虱、恶性疟原虫IDH的氨基酸序列同源性在70%左右,具有较高的保守性.半定量PCR检测结果表明,柳蚕IDH基因在蛹期不同组织中均有表达,且表达量没有显著差异.

  16. Characterization of two β-decarboxylating dehydrogenases from Sulfolobus acidocaldarius.

    Science.gov (United States)

    Takahashi, Kento; Nakanishi, Fumika; Tomita, Takeo; Akiyama, Nagisa; Lassak, Kerstin; Albers, Sonja-Verena; Kuzuyama, Tomohisa; Nishiyama, Makoto

    2016-11-01

    Sulfolobus acidocaldarius, a hyperthermoacidophilic archaeon, possesses two β-decarboxylating dehydrogenase genes, saci_0600 and saci_2375, in its genome, which suggests that it uses these enzymes for three similar reactions in lysine biosynthesis through 2-aminoadipate, leucine biosynthesis, and the tricarboxylic acid cycle. To elucidate their roles, these two genes were expressed in Escherichia coli in the present study and their gene products were characterized. Saci_0600 recognized 3-isopropylmalate as a substrate, but exhibited slight and no activity for homoisocitrate and isocitrate, respectively. Saci_2375 exhibited distinct and similar activities for isocitrate and homoisocitrate, but no detectable activity for 3-isopropylmalate. These results suggest that Saci_0600 is a 3-isopropylmalate dehydrogenase for leucine biosynthesis and Saci_2375 is a dual function enzyme serving as isocitrate-homoisocitrate dehydrogenase. The crystal structure of Saci_0600 was determined as a closed-form complex that binds 3-isopropylmalate and Mg(2+), thereby revealing the structural basis for the extreme thermostability and novel-type recognition of the 3-isopropyl moiety of the substrate.

  17. Characterization of Flavin-Containing Opine Dehydrogenase from Bacteria.

    Directory of Open Access Journals (Sweden)

    Seiya Watanabe

    Full Text Available Opines, in particular nopaline and octopine, are specific compounds found in crown gall tumor tissues induced by infections with Agrobacterium species, and are synthesized by well-studied NAD(PH-dependent dehydrogenases (synthases, which catalyze the reductive condensation of α-ketoglutarate or pyruvate with L-arginine. The corresponding genes are transferred into plant cells via a tumor-inducing (Ti plasmid. In addition to the reverse oxidative reaction(s, the genes noxB-noxA and ooxB-ooxA are considered to be involved in opine catabolism as (membrane-associated oxidases; however, their properties have not yet been elucidated in detail due to the difficulties associated with purification (and preservation. We herein successfully expressed Nox/Oox-like genes from Pseudomonas putida in P. putida cells. The purified protein consisted of different α-, β-, and γ-subunits encoded by the OdhA, OdhB, and OdhC genes, which were arranged in tandem on the chromosome (OdhB-C-A, and exhibited dehydrogenase (but not oxidase activity toward nopaline in the presence of artificial electron acceptors such as 2,6-dichloroindophenol. The enzyme contained FAD, FMN, and [2Fe-2S]-iron sulfur as prosthetic groups. On the other hand, the gene cluster from Bradyrhizobium japonicum consisted of OdhB1-C-A-B2, from which two proteins, OdhAB1C and OdhAB2C, appeared through the assembly of each β-subunit together with common α- and γ-subunits. A poor phylogenetic relationship was detected between OdhB1 and OdhB2 in spite of them both functioning as octopine dehydrogenases, which provided clear evidence for the acquisition of novel functions by "subunit-exchange". To the best of our knowledge, this is the first study to have examined flavin-containing opine dehydrogenase.

  18. Heterologous Expression and Sequence Analysis of Isocitrate Dehydrogenase from Streptomyces lividans TK54%变铅青链霉菌异柠檬酸脱氢酶的异源表达及序列分析

    Institute of Scientific and Technical Information of China (English)

    张贝贝; 徐琴; 黄恩启; 刘爱民; 郝家胜; 朱国萍

    2009-01-01

    通过同源性引物成功扩增和克隆了变铅青链霉菌(Streptomyces lividans)TK54的异柠檬酸脱氢酶(isocitrate dehydrogenase, IDH) (简称SlIDH)基因icd (GenBank登录号为EU661252).icd的起始密码子为GTG,GC含量为69.55 %,显示了链霉菌基因的高GC含量特征,实现了SlIDH在E.coli中的异源高效表达.0.5 mmol/L的IPTG为最佳诱导条件.SlIDH的分子量约为80 kD.在Mn~(2+)或Mg~(2+)条件下,SlIDH以NADP~+为辅酶时的活性分别为7.94 U/mg及4.00 U/mg,以NAD~+为辅酶时的活性分别为0.58 U/mg及0.27 U/mg,SlIDH更偏爱以NADP~+为辅酶.与不同种属单体IDH的氨基酸序列比对显示,SlIDH与单体IDH的序列一致性均在60 %以上.因此本工作首次以实验性证据初步鉴定了SlIDH为NADP-依赖型单体IDH.本工作为进一步探索单体IDH的结构与功能以及单体IDH与同源二聚体IDH的进化关系奠定了基础.

  19. 21 CFR 862.1670 - Sorbitol dehydrogenase test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Sorbitol dehydrogenase test system. 862.1670... Systems § 862.1670 Sorbitol dehydrogenase test system. (a) Identification. A sorbitol dehydrogenase test system is a device intended to measure the activity of the enzyme sorbitol dehydrogenase in...

  20. Microbial alcohol dehydrogenases: identification, characterization and engineering

    NARCIS (Netherlands)

    Machielsen, M.P.

    2007-01-01

    Keywords: alcohol dehydrogenase, laboratory evolution, rational protein engineering, Pyrococcus furiosus, biocatalysis, characterization, computational design, thermostability.   Alcohol dehydrogeases (ADHs) catalyze the interconversion of alcohols, aldehydes and ketones. They display a wide variety

  1. Genetics Home Reference: dihydropyrimidine dehydrogenase deficiency

    Science.gov (United States)

    ... of the skin on the palms and soles (hand-foot syndrome); shortness of breath; and hair loss may also ... dehydrogenase deficiency , with its early-onset neurological symptoms, is a rare disorder. Its prevalence is ...

  2. Isocitrate dehydrogenase mutations in gliomas.

    Science.gov (United States)

    Waitkus, Matthew S; Diplas, Bill H; Yan, Hai

    2016-01-01

    Over the last decade, extraordinary progress has been made in elucidating the underlying genetic causes of gliomas. In 2008, our understanding of glioma genetics was revolutionized when mutations in isocitrate dehydrogenase 1 and 2 (IDH1/2) were identified in the vast majority of progressive gliomas and secondary glioblastomas (GBMs). IDH enzymes normally catalyze the decarboxylation of isocitrate to generate α-ketoglutarate (αKG), but recurrent mutations at Arg(132) of IDH1 and Arg(172) of IDH2 confer a neomorphic enzyme activity that catalyzes reduction of αKG into the putative oncometabolite D-2-hydroxyglutate (D2HG). D2HG inhibits αKG-dependent dioxygenases and is thought to create a cellular state permissive to malignant transformation by altering cellular epigenetics and blocking normal differentiation processes. Herein, we discuss the relevant literature on mechanistic studies of IDH1/2 mutations in gliomas, and we review the potential impact of IDH1/2 mutations on molecular classification and glioma therapy.

  3. Gene cloning and mRNA expression of glutamate dehydrogenase in the liver, brain and intestine of the swamp eel, Monopterus albus, exposed to freshwater, terrestrial conditions, environmental ammonia or salinity stress

    OpenAIRE

    C Y Toh; S F Chew; Ip, Alex Y.K.

    2011-01-01

    The swamp eel, Monopterus albus, is an obligatory air-breathing teleost which can survive long period of emersion, has high environmental and tissue ammonia tolerance, and acclimate from fresh to brackish water. This study was undertaken to clone and sequence gdh expressed in the liver, intestine and brain of M. albus, to verify whether more than one form of gdh were expressed, and to examine the gdh mRNA expressions in these three organs in fish exposed to various adverse conditions using qu...

  4. Changes in short-chain acyl-coA dehydrogenase during rat cardiac development and stress

    OpenAIRE

    Huang, Jinxian; Xu, Lipeng; Huang, Qiuju; Luo, Jiani; Liu, Peiqing; Chen, Shaorui; Yuan, Xi; Lu, Yao; Wang, Ping; Zhou, Sigui

    2015-01-01

    This study was designed to investigate the expression of short-chain acyl-CoA dehydrogenase (SCAD), a key enzyme of fatty acid β-oxidation, during rat heart development and the difference of SCAD between pathological and physiological cardiac hypertrophy. The expression of SCAD was lowest in the foetal and neonatal heart, which had time-dependent increase during normal heart development. In contrast, a significant decrease in SCAD expression was observed in different ages of spontaneously hyp...

  5. Isolation and biochemical characterization of a glucose dehydrogenase from a hay infusion metagenome.

    Science.gov (United States)

    Basner, Alexander; Antranikian, Garabed

    2014-01-01

    Glucose hydrolyzing enzymes are essential to determine blood glucose level. A high-throughput screening approach was established to identify NAD(P)-dependent glucose dehydrogenases for the application in test stripes and the respective blood glucose meters. In the current report a glucose hydrolyzing enzyme, derived from a metagenomic library by expressing recombinant DNA fragments isolated from hay infusion, was characterized. The recombinant clone showing activity on glucose as substrate exhibited an open reading frame of 987 bp encoding for a peptide of 328 amino acids. The isolated enzyme showed typical sequence motifs of short-chain-dehydrogenases using NAD(P) as a co-factor and had a sequence similarity between 33 and 35% to characterized glucose dehydrogenases from different Bacillus species. The identified glucose dehydrogenase gene was expressed in E. coli, purified and subsequently characterized. The enzyme, belonging to the superfamily of short-chain dehydrogenases, shows a broad substrate range with a high affinity to glucose, xylose and glucose-6-phosphate. Due to its ability to be strongly associated with its cofactor NAD(P), the enzyme is able to directly transfer electrons from glucose oxidation to external electron acceptors by regenerating the cofactor while being still associated to the protein.

  6. Isolation and biochemical characterization of a glucose dehydrogenase from a hay infusion metagenome.

    Directory of Open Access Journals (Sweden)

    Alexander Basner

    Full Text Available Glucose hydrolyzing enzymes are essential to determine blood glucose level. A high-throughput screening approach was established to identify NAD(P-dependent glucose dehydrogenases for the application in test stripes and the respective blood glucose meters. In the current report a glucose hydrolyzing enzyme, derived from a metagenomic library by expressing recombinant DNA fragments isolated from hay infusion, was characterized. The recombinant clone showing activity on glucose as substrate exhibited an open reading frame of 987 bp encoding for a peptide of 328 amino acids. The isolated enzyme showed typical sequence motifs of short-chain-dehydrogenases using NAD(P as a co-factor and had a sequence similarity between 33 and 35% to characterized glucose dehydrogenases from different Bacillus species. The identified glucose dehydrogenase gene was expressed in E. coli, purified and subsequently characterized. The enzyme, belonging to the superfamily of short-chain dehydrogenases, shows a broad substrate range with a high affinity to glucose, xylose and glucose-6-phosphate. Due to its ability to be strongly associated with its cofactor NAD(P, the enzyme is able to directly transfer electrons from glucose oxidation to external electron acceptors by regenerating the cofactor while being still associated to the protein.

  7. Gene cloning and mRNA expression of glutamate dehydrogenase in the liver, brain and intestine of the swamp eel, Monopterus albus, exposed to freshwater, terrestrial conditions, environmental ammonia or salinity stress

    Directory of Open Access Journals (Sweden)

    C Y Toh

    2011-12-01

    Full Text Available The swamp eel, Monopterus albus, is an obligatory air-breathing teleost which can survive long period of emersion, has high environmental and tissue ammonia tolerance, and acclimate from fresh to brackish water. This study was undertaken to clone and sequence gdh expressed in the liver, intestine and brain of M. albus, to verify whether more than one form of gdh were expressed, and to examine the gdh mRNA expressions in these three organs in fish exposed to various adverse conditions using quantitative real-time PCR. Only one gdh gene sequence, consisted of a 133 bp 5’ UTR, a CDS region spanning 1629 bp and a 3’ UTR of approximately 717 bp, was obtained from the liver, intestine and brain of M. albus. The translated Gdh amino acid sequence from the liver of M. albus had 542 residues and was confirmed to be Gdh1a. It had sequence identity of >90% with Oncorhynchus mykiss Gdh1a, Salmo salar Gdh1a1, Bostrychus sinensis Gdh1a and Tribolodon hakonensis Gdh1a, and formed a monophyletic clade with B. sinensis Gdh1a, Tetraodon nigroviridis Gdh1a, Chaenocephalus aceratus Gdh1a, Salmo salar Gdh1a1 and Gdh1a2 and O. mykiss Gdh1a. An increase in mRNA expression of gdh1a could be essential for increased glutamate production in support of increases in glutamine synthesis under certain environmental condition. Indeed, exposure of M. albus to 1 day of terrestrial conditions or 75 mmol l-1 NH4Cl, but not brackish water, resulted in a significant increase in gdh1a mRNA expression in the liver. However, exposure to brackish water, but not terrestrial conditions or 75 mmol l-1 NH4Cl, lead to a significant increase in the intestinal mRNA expression of gdh1a. By contrast, all the three experimental conditions had no significant effects on the mRNA expression of gdh1a in the brain of M. albus. Our results indicate for the first time that gdh mRNA expression was differentially up-regulated in the liver and intestine of M. albus, in responses to ammonia toxicity and

  8. 杜氏盐藻甘油醛-3-磷酸脱氢酶基因启动子驱动氯霉素乙酰转移酶基因的表达及其活性检测%Expression and activity detection of chloramphenicol acetyltransferase gene driven by the glyceraldehyde-3-phosphate dehydrogenase gene of Dunaliella salina

    Institute of Scientific and Technical Information of China (English)

    张小毅; 刘巨源; 邱乐乐; 贾岩龙

    2012-01-01

    目的 为建立稳定高效的盐藻生物反应器寻找合适的内源性启动子驱动表达外源基因.方法 克隆鉴定了盐藻甘油醛-3-磷酸脱氢酶(GAPDH)基因5 ′上游区序列并成功构建由盐藻GAPDH基因启动子驱动的氯霉素乙酰转移酶(CAT)基因表达载体pUC-Gcat.利用构建的表达载体电击转化盐藻并在含有氯霉素的培养基中筛选转化藻株.随机挑选稳定转化的盐藻藻株进行CAT酶联免疫吸附测定分析.结果 获得3株稳定转化的盐藻藻株.聚合酶链式反应鉴定和CAT酶联免疫吸附测定分析结果表明,CAT基因已整合到了转化的盐藻基因组中.结论 本研究所克隆的内源性盐藻GAPDH基因启动子能够驱动CAT基因在盐藻中表达.%Objective To explore expression of foreign gene driven by a strong endogenous promoter in order to construct stable and high-performance bioreactors in Dunaliella salina. Methods In the present study, the upstream sequence of glyceraldehyde phosphate dehydrogenase of Dunaliella salina was cloned and identificated. Using electroporation, the alga was transformed with a plasmid pUC-Ccat containing giyceraldehyde-3-phosphate dehydrogenase ( GAPDH) gene promoter of Du-naliella salina and chloramphenicol acetyltransferase ( CAT) gene as a seletable gene. Using the expression vector, the Dunaliella salina cell was translated and the transformational strain was screened in nutrient medium containing chloramphenicol. The stable transformational strain was selected randomly to undertake CAT enzyme linked immunosorbent assay (ELISA). Results Three stable transformational strain were obtained. The results of polymerase chain reaction and CAT ELISA indicated that the CAT gene had been transferred to the alga. Conclusion The results of this paper suggest that the GAPDH gene promoter can work for genetic transformation of Dunaliella salina.

  9. Crystallization and preliminary X-ray diffraction of malate dehydrogenase from Plasmodium falciparum

    NARCIS (Netherlands)

    Wrenger, Carsten; Mueller, Ingrid B.; Butzloff, Sabine; Jordanova, Rositsa; Lunev, Sergey; Groves, Matthew R.

    2012-01-01

    The expression, purification, crystallization and preliminary X-ray diffraction characterization of malate dehydrogenase (MDH) from the malarial parasite Plasmodium falciparum (PfMDH) are reported. In order to gain a deeper understanding of the function and role of PfMDH, the protein was purified to

  10. Watermelon glyoxysomal malate dehydrogenase is sorted to peroxisomes of the methylotrophic yeast, Hansenula polymorpha

    NARCIS (Netherlands)

    Klei, I.J. van der; Faber, K.N.; Keizer-Gunnink, I.; Gietl, C.; Harder, W.; Veenhuis, M.

    1993-01-01

    We have studied the fate of the watermelon (Citrullus vulgaris Schrad.) glyoxysomal enzyme, malate dehydrogenase (gMDH), after synthesis in the methylotrophic yeast, Hansenula polymorpha. The gene encoding the precursor form of gMDH (pre-gMDH) was cloned in an H. polymorpha expression vector downstr

  11. 棉花 GhMDH 基因的克隆及其蛋白诱导和酶活性分析%Cloning and Protein Expression of Malate Dehydrogenase Gene of Gossypium hirsuturm L.and Its Enzyme Activity Analysis

    Institute of Scientific and Technical Information of China (English)

    李青; 张宁; 司怀军; 吴家和

    2013-01-01

    According to the salt stress-related EST sequences of Gossypium hirsuturm L.,a malate dehydrogen-ase ( MDH) gene was isolated by the 3′,5′-RACE technology ,named GhMDH.The full-length cDNA of GhMDH is 1 130 bp,containing a 1 014 bp ORF which encodes 338 amino acids.The relative molecular weight of GhMDH protein is 35.495 kDa,and its isoelectric point (pI) is 8.94.The GhMDH ORF had been subcloned into pET23b vector for generating a His-tag fusion recombinant protein .The inducible conditions of recombinant protein expres-sion was optimized ,including IPTG contend ,temperature and time .The results showed that the target protein was packaged in inclusion body expressed under 37 ℃,1 mmol/L IPTG and 4 hrs induction conditions .The soluble re-combinant protein can only receive in less than 28 ℃and 12 hrs induction .The urea denatured protein from inclu-sion body had been purified by Ni +column .The purified protein was then renatured through ladder contend dialysis from high to low.The recombinant protein ,GhMDH,exhibited high malate dehydrogenase activates via enzymatic as-say .The results is pivotal to investigate GhMDH fuction in cell redox homeostasis and biotic and abiotic stress resist -ance in cotton .%分析棉花盐胁迫相关的EST文库,设计特异性引物,利用RACE技术从棉花中克隆出苹果酸脱氢酶( Malate dehydrogenase ,MDH)基因,命名为GhMDH。基因全长1130 bp,最大开放阅读框1014 bp,编码338个氨基酸,分子量为35.495 kDa,等电点pI=8.94。将该基因编码区插入到原核表达载体pET23b中,获得pET23b-GhMDH重组载体。利用IPTG诱导表达目标蛋白,发现通常条件下获得的重组蛋白以包涵体的形式存在。对诱导时间、IPTG浓度和温度等条件进行优化,结果表明,除了在28℃低温以下诱导的蛋白有少量为可溶,其他条件诱导的蛋白均以包涵体形式存在。为了得到足够的重组蛋白,对GhMDH包涵体蛋

  12. In Silico Analysis of Arabidopsis thaliana Peroxisomal 6-Phosphogluconate Dehydrogenase

    Directory of Open Access Journals (Sweden)

    Álvaro D. Fernández-Fernández

    2016-01-01

    Full Text Available NADPH, whose regeneration is critical for reductive biosynthesis and detoxification pathways, is an essential component in cell redox homeostasis. Peroxisomes are subcellular organelles with a complex biochemical machinery involved in signaling and stress processes by molecules such as hydrogen peroxide (H2O2 and nitric oxide (NO. NADPH is required by several peroxisomal enzymes involved in β-oxidation, NO, and glutathione (GSH generation. Plants have various NADPH-generating dehydrogenases, one of which is 6-phosphogluconate dehydrogenase (6PGDH. Arabidopsis contains three 6PGDH genes that probably are encoded for cytosolic, chloroplastic/mitochondrial, and peroxisomal isozymes, although their specific functions remain largely unknown. This study focuses on the in silico analysis of the biochemical characteristics and gene expression of peroxisomal 6PGDH (p6PGDH with the aim of understanding its potential function in the peroxisomal NADPH-recycling system. The data show that a group of plant 6PGDHs contains an archetypal type 1 peroxisomal targeting signal (PTS, while in silico gene expression analysis using affymetrix microarray data suggests that Arabidopsis p6PGDH appears to be mainly involved in xenobiotic response, growth, and developmental processes.

  13. 大肠杆菌葡萄糖脱氢酶基因的克隆与原核表达%Cloning and prokaryotic expression of glucose dehydrogenase from Escherichia coli

    Institute of Scientific and Technical Information of China (English)

    韩增叶; 孙继国; 葛喜珍; 田平芳

    2012-01-01

    克隆出大肠杆菌编码葡萄糖脱氢酶(PQQGDH)的gcd基因,构建了诱导型表达载体pET28a-gcd,转化大肠杆菌E.coli BL21后获得阳性克隆菌株BL21/pET28 a-gcd.IPTG诱导后,经SDS-PAGE分析表明,该工程菌PQQG-DH的表达量约为对照菌的18倍,约为18.2 mg/L,实现了高表达.此外,研究发现添加MgCl2能提高PQQGDH的表达量.%The gcd gene-encoding pyrroloquinoline quinine ( PQQGDH) has been cloned using the polymeraae chain reaction (PCR) from E. Coli BL21, and an inducible expression vector pET28a-gcd was constructed and transformed into E. Coli BL21. Sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) analysis showed a high expression of PQQGDH upon isopropyl β-D-1 -thiogalactopyranoside (IPTG) induction (18.2 mg/ L) , corresponding to a 18-fold increase compared with that in control strain. Addition of MgC12 further enhanced the expression of PQQGDH.

  14. Detection of Recombinant Protein Expression of Formate Dehydrogenase in Single Living Escherichia Coli Cell by Laser Tweezers Raman Spectroscopy%单细胞激光拉曼光谱检测重组大肠杆菌细胞表达甲酸脱氢酶

    Institute of Scientific and Technical Information of China (English)

    卢明倩; 董蓉; 温顺华; 张韦; 王巧贞; 黄庶识; 陈丽梅

    2012-01-01

    甲酸脱氢酶(FDH,EC1.2.1.2)在工业生产中有重要的应用价值,工业上应用的FDH可以通过构建高水平表达重组FDH蛋白的基因工程菌生产,用分子生物学的方法检测重组蛋白的高效表达和积累操作繁杂,耗时耗力且需要破碎细胞.为了寻找一种简单快速,不需破碎细胞,且能实时检测FDH重组蛋白在基因工程菌中表达情况的方法,本研究应用单细胞激光拉曼光谱分析技术(LTRS),研究IPTG诱导不同时间后甲酸脱氢酶重组蛋白(FDH)在大肠杆菌细胞中的表达水平.结果表明,FDH的特征峰1004,1355,1455和1667 cm-1随着IPTG诱导时间的延长而增强,说明在诱导培养过程中FDH重组蛋白在重组大肠杆菌细胞中表达并积累,这4个峰强的增加值所反映的FDH表达量与SDS-PAGE电泳分析结果一致.实验结果证明,LTRS是快速有效检测单个大肠杆菌活细胞体内重组FDH实时表达的一种非入侵方法.%The detection of the expression of formate dehydrogenase (FDH) recombination proteins in E. coli by molecular methods is time-consuming and hard-working and needs to destruct E. coli cells. To explore a simple and rapid method without cell destruction to detect the real-time expression of FDH recombination proteins in E. coli, Laser Tweezers Raman spectroscopy (LTRS) was used to investigate the recombinant protein expression of formate dehydrogenase (FDH) in the single living E. coli cell at different culture times following the induction with isopropyl thiogalactoside (IPTG). The result showed that the characteristic peaks corresponding to the recombinant FDH protein were gradually enhanced with an in increase in IPTG induction time, indicating the expression and the accumulation of FDH protein in recombinant E. coli cells. This result is consistent with that obtained by the analysis of sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). This evidence confirms that LTRS is an effectively method

  15. (2R,3R)-丁二醇脱氢酶的体外重组表达%Recombinant Expression of(2R,3R)-Butanediol Dehydrogenase in Vitro

    Institute of Scientific and Technical Information of China (English)

    罗雅婧; 严陶陶

    2015-01-01

    ObjectiveTo establish how 2,3-BDH possesse differential stereo specificities.Methods The gene of(2R,3R)-BDH amplified from the genome of Bacillus subtilis,and was inserted into pMD18-T vector for sequencing. The constructed recombinant expression vector was sequenced, and the result of this experiment was compared with the known sequence to construct evolutionary tree.ResultsSoluble expression of the recombinant plasmid was obtained in the recombinant bacteria.Conclusion (2R,3R)-BDH was obtained by induced expression in recombinant bacteria.%目的:明确2,3-丁二醇脱氢酶(2,3-BDH)如何具有不同的立体定向性。方法从枯草芽孢杆菌中克隆出(2R,3R)-丁二醇脱氢酶基因,将克隆的目的基因导入pMD18-T载体中,构建的重组质粒经测序后,将本实验序列和已发表序列进行比对分析,构建进化树。结果重组质粒可在重组菌中获得可溶性表达。结论利用重组菌株诱导表达获得了(2R,3R)-丁二醇脱氢酶。

  16. 日本结缕草ZjADH基因的克隆及表达分析%Cloning and Expression of an Alcohol Dehydrogenase Gene (Zj ADH)from Zoysia j aponica

    Institute of Scientific and Technical Information of China (English)

    滕珂; 李俊; 张兰; 郭蔚尔; 许立新; 晁跃辉

    2016-01-01

    采用 RACE 技术从日本结缕草中克隆出1个乙醇脱氢酶基因,命名为 Zj ADH (GenBank 登录号为KT596065)。Zj ADH 与甘蔗、美洲蒺藜草和沟叶结缕草等 ADH 基因同源性均在90%以上,进化分析表明其与沟叶结缕草亲缘关系最近。亚细胞定位结果显示,Zj ADH 定位于细胞质。实时荧光定量分析结果表明,Zj ADH 在日本结缕草根中表达量最高,Zj ADH 可响应 ABA、MeJA 和 SA 的诱导,在低温、干旱和高盐胁迫中发挥重要作用。%The AD H gene,Zj AD H ,was isolated from Zoysia j aponica by RACE method and then submitted to the GenBank (Accession number KT596065 ). Zj AD H shared a high level of similarity (more than 90% homology)with other AD H genes in Saccharum hybrid ,Cenchrus americanus and Zoy-sia matrella. Phylogenetic analysis showed that ZjADHis was the closest to ZmADH. Subcellular locali-zation of ZjADH was performed by Agrobacterium-mediated transient expression assay in N. benthami-ana. The results demonstrated that ZjADHis localized in the cytoplasm. Quantitative real time PCR was carried out to investigate the expression pattern of Zj AD H. The expression level of Zj AD H was much higher in root,and could be strongly induced by cold,drought or NaCl stresses. Exogenous ABA,MeJA or SA treatment could also up-regulate the expression of Zj AD H as well. Taken together,Zj AD H is a valuable gene in the study of abiotic stresses tolerance of Zoysia j aponica. This study paves the way to further study the Zj AD H in Zoysia j aponica.

  17. Serum lactic dehydrogenase isoenzymes and serum hydroxy butyric dehydrogenase in myocardial infarction

    Directory of Open Access Journals (Sweden)

    Kanekar D

    1979-01-01

    Full Text Available Total serum lactate dehydrogenase activity in cases of myocar-dial infarct is difficult to interpret as abnormal values can occur in diseases of liver, kidney and skeletal muscle. The estimation of its isoenzymes is of better diagnostic help because of its tissue specificity. Serum LDH isoenzymes were studied in patients o f myocardial infarction and results are quantitated by densitometry. As LDH 1 represents serum hydroxybutyric dehydrogenase when 2-oxylbutyrate is used as substrate, serum hydroxybutyric dehydro-genase was also estimated in above patients. Greater specificity in diagnosis is achieved with SHBDH because of its myocardial nature and lower incidence of false positive results.

  18. Yeast surface display of dehydrogenases in microbial fuel-cells.

    Science.gov (United States)

    Gal, Idan; Schlesinger, Orr; Amir, Liron; Alfonta, Lital

    2016-12-01

    Two dehydrogenases, cellobiose dehydrogenase from Corynascus thermophilus and pyranose dehydrogenase from Agaricus meleagris, were displayed for the first time on the surface of Saccharomyces cerevisiae using the yeast surface display system. Surface displayed dehydrogenases were used in a microbial fuel cell and generated high power outputs. Surface displayed cellobiose dehydrogenase has demonstrated a midpoint potential of -28mV (vs. Ag/AgCl) at pH=6.5 and was used in a mediator-less anode compartment of a microbial fuel cell producing a power output of 3.3μWcm(-2) using lactose as fuel. Surface-displayed pyranose dehydrogenase was used in a microbial fuel cell and generated high power outputs using different substrates, the highest power output that was achieved was 3.9μWcm(-2) using d-xylose. These results demonstrate that surface displayed cellobiose dehydrogenase and pyranose dehydrogenase may successfully be used in microbial bioelectrochemical systems.

  19. Alcohol dehydrogenase – physiological and diagnostic Importance

    Directory of Open Access Journals (Sweden)

    Magdalena Łaniewska-Dunaj

    2013-08-01

    Full Text Available Alcohol dehydrogenase (ADH is a polymorphic enzyme, existing in multiple isoenzymes divided into several classes and localized in different organs. ADH plays a significant role in the metabolism of many biologically important substances, catalyzing the oxidation or reduction of a wide spectrum of specific substrates. The best characterized function of ADH is protection against excess of ethanol and some other exogenous xenobiotics and products of lipid peroxidation. The isoenzymes of alcohol dehydrogenase also participate in the metabolism of retinol and serotonin. The total alcohol dehydrogenase activity is significantly higher in cancer tissues than in healthy organs (e.g. liver, stomach, colorectum. The changes in activity of particular ADH isoenzymes in the sera of patients with different cancers (especially of the digestive system seem to be caused by release of these isoenzymes from cancer cells, and may play a potential role as markers of this cancer. The particular isoenzymes of ADH present in the serum may indicate the cancer localization. Alcohol dehydrogenase may also be useful for diagnostics of non-cancerous liver diseases (e.g. viral hepatitis, non-alcoholic cirrhosis.

  20. Optimization of Adsorptive Immobilization of Alcohol Dehydrogenases

    NARCIS (Netherlands)

    Trivedi, Archana; Heinemann, Matthias; Spiess, Antje C.; Daussmann, Thomas; Büchs, Jochen

    2005-01-01

    In this work, a systematic examination of various parameters of adsorptive immobilization of alcohol dehydrogenases (ADHs) on solid support is performed and the impact of these parameters on immobilization efficiency is studied. Depending on the source of the enzymes, these parameters differently in

  1. Engineering of pyranose dehydrogenase for increased oxygen reactivity.

    Directory of Open Access Journals (Sweden)

    Iris Krondorfer

    Full Text Available Pyranose dehydrogenase (PDH, a member of the GMC family of flavoproteins, shows a very broad sugar substrate specificity but is limited to a narrow range of electron acceptors and reacts extremely slowly with dioxygen as acceptor. The use of substituted quinones or (organometals as electron acceptors is undesirable for many production processes, especially of food ingredients. To improve the oxygen reactivity, site-saturation mutagenesis libraries of twelve amino acids around the active site of Agaricus meleagris PDH were expressed in Saccharomyces cerevisiae. We established high-throughput screening assays for oxygen reactivity and standard dehydrogenase activity using an indirect Amplex Red/horseradish peroxidase and a DCIP/D-glucose based approach. The low number of active clones confirmed the catalytic role of H512 and H556. Only one position was found to display increased oxygen reactivity. Histidine 103, carrying the covalently linked FAD cofactor in the wild-type, was substituted by tyrosine, phenylalanine, tryptophan and methionine. Variant H103Y was produced in Pichia pastoris and characterized and revealed a five-fold increase of the oxygen reactivity.

  2. Expression

    Directory of Open Access Journals (Sweden)

    Wang-Xia Wang

    2014-02-01

    Full Text Available The miR-15/107 family comprises a group of 10 paralogous microRNAs (miRNAs, sharing a 5′ AGCAGC sequence. These miRNAs have overlapping targets. In order to characterize the expression of miR-15/107 family miRNAs, we employed customized TaqMan Low-Density micro-fluid PCR-array to investigate the expression of miR-15/107 family members, and other selected miRNAs, in 11 human tissues obtained at autopsy including the cerebral cortex, frontal cortex, primary visual cortex, thalamus, heart, lung, liver, kidney, spleen, stomach and skeletal muscle. miR-103, miR-195 and miR-497 were expressed at similar levels across various tissues, whereas miR-107 is enriched in brain samples. We also examined the expression patterns of evolutionarily conserved miR-15/107 miRNAs in three distinct primary rat brain cell preparations (enriched for cortical neurons, astrocytes and microglia, respectively. In primary cultures of rat brain cells, several members of the miR-15/107 family are enriched in neurons compared to other cell types in the central nervous system (CNS. In addition to mature miRNAs, we also examined the expression of precursors (pri-miRNAs. Our data suggested a generally poor correlation between the expression of mature miRNAs and their precursors. In summary, we provide a detailed study of the tissue and cell type-specific expression profile of this highly expressed and phylogenetically conserved family of miRNA genes.

  3. Increasing anaerobic acetate consumption and ethanol yields in Saccharomyces cerevisiae with NADPH-specific alcohol dehydrogenase.

    Science.gov (United States)

    Henningsen, Brooks M; Hon, Shuen; Covalla, Sean F; Sonu, Carolina; Argyros, D Aaron; Barrett, Trisha F; Wiswall, Erin; Froehlich, Allan C; Zelle, Rintze M

    2015-12-01

    Saccharomyces cerevisiae has recently been engineered to use acetate, a primary inhibitor in lignocellulosic hydrolysates, as a cosubstrate during anaerobic ethanolic fermentation. However, the original metabolic pathway devised to convert acetate to ethanol uses NADH-specific acetylating acetaldehyde dehydrogenase and alcohol dehydrogenase and quickly becomes constrained by limited NADH availability, even when glycerol formation is abolished. We present alcohol dehydrogenase as a novel target for anaerobic redox engineering of S. cerevisiae. Introduction of an NADPH-specific alcohol dehydrogenase (NADPH-ADH) not only reduces the NADH demand of the acetate-to-ethanol pathway but also allows the cell to effectively exchange NADPH for NADH during sugar fermentation. Unlike NADH, NADPH can be freely generated under anoxic conditions, via the oxidative pentose phosphate pathway. We show that an industrial bioethanol strain engineered with the original pathway (expressing acetylating acetaldehyde dehydrogenase from Bifidobacterium adolescentis and with deletions of glycerol-3-phosphate dehydrogenase genes GPD1 and GPD2) consumed 1.9 g liter(-1) acetate during fermentation of 114 g liter(-1) glucose. Combined with a decrease in glycerol production from 4.0 to 0.1 g liter(-1), this increased the ethanol yield by 4% over that for the wild type. We provide evidence that acetate consumption in this strain is indeed limited by NADH availability. By introducing an NADPH-ADH from Entamoeba histolytica and with overexpression of ACS2 and ZWF1, we increased acetate consumption to 5.3 g liter(-1) and raised the ethanol yield to 7% above the wild-type level.

  4. Isolation and Expression Analysis of Plastidic Glucose-6-phosphate Dehydrogenase Gene from Rice (Oryza sativa L.)%水稻质体葡萄糖-6-磷酸脱氢酶基因的克隆与表达研究

    Institute of Scientific and Technical Information of China (English)

    侯夫云; 黄骥; 陆驹飞; 王州飞; 张红生

    2006-01-01

    Glucose-6-phosphate dehydrogenase is a rate-limiting enzyme of pentose phosphate pathway, existing in cytosolic and plastidic compartments of higher plants. A novel gene encoding plastidic glucose-6-phosphate dehydrogenase was isolated from rice (Oryza sativa L.) and designated OsG6PDH2 in this article. Through semiquantitative RT-PCR approach it was found that OsG6PDH2 mRNA was weakly expressed in rice leaves, stems, immature spikes or flowered spikes, and a little higher in roots.However, the expression of OsG6PDH2 in rice seedlings was significantly induced by dark treatment. The complete opening reading frame (ORF) of OsG6PDH2 was inserted into pET30a (+), and expressed in Escherichia coli strain BL21 (DE3). The enzyme activity assay of transformed bacterial cells indicated that OsG6PDH2 encoding product had a typical function of glucose-6-phosphate dehydrogenase.%戊糖磷酸途径是高等植物中重要的代谢途径,主要生理功能是产生NADPH以及供核酸代谢的磷酸戊糖.葡萄糖-6-磷酸脱氢酶(G6PDH)是戊糖磷酸途径的关键酶,广泛存在于高等植物细胞的细胞质和质体中.本研究首次从水稻(Oryzasativa L.)幼苗中分离了核编码的质体G6PDH基因OsG6PDH2,序列分析表明OsG6PDH2编码一个具有588个氨基酸残基的多肽,等电点为8.5,分子量66 kDa.OsG6PDH2的N端有1个70个氨基酸的信号肽,推测的裂解位点为Gly55和Val56,表明OsG6PDH2编码产物可能定位于质体.多序列比较的结果表明OsG6PDH2与拟南芥、烟草、马铃薯质体G6PDH的一致性分别达81%、87%、83%.进化关系说明水稻OsG6PDH2与拟南芥(AtG6PDH3)、马铃薯(StG6PDH1)处于高等植物P2型质体G6PDH分支上,暗示了OsG6PDH2可能是一个P2型的质体蛋白.Matinspector程序分析表明,OsG6PDH2在起始密码子上游含有一个bZIP转录因子识别位点、一个ABA应答元件、一个CRT/DRE元件和1个W-box元件.半定量RT-PCR分析表明,OsG6PDH2在水稻根、茎、叶和幼

  5. Physiological regulation of isocitrate dehydrogenase and the role of 2-oxoglutarate in Prochlorococcus sp. strain PCC 9511.

    Science.gov (United States)

    Domínguez-Martín, María Agustina; López-Lozano, Antonio; Diez, Jesús; Gómez-Baena, Guadalupe; Rangel-Zúñiga, Oriol Alberto; García-Fernández, José Manuel

    2014-01-01

    The enzyme isocitrate dehydrogenase (ICDH; EC 1.1.1.42) catalyzes the oxidative decarboxylation of isocitrate, to produce 2-oxoglutarate. The incompleteness of the tricarboxylic acids cycle in marine cyanobacteria confers a special importance to isocitrate dehydrogenase in the C/N balance, since 2-oxoglutarate can only be metabolized through the glutamine synthetase/glutamate synthase pathway. The physiological regulation of isocitrate dehydrogenase was studied in cultures of Prochlorococcus sp. strain PCC 9511, by measuring enzyme activity and concentration using the NADPH production assay and Western blotting, respectively. The enzyme activity showed little changes under nitrogen or phosphorus starvation, or upon addition of the inhibitors DCMU, DBMIB and MSX. Azaserine, an inhibitor of glutamate synthase, induced clear increases in the isocitrate dehydrogenase activity and icd gene expression after 24 h, and also in the 2-oxoglutarate concentration. Iron starvation had the most significant effect, inducing a complete loss of isocitrate dehydrogenase activity, possibly mediated by a process of oxidative inactivation, while its concentration was unaffected. Our results suggest that isocitrate dehydrogenase responds to changes in the intracellular concentration of 2-oxoglutarate and to the redox status of the cells in Prochlorococcus.

  6. Physiological regulation of isocitrate dehydrogenase and the role of 2-oxoglutarate in Prochlorococcus sp. strain PCC 9511.

    Directory of Open Access Journals (Sweden)

    María Agustina Domínguez-Martín

    Full Text Available The enzyme isocitrate dehydrogenase (ICDH; EC 1.1.1.42 catalyzes the oxidative decarboxylation of isocitrate, to produce 2-oxoglutarate. The incompleteness of the tricarboxylic acids cycle in marine cyanobacteria confers a special importance to isocitrate dehydrogenase in the C/N balance, since 2-oxoglutarate can only be metabolized through the glutamine synthetase/glutamate synthase pathway. The physiological regulation of isocitrate dehydrogenase was studied in cultures of Prochlorococcus sp. strain PCC 9511, by measuring enzyme activity and concentration using the NADPH production assay and Western blotting, respectively. The enzyme activity showed little changes under nitrogen or phosphorus starvation, or upon addition of the inhibitors DCMU, DBMIB and MSX. Azaserine, an inhibitor of glutamate synthase, induced clear increases in the isocitrate dehydrogenase activity and icd gene expression after 24 h, and also in the 2-oxoglutarate concentration. Iron starvation had the most significant effect, inducing a complete loss of isocitrate dehydrogenase activity, possibly mediated by a process of oxidative inactivation, while its concentration was unaffected. Our results suggest that isocitrate dehydrogenase responds to changes in the intracellular concentration of 2-oxoglutarate and to the redox status of the cells in Prochlorococcus.

  7. Involvement of snapdragon benzaldehyde dehydrogenase in benzoic acid biosynthesis.

    Science.gov (United States)

    Long, Michael C; Nagegowda, Dinesh A; Kaminaga, Yasuhisa; Ho, Kwok Ki; Kish, Christine M; Schnepp, Jennifer; Sherman, Debra; Weiner, Henry; Rhodes, David; Dudareva, Natalia

    2009-07-01

    Benzoic acid (BA) is an important building block in a wide spectrum of compounds varying from primary metabolites to secondary products. Benzoic acid biosynthesis from L-phenylalanine requires shortening of the propyl side chain by two carbons, which can occur via a beta-oxidative pathway or a non-beta-oxidative pathway, with benzaldehyde as a key intermediate. The non-beta-oxidative route requires benzaldehyde dehydrogenase (BALDH) to convert benzaldehyde to BA. Using a functional genomic approach, we identified an Antirrhinum majus (snapdragon) BALDH, which exhibits 40% identity to bacterial BALDH. Transcript profiling, biochemical characterization of the purified recombinant protein, molecular homology modeling, in vivo stable isotope labeling, and transient expression in petunia flowers reveal that BALDH is capable of oxidizing benzaldehyde to BA in vivo. GFP localization and immunogold labeling studies show that this biochemical step occurs in the mitochondria, raising a question about the role of subcellular compartmentalization in BA biosynthesis.

  8. Hybridizability of gamma-irradiated lactic dehydrogenase

    Energy Technology Data Exchange (ETDEWEB)

    Saito, M.

    1976-03-01

    The hybridizabilities of the gamma-irradiated chicken heart and pig muscle lactic dehydrogenases were estimated by hybridizing the irradiated enzymes with the unirradiated pig heart lactic dehydrogenase. The disc gel electrophoretic patterns of the inter- and intraspecific hybrids showed that the LDH activity of the pig heart isozyme band increased as a function of dose. This observation was analyzed upon the binomial redistribution pattern of the recombined subunits. The result shows that the hybridizabilities of both the chicken heart and pig muscle isozymes decreased along with the loss of catalytic activity and the release from substrate inhibition. The titration of free SH groups of the irradiated chicken isozyme suggested that the unfolding of the peptide chain destroyed the specific tertiary structure needed for the binding of subunits. (auth)

  9. Purification of arogenate dehydrogenase from Phenylobacterium immobile.

    Science.gov (United States)

    Mayer, E; Waldner-Sander, S; Keller, B; Keller, E; Lingens, F

    1985-01-07

    Phenylobacterium immobile, a bacterium which is able to degrade the herbicide chloridazon, utilizes for L-tyrosine synthesis arogenate as an obligatory intermediate which is converted in the final biosynthetic step by a dehydrogenase to tyrosine. This enzyme, the arogenate dehydrogenase, has been purified for the first time in a 5-step procedure to homogeneity as confirmed by electrophoresis. The Mr of the enzyme that consists of two identical subunits amounts to 69000 as established by gel electrophoresis after cross-linking the enzyme with dimethylsuberimidate. The Km values were 0.09 mM for arogenate and 0.02 mM for NAD+. The enzyme has a high specificity with respect to its substrate arogenate.

  10. Isocitrate dehydrogenase 1 and 2 mutations in cholangiocarcinoma.

    Science.gov (United States)

    Kipp, Benjamin R; Voss, Jesse S; Kerr, Sarah E; Barr Fritcher, Emily G; Graham, Rondell P; Zhang, Lizhi; Highsmith, W Edward; Zhang, Jun; Roberts, Lewis R; Gores, Gregory J; Halling, Kevin C

    2012-10-01

    Somatic mutations in isocitrate dehydrogenase 1 and 2 genes are common in gliomas and help stratify patients with brain cancer into histologic and molecular subtypes. However, these mutations are considered rare in other solid tumors. The aims of this study were to determine the frequency of isocitrate dehydrogenase 1 and 2 mutations in cholangiocarcinoma and to assess histopathologic differences between specimens with and without an isocitrate dehydrogenase mutation. We sequenced 94 formalin-fixed, paraffin-embedded cholangiocarcinoma (67 intrahepatic and 27 extrahepatic) assessing for isocitrate dehydrogenase 1 (codon 132) and isocitrate dehydrogenase 2 (codons 140 and 172) mutations. Multiple histopathologic characteristics were also evaluated and compared with isocitrate dehydrogenase 1/2 mutation status. Of the 94 evaluated specimens, 21 (22%) had a mutation including 14 isocitrate dehydrogenase 1 and 7 isocitrate dehydrogenase 2 mutations. Isocitrate dehydrogenase mutations were more frequently observed in intrahepatic cholangiocarcinoma than in extrahepatic cholangiocarcinoma (28% versus 7%, respectively; P = .030). The 14 isocitrate dehydrogenase 1 mutations were R132C (n = 9), R132S (n = 2), R132G (n = 2), and R132L (n = 1). The 7 isocitrate dehydrogenase 2 mutations were R172K (n = 5), R172M (n = 1), and R172G (n = 1). Isocitrate dehydrogenase mutations were more frequently observed in tumors with clear cell change (P < .001) and poorly differentiated histology (P = .012). The results of this study show for the first time that isocitrate dehydrogenase 1 and 2 genes are mutated in cholangiocarcinoma. The results of this study are encouraging because it identifies a new potential target for genotype-directed therapeutic trials and may represent a potential biomarker for earlier detection of cholangiocarcinoma in a subset of cases.

  11. Expression of isocitrate dehydrogenase 1 gene R132H and its diagnostic application in glioma%IDH1R132H在中枢神经系统胶质瘤中的表达及其鉴别诊断意义

    Institute of Scientific and Technical Information of China (English)

    朴月善; 卢德宏; 张晓娟; 汤国才; 杨虹

    2011-01-01

    Objective To investigate the immunohistochemical expression of isocitrate dehydrogenase 1 gene ( IDH1 ) R132H in glioma and its diagnostic utility. Methods Immunohistochemical study of IDH1R132H expression was performed on formalin-fixed paraffin-embedded tissue samples of 75 gliomas, including 33 cases of grade Ⅱ , 20 cases of grade Ⅲ and 22 cases of grade Ⅳ tumors. Six cases of pilocytic astrocytoma and 12 cases of gliosis were used as controls. Results Nineteen in 33 cases of grade Ⅱ (57.6%), 8 in 20 cases of grade Ⅲ (40. 0% ), 6 in 22 cases of grade Ⅳ (27. 3% ) showed positive cytoplasmic staining of IDH1R132H. Scattered invasive glioma cells at the tumor periphery also expressed IDH1R132H. Gliomas involving the frontal lobe showed more strong IDH1R132H staining. In contrast, none of the pilocytic astrocytomas and gliosis showed IDH1R132H staining. Moreover, the rate of p53 immunopositivities were 42. 4% ( 14/33 ) in grade Ⅱ , 65.0% (13/20) in grade Ⅲ and 77.3% (17/22) in grade Ⅳ gliomas. There were no statistic correlations between expression of IDH1R132H and p53.Conclusion IDH1R132H tends to express preferentially in low-grade gliomas, and it thus may serve as a valuable marker in distinguishing low grade gliomas from gliosis.%目的 探讨异柠檬酸盐脱氢酶1基因(isocitrate dehydrogenase 1 gene,IDH1)突变的表达产物IDH1R132H在人中枢神经系统胶质瘤中的表达及其在鉴别诊断中的意义.方法 应用免疫组织化学EnVision法检测不同级别胶质瘤75例(包括WHOⅡ级33例,Ⅲ级20例和Ⅳ级22例)与各种原因造成的胶质增生性脑组织中IDH1R132H的表达情况,并与p53的表达情况进行比较分析.结果 IDH1R132H在WHOⅡ级、Ⅲ级和Ⅳ级胶质瘤的表达阳性率分别为57.6%(19/33)、40.0%(8/20)和27.3%(6/22),差异有统计学意义(P=0.024).IDH1R132H的具体表达部位在胶质瘤细胞的胞质、突起以及部分细胞核.除肿瘤主体部分密集增生的肿瘤细胞

  12. Isolation and Biochemical Characterization of a Glucose Dehydrogenase from a Hay Infusion Metagenome

    OpenAIRE

    Alexander Basner; Garabed Antranikian

    2014-01-01

    Glucose hydrolyzing enzymes are essential to determine blood glucose level. A high-throughput screening approach was established to identify NAD(P)-dependent glucose dehydrogenases for the application in test stripes and the respective blood glucose meters. In the current report a glucose hydrolyzing enzyme, derived from a metagenomic library by expressing recombinant DNA fragments isolated from hay infusion, was characterized. The recombinant clone showing activity on glucose as substrate ex...

  13. Choline dehydrogenase interacts with SQSTM1/p62 to recruit LC3 and stimulate mitophagy

    OpenAIRE

    Park, Sungwoo; Choi, Seon-Guk; Yoo, Seung-Min; Son, Jin H.; Jung, Yong-Keun

    2014-01-01

    CHDH (choline dehydrogenase) is an enzyme catalyzing the dehydrogenation of choline to betaine aldehyde in mitochondria. Apart from this well-known activity, we report here a pivotal role of CHDH in mitophagy. Knockdown of CHDH expression impairs CCCP-induced mitophagy and PARK2/parkin-mediated clearance of mitochondria in mammalian cells, including HeLa cells and SN4741 dopaminergic neuronal cells. Conversely, overexpression of CHDH accelerates PARK2-mediated mitophagy. CHDH is found on both...

  14. Structure of a bacterial enzyme regulated by phosphorylation, isocitrate dehydrogenase.

    OpenAIRE

    1989-01-01

    The structure of isocitrate dehydrogenase [threo-DS-isocitrate: NADP+ oxidoreductase (decarboxylating), EC 1.1.1.42] from Escherichia coli has been solved and refined at 2.5 A resolution and is topologically different from that of any other dehydrogenase. This enzyme, a dimer of identical 416-residue subunits, is inactivated by phosphorylation at Ser-113, which lies at the edge of an interdomain pocket that also contains many residues conserved between isocitrate dehydrogenase and isopropylma...

  15. Malate dehydrogenase: a model for structure, evolution, and catalysis.

    OpenAIRE

    1994-01-01

    Malate dehydrogenases are widely distributed and alignment of the amino acid sequences show that the enzyme has diverged into 2 main phylogenetic groups. Multiple amino acid sequence alignments of malate dehydrogenases also show that there is a low degree of primary structural similarity, apart from in several positions crucial for nucleotide binding, catalysis, and the subunit interface. The 3-dimensional structures of several malate dehydrogenases are similar, despite their low amino acid s...

  16. 11beta-hydroxysteroid dehydrogenase type 1 in adipose tissue and prospective changes in body weight and insulin resistance

    DEFF Research Database (Denmark)

    Koska, Juraj; de Courten, Barbora; Wake, Deborah J

    2006-01-01

    Increased mRNA and activity levels of 11beta-hydroxysteroid dehydrogenase type 1 (11betaHSD1) in human adipose tissue (AT) are associated with obesity and insulin resistance. The aim of our study was to investigate whether 11betaHSD1 expression or activity in abdominal subcutaneous AT of non...

  17. 21 CFR 862.1500 - Malic dehydrogenase test system.

    Science.gov (United States)

    2010-04-01

    ... plasma. Malic dehydrogenase measurements are used in the diagnosis and treatment of muscle and liver diseases, myocardial infarctions, cancer, and blood disorders such as myelogenous (produced in the...

  18. Placental glucose dehydrogenase polymorphism in Koreans.

    Science.gov (United States)

    Kim, Y J; Paik, S G; Park, H Y

    1994-12-01

    The genetic polymorphism of placental glucose dehydrogenase (GDH) was investigated in 300 Korean placentae using horizontal starch gel electrophoresis. The allele frequencies for GDH1, GDH2 and GDH3 were 0.537, 0.440 and 0.005, respectively, which were similar to those in Japanese. We also observed an anodal allele which was similar to the GDH4 originally reported in Chinese populations at a low frequency of 0.015. An additional new cathodal allele (named GDH6) was observed in the present study with a very low frequency of 0.003.

  19. A rare disease-associated mutation in the medium-chain acyl-CoA dehydrogenase (MCAD) gene changes a conserved arginine, previously shown to be functionally essential in short-chain acyl-CoA dehydrogenase (SCAD)

    DEFF Research Database (Denmark)

    Andresen, B S; Bross, P; Jensen, T G

    1993-01-01

    157 mutation was verified in genomic DNA from the patient and her mother by a PCR-based assay. The mutation changes conserved arginine at position 28 (R28C) of the mature MCAD protein. The effect of the T157 mutation on MCAD protein was investigated by expression of mutant MCAD cDNA in COS-7 cells......-chain acyl-CoA dehydrogenase (SCAD) gene of a patient with SCAD deficiency, suggesting that the conserved arginine is crucial for formation of active enzyme in the straight-chain acyl-CoA dehydrogenases....

  20. Molecular determinants of the cofactor specificity of ribitol dehydrogenase, a short-chain dehydrogenase/reductase

    DEFF Research Database (Denmark)

    Moon, Hee-Jung; Tiwari, Manish Kumar; Singh, Ranjitha;

    2012-01-01

    Ribitol dehydrogenase from Zymomonas mobilis (ZmRDH) catalyzes the conversion of ribitol to d-ribulose and concomitantly reduces NAD(P)(+) to NAD(P)H. A systematic approach involving an initial sequence alignment-based residue screening, followed by a homology model-based screening and site...

  1. Activity and Expression Changes of Sorbitol Dehydrogenase in Developing Bagging 'Red Fuji' Apple Fruit%套袋‘红富士’苹果果实山梨醇脱氢酶的活性变化及其表达

    Institute of Scientific and Technical Information of China (English)

    袁梅; 叶成荣; 刘更森; 刘成连; 原永兵; 王永章

    2012-01-01

    以‘红富士’苹果为试材,通过酶活性测定和Western印迹技术,研究了套袋‘红富士’苹果果实山梨醇脱氢酶(SDH)的活性及其表达变化.结果表明,在整个发育过程中,套袋‘红富士’苹果果实的山梨醇含量及SDH活性的变化动态与对照果实基本一致.与对照相比,套袋苹果果实的SDH活性较低,山梨醇含量较高,由此表明套袋影响苹果果实山梨醇代谢.Western blotting结果显示,苹果果实SDH的亚基构成为40 kDa,随着苹果果实的发育,SDH的免疫信号强度逐渐增强.在同一取样时期,套袋苹果果实SDH的免疫信号强度与对照果实相比差异不显著,由此推断,SDH的活性变化可能存在翻译后水平上的调控.%The changes of sorbitol content, sorbitol dehydrogenase (SDH) activity and protein expression in bagging 'Red Fuji' apple fruit were studied through enzyme determination and Western blotting technique.The results showed that the sorbitol content and SDH activity in bagging ' Red Fuji' apple fruit almost had the same dynamic changes as control fruit during the whole developing period.Moreover, the relative lower SDH activity and higher sorbitol content were found in bagging apple fruit compared with control.Therefore, fruit bagging influenced sorbitol metabolism in some extent.On the other hand, Western blotting assay of SDH detected the presence of 40 kDa peptide and the intensity of immune signal in apple fruit increased gradually with fruit developing.However, few significant differences of immune signal existed in bagging and control fruit at the same sampling period.So it was concluded that the changes of SDH activity was regulated at post-translational level.

  2. Cloning and Expression of Pyruvate Dehydrogenase E 1-α Subunit Gene (pdha) in Mycoplasma ovipneumoniae and Its Immunologic Activity Evaluation%绵羊肺炎支原体(Mycoplasma ovipneumoniae)丙酮酸脱氢酶E1-α亚单位基因(pdha)的克隆、表达及其免疫学活性测定

    Institute of Scientific and Technical Information of China (English)

    许健; 储岳峰; 高鹏程; 赵萍; 贺英; 剡根强; 逯忠新

    2012-01-01

    丙酮酸脱氢酶α-亚单位(PDHA)在病原体丙酮酸脱氢酶的催化过程中发挥着重要作用.为表达绵羊肺炎支原体(Mycoplasma ovipneumoniae)PDHA蛋白并测定其免疫学活性,应用PCR方法扩增出绵羊肺炎支原体pdha基因并对其序列进行分析,将pdha基因中色氨酸密码子TGA优化为TGG后进行全基因合成,插入到pET32-a(+)载体上,构建了pET3 2-a(+ )-pdha重组质粒,将重组质粒转化到大肠杆菌(Escherichia coli)BL21中诱导表达PDHA蛋白,并通过免疫印迹及小鼠(Mus musculus)免疫试验对其免疫学活性进行测定.结果pdha基因全长1 125 bp,编码375 aa,(G+C)%为34.76%,第304~306位、379~381位、586~588位、592~594位、625~627位、811~813位、889~891位及964~966位TGA在支原体中编码色氨酸而不是作为终止密码子;基因序列比对及进化树分析显示,绵羊肺炎支原体pdha基因与10种支原体的pdha基因序列同源性为32.6%~85.3%,氨基酸序列同源性为39.3%~90.6%,基因序列和氨基酸序列均与猪肺炎支原体(M.hyopneumoniae)有同源性,分别为85.3%和90.6%;绵羊肺炎支原体pdha基因在33℃、IPTG 0.25 mmol/L诱导6h的表达条件下,表达量最高;重组的PDHA蛋白可与绵羊肺炎支原体高免血清具有免疫印迹条带,在免疫小鼠后血清抗体效价与对照组相比,均显著升高(P<0.05).本实验首次成功克隆表达了绵羊肺炎支原体pdha基因,并证明其重组PDHA蛋白具有较好的免疫学活性.为绵羊支原体肺炎基因工程疫苗及诊断研究提供候选靶标.%Pyruvate dehydrogenase El-a subunit (PDHA) plays an important role in the catalytic activity of pyruvate dehydrogenase of pathogens. In order to characterize the immunologic activity of the PDHA of Mycoplasma ovipneumoniae, we amplified and sequenced the pdha gene of M. Ovipneumoniae. After optimized with TGG instead of TGA for coding the amino acid of tryptophane, the pdha gene

  3. 内参基因GAPDH在3T3-L1脂肪细胞分化中的表达变化%Change of reference gene glyceraldehyde-3-phosphate dehydrogenase expression during 3T3-L1 adipocyte differentiation

    Institute of Scientific and Technical Information of China (English)

    张娟; 唐红菊; 王晓; 王宁; 邓儒元; 建方方; 刘赟; 李凤英; 周丽斌

    2012-01-01

    目的 观察甘油醛-3-磷酸脱氢酶(GAPDH)在3T3-L1脂肪细胞分化过程中表达水平是否存在变化,并与其他常用的内参基因相比较.方法 以实时定量PCR检测3T3-L1脂肪细胞分化0、1、3、5、7d几种不同常见内参基因的表达是否存在变化,并以Western印迹方法进行证实.结果 (1)内参基因GAPDH和转铁蛋白受体(TFRC)在脂肪细胞分化过程中基因表达水平逐渐明显升高,其中GAPDH mRNA 在脂肪细胞分化1、3、5、7d分别增加5.7、7.6、22.0和24.5倍(均P<0.01),β-actin、α-微管蛋白(α-tubulin)、肽酰脯氨酰异构酶(PIPA)和18S mRNA表达水平未见明显改变;采用实时定量PCR检测脂肪细胞分化的关键转录因子PPARγ2、CCAAT/增强结合蛋白(C/EBP)α和C/EBPβ的表达时,以GAPDH作内参明显低估他们的表达变化;GAPDH蛋白表达也随着脂肪细胞分化逐渐增加,β-actin、α-tubulin蛋白表达未见明显变化;(2)小檗碱明显抑制脂肪细胞分化过程中GAPDH mRNA和蛋白的表达,在脂肪细胞分化5、7d时GAPDH mRNA表达水平分别降低68.1%和66.3%(P<0.05或P<0.01),但小檗碱对其他内参基因的表达无明显改变.结论 GAPDH在3T3-L1脂肪细胞分化过程中表达增加,不适合作为内参.%Objective To observe the change of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) gene expression during 3T3-L1 adipocyte differentiation as well as other reference gene expressions.Methods The mRNA expressions of several common reference genes were detected by real time-PCR on day 0,1,3,5,and 7 of 3T3-L1 adipocyte differentiation.Western blot was used to confirm the protein expressions of three common reference genes.Results (1) GAPDH and transferrin receptor(TFRC) mRNA expressions were significantly increased during adipocyte differentiation.GAPDH mRNA level was increased by 5.7,7.6,22.0,and 24.5 folds on day 1,3,5,and 7 after induction of adipocyte differentiation,but no apparent changes of

  4. Role of Alanine Dehydrogenase of Mycobacterium tuberculosis during Recovery from Hypoxic Nonreplicating Persistence.

    Directory of Open Access Journals (Sweden)

    Michelle M Giffin

    Full Text Available Mycobacterium tuberculosis can maintain a nonreplicating persistent state in the host for decades, but must maintain the ability to efficiently reactivate and produce active disease to survive and spread in a population. Among the enzymes expressed during this dormancy is alanine dehydrogenase, which converts pyruvate to alanine, and glyoxylate to glycine concurrent with the oxidation of NADH to NAD. It is involved in the metabolic remodeling of M. tuberculosis through its possible interactions with both the glyoxylate and methylcitrate cycle. Both mRNA levels and enzymatic activities of isocitrate lyase, the first enzyme of the glyoxylate cycle, and alanine dehydrogenase increased during entry into nonreplicating persistence, while the gene and activity for the second enzyme of the glyoxylate cycle, malate synthase were not. This could suggest a shift in carbon flow away from the glyoxylate cycle and instead through alanine dehydrogenase. Expression of ald was also induced in vitro by other persistence-inducing stresses such as nitric oxide, and was expressed at high levels in vivo during the initial lung infection in mice. Enzyme activity was maintained during extended hypoxia even after transcription levels decreased. An ald knockout mutant of M. tuberculosis showed no reduction in anaerobic survival in vitro, but resulted in a significant lag in the resumption of growth after reoxygenation. During reactivation the ald mutant had an altered NADH/NAD ratio, and alanine dehydrogenase is proposed to maintain the optimal NADH/NAD ratio during anaerobiosis in preparation of eventual regrowth, and during the initial response during reoxygenation.

  5. Hexose-6-phosphate dehydrogenase contributes to skeletal muscle homeostasis independent of 11β-hydroxysteroid dehydrogenase type 1.

    LENUS (Irish Health Repository)

    Semjonous, Nina M

    2011-01-01

    Glucose-6-phosphate (G6P) metabolism by the enzyme hexose-6-phosphate dehydrogenase (H6PDH) within the sarcoplasmic reticulum lumen generates nicotinamide adenine dinucleotide phosphate (reduced) to provide the redox potential for the enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) to activate glucocorticoid (GC). H6PDH knockout (KO) mice have a switch in 11β-HSD1 activity, resulting in GC inactivation and hypothalamic-pituitary-adrenal axis activation. Importantly, H6PDHKO mice develop a type II fiber myopathy with abnormalities in glucose metabolism and activation of the unfolded protein response (UPR). GCs play important roles in muscle physiology, and therefore, we have examined the importance of 11β-HSD1 and GC metabolism in mediating aspects of the H6PDHKO myopathy. To achieve this, we examined 11β-HSD1\\/H6PDH double-KO (DKO) mice, in which 11β-HSD1 mediated GC inactivation is negated. In contrast to H6PDHKO mice, DKO mice GC metabolism and hypothalamic-pituitary-adrenal axis set point is similar to that observed in 11β-HSD1KO mice. Critically, in contrast to 11β-HSD1KO mice, DKO mice phenocopy the salient features of the H6PDHKO, displaying reduced body mass, muscle atrophy, and vacuolation of type II fiber-rich muscle, fasting hypoglycemia, increased muscle glycogen deposition, and elevated expression of UPR genes. We propose that muscle G6P metabolism through H6PDH may be as important as changes in the redox environment when considering the mechanism underlying the activation of the UPR and the ensuing myopathy in H6PDHKO and DKO mice. These data are consistent with an 11β-HSD1-independent function for H6PDH in which sarcoplasmic reticulum G6P metabolism and nicotinamide adenine dinucleotide phosphate-(oxidized)\\/nicotinamide adenine dinucleotide phosphate (reduced) redox status are important for maintaining muscle homeostasis.

  6. Construction of differentially expressed cDNA libraries of aldehyde dehydrogenase with high and low activity from tongue squamous carcinoma Tca8113 cell line%基于舌鳞癌Tca8113细胞醛脱氢酶活性不同构建差异表达基因cDNA文库

    Institute of Scientific and Technical Information of China (English)

    孙守娟; 季平; 邓诚; 李颖; 邹波; 漆小娟

    2012-01-01

    Objective To construct the differentially expressed cDNA libraries of aldehyde dehydro genase with high and low activity (ALDHhigh/ALDHlow) from tongue squamous carcinoma Tca8113 cell line. Methods Expression of stem cell marker ALDH was detected, and ALDHhighand ALDHlow cells were collected by Aldefluor assay combined with flow cytometry. Differentially expressed genes of total RNA that was extracted from the two cell subpopulations by Trizol were screened and amplified by suppressing subtractive hybridization ( SSH) , and the PCR products were connected with pMD18-T vector and then transfected into E. Coli DH5a for amplification. Enzyme digestion, gene sequencing and homology analysis were performed in 24 positive clones that were randomly picked from each library. Results Two subproportions of ALDHhigh and ALDHlowwere " screened out, and ALDHhigh cells in Tca8113 cells accounted for 2. 5%. RNA D(260)/D(280) of ALDHhigh and ALDHlow were 1. 93 and 1. 92, respectively. Two-directional subtractive cDNA libraries of ALDHhigh and ALDHlow were constructed, and each library comprised 500 clones. PCR analysis of 24 clones randomly picked from each library showed that insert-fragments distributed in 200 - 700 bp, and no false positive clones were detected. Gene sequencing result that was analyzed and indexed by PubMed showed that cancer related genes included SLC25A13, KLHL2, NPC1, WAPL, BARD1, Notch2 and EEF2K. Conclusion Two-directional subtractive cDNA libraries of ALDHhigh and ALDHlow cells were successfully constructed.%目的 构建舌鳞癌Tca8113细胞系中高、低醛脱氢酶活性(high/low aldehyde dehydrogenase activity,ALDHhigh/ALDHlow)细胞差异表达基因cDNA文库.方法 用流式细胞仪检测ALDEFLUOR(R)染色的Tca8113细胞中干细胞标志物ALDH的表达,并收集ALDHhigh和ALDHlow细胞;用Trizol分别提取两亚群细胞的总RNA;用抑制性消减杂交(SSH)对2组RNA进行差异基因筛选和扩增,扩增产物与pMD18-T载体

  7. Biological function analysis of differentially expressed genes of primary glioblastomas of isocitrate dehydrogenase 1 mutation%异柠檬酸脱氢酶1突变的原发性胶质母细胞瘤差异表达基因的生物学功能分析

    Institute of Scientific and Technical Information of China (English)

    胡慧敏; 王政; 江涛

    2016-01-01

    Objective To investigate the biological function of differentially expressed genes of primary glioblastomas of isocitrate dehydrogenase 1 (IDH1) mutation.Methods A total of 69 patients with primary glioblastoma from Chinese Glioma Genome Atlas who received surgical resection and then received radiotherapy and alkylating chemotherapy between January 2005 and December 2009 were collected.After the extraction of tissue RNA,the whole genome microarray analysis was performed ; after the extraction of tissue DNA,pyrosequencing was performed in order to detect the status of IDH1 gene mutation.The tissue samples were divided into either an IDH1 gene mutation type or an IDH1 wild type according to whether there was a point mutation or not.The RNA expression profile data of the samples were analyzed by using the BRB Array Tools.The differentially expressed genes were obtained between the 2 groups.Omics analysis software OmicsBean was used to conduct the biological function annotation and protein-protein interaction network analysis for differentially expressed genes of mutant wild-type IDH1 in two groups of cases.Results In the 2 groups of samples of the IDH1 gene mutation type and the IDH1 wild type,there were significant differences in a total of 525 gene expressions.The 148 genes up-regulated in the expression level in the IDH1 gene mutation type primary glioblastomas mainly reflected the alterations of energy metabolism and protein metabolism after IDH1 mutation (such as tricarboxylic acid cycle and multiple amino acid metabolism),whereas the 377 genes down-regulated in the expression level were mainly involved in the cell adhesion,the interaction of extracellular matrix and receptors and other biological processes.Conclusion IDH1 mutation caused the changes in biological processes including energy metabolism,protein metabolism,and the expression levels of some cancer-related genes in gliomas.%目的 探讨异柠檬酸脱氢酶1(IDH1)突变的原发性胶质母细胞瘤

  8. The role of glutamate dehydrogenase in mammalian ammonia metabolism.

    Science.gov (United States)

    Spanaki, Cleanthe; Plaitakis, Andreas

    2012-01-01

    Glutamate dehydrogenase (GDH) catalyzes the reversible inter-conversion of glutamate to α-ketoglutarate and ammonia. High levels of GDH activity is found in mammalian liver, kidney, brain, and pancreas. In the liver, GDH reaction appears to be close-to-equilibrium, providing the appropriate ratio of ammonia and amino acids for urea synthesis in periportal hepatocytes. In addition, GDH produces glutamate for glutamine synthesis in a small rim of pericentral hepatocytes. Hence, hepatic GDH can be either a source for ammonia or an ammonia scavenger. In the kidney, GDH function produces ammonia from glutamate to control acidosis. In the human, the presence of two differentially regulated isoforms (hGDH1 and hGDH2) suggests a complex role for GDH in ammonia homeostasis. Whereas hGDH1 is sensitive to GTP inhibition, hGDH2 has dissociated its function from GTP control. Furthermore, hGDH2 shows a lower optimal pH than hGDH1. The hGDH2 enzyme is selectively expressed in human astrocytes and Sertoli cells, probably facilitating metabolic recycling processes essential for their supportive role. Here, we report that hGDH2 is also expressed in the epithelial cells lining the convoluted tubules of the renal cortex. As hGDH2 functions more efficiently under acidotic conditions without the operation of the GTP energy switch, its presence in the kidney may increase the efficacy of the organ to maintain acid base equilibrium.

  9. Glutamate dehydrogenase 1 and SIRT4 regulate glial development.

    Science.gov (United States)

    Komlos, Daniel; Mann, Kara D; Zhuo, Yue; Ricupero, Christopher L; Hart, Ronald P; Liu, Alice Y-C; Firestein, Bonnie L

    2013-03-01

    Congenital hyperinsulinism/hyperammonemia (HI/HA) syndrome is caused by an activation mutation of glutamate dehydrogenase 1 (GDH1), a mitochondrial enzyme responsible for the reversible interconversion between glutamate and α-ketoglutarate. The syndrome presents clinically with hyperammonemia, significant episodic hypoglycemia, seizures, and frequent incidences of developmental and learning defects. Clinical research has implicated that although some of the developmental and neurological defects may be attributed to hypoglycemia, some characteristics cannot be ascribed to low glucose and as hyperammonemia is generally mild and asymptomatic, there exists the possibility that altered GDH1 activity within the brain leads to some clinical changes. GDH1 is allosterically regulated by many factors, and has been shown to be inhibited by the ADP-ribosyltransferase sirtuin 4 (SIRT4), a mitochondrially localized sirtuin. Here we show that SIRT4 is localized to mitochondria within the brain. SIRT4 is highly expressed in glial cells, specifically astrocytes, in the postnatal brain and in radial glia during embryogenesis. Furthermore, SIRT4 protein decreases in expression during development. We show that factors known to allosterically regulate GDH1 alter gliogenesis in CTX8 cells, a novel radial glial cell line. We find that SIRT4 and GDH1 overexpression play antagonistic roles in regulating gliogenesis and that a mutant variant of GDH1 found in HI/HA patients accelerates the development of glia from cultured radial glia cells.

  10. Crystallization and preliminary X-ray diffraction analysis of L-threonine dehydrogenase (TDH) from the hyperthermophilic archaeon Thermococcus kodakaraensis.

    Science.gov (United States)

    Bowyer, A; Mikolajek, H; Wright, J N; Coker, A; Erskine, P T; Cooper, J B; Bashir, Q; Rashid, N; Jamil, F; Akhtar, M

    2008-09-01

    The enzyme L-threonine dehydrogenase catalyses the NAD(+)-dependent conversion of L-threonine to 2-amino-3-ketobutyrate, which is the first reaction of a two-step biochemical pathway involved in the metabolism of threonine to glycine. Here, the crystallization and preliminary crystallographic analysis of L-threonine dehydrogenase (Tk-TDH) from the hyperthermophilic organism Thermococcus kodakaraensis KOD1 is reported. This threonine dehydrogenase consists of 350 amino acids, with a molecular weight of 38 kDa, and was prepared using an Escherichia coli expression system. The purified native protein was crystallized using the hanging-drop vapour-diffusion method and crystals grew in the tetragonal space group P4(3)2(1)2, with unit-cell parameters a = b = 124.5, c = 271.1 A. Diffraction data were collected to 2.6 A resolution and preliminary analysis indicates that there are four molecules in the asymmetric unit of the crystal.

  11. The structure of retinal dehydrogenase type II at 2.7 A resolution: implications for retinal specificity.

    Science.gov (United States)

    Lamb, A L; Newcomer, M E

    1999-05-11

    Retinoic acid, a hormonally active form of vitamin A, is produced in vivo in a two step process: retinol is oxidized to retinal and retinal is oxidized to retinoic acid. Retinal dehydrogenase type II (RalDH2) catalyzes this last step in the production of retinoic acid in the early embryo, possibly producing this putative morphogen to initiate pattern formation. The enzyme is also found in the adult animal, where it is expressed in the testis, lung, and brain among other tissues. The crystal structure of retinal dehydrogenase type II cocrystallized with nicotinamide adenine dinucleotide (NAD) has been determined at 2.7 A resolution. The structure was solved by molecular replacement using the crystal structure of a mitochondrial aldehyde dehydrogenase (ALDH2) as a model. Unlike what has been described for the structures of two aldehyde dehydrogenases involved in the metabolism of acetaldehyde, the substrate access channel is not a preformed cavity into which acetaldehyde can readily diffuse. Retinal dehydrogenase appears to utilize a disordered loop in the substrate access channel to discriminate between retinaldehyde and short-chain aldehydes.

  12. Escherichia coli D-malate dehydrogenase, a generalist enzyme active in the leucine biosynthesis pathway.

    Science.gov (United States)

    Vorobieva, Anastassia A; Khan, Mohammad Shahneawz; Soumillion, Patrice

    2014-10-17

    The enzymes of the β-decarboxylating dehydrogenase superfamily catalyze the oxidative decarboxylation of D-malate-based substrates with various specificities. Here, we show that, in addition to its natural function affording bacterial growth on D-malate as a carbon source, the D-malate dehydrogenase of Escherichia coli (EcDmlA) naturally expressed from its chromosomal gene is capable of complementing leucine auxotrophy in a leuB(-) strain lacking the paralogous isopropylmalate dehydrogenase enzyme. To our knowledge, this is the first example of an enzyme that contributes with a physiologically relevant level of activity to two distinct pathways of the core metabolism while expressed from its chromosomal locus. EcDmlA features relatively high catalytic activity on at least three different substrates (L(+)-tartrate, D-malate, and 3-isopropylmalate). Because of these properties both in vivo and in vitro, EcDmlA may be defined as a generalist enzyme. Phylogenetic analysis highlights an ancient origin of DmlA, indicating that the enzyme has maintained its generalist character throughout evolution. We discuss the implication of these findings for protein evolution.

  13. 对称性肢端角化病皮损中脂肪酸结合蛋白5及二氢硫辛酰胺脱氢酶表达%Expressions of fatty acid binding-protein 5 and dihydrolipoamide dehydrogenase in skin lesions of symmetrical acrokeratoderma

    Institute of Scientific and Technical Information of China (English)

    杨珮珮; 彭晶; 于作忠; 施歌; 黎兆军; 张国学; 樊翌明

    2015-01-01

    Objective To investigate the expressions of fatty acid-binding protein 5 (FABP5)and dihydroli-poamide dehydrogenase(DLD)in skin lesions of symmetrical acrokeratoderma(SAK), and to explore their significance. Methods Biopsy specimens were obtained from skin lesions on the wrists and perilesional skin of 9 patients with SAK, and from normal skin in the wrists of 9 healthy volunteers (control group). Reverse transcription PCR (RT-PCR)and immunohistochemical staining were performed to measure the expressions of FABP5 and DLD in these specimens. Results RT-PCR showed no significant differences in the mRNA expressions of FABP5 or DLD between lesional, perilesional and normal control skin specimens(both P > 0.05). Immunohistochemically, there was a significant increase in the extent and intensity of staining for FABP5 in SAK lesions. Concretely speaking, FABP5 was strongly expressed in the stratum corneum, granular and spinous layers in SAK lesions, but weakly expressed in the stratum corneum, granular and spinous layers in perilesional skin, and only in spinous and basal layers in normal control skin. The expression of DLD decreased in SAK lesions, and was observed only in the stratum corneum and spinous layer in a few cases of SAK. However, the full-thickness epidermis stained positive for DLD in perilesional skin, with the nuclei and cytoplasm both stained deep brown. Conclusion The overexpression of FABP5 in SAK lesions may participate in dysdifferentiation of keratinocytes, while the down-regulation of DLD expression suggests an imbalance in energy metabolism.%目的:探讨脂肪酸结合蛋白5(FABP5)及二氢硫辛酰胺脱氢酶(DLD)在对称性肢端角化病中的表达和意义。方法收集9例对称性肢端角化病患者腕部皮损及其周围皮肤活检标本,9例健康人腕部皮肤为对照,用逆转录 PCR(RT-PCR)及免疫组化法检测 FABP5及 DLD 表达水平。结果 RT-PCR 显示,FABP5 mRNA 及 DLD mRNA 表达在对称性

  14. Studies on the structure and function of pyruvate dehydrogenase complexes

    NARCIS (Netherlands)

    Abreu, de R.A.

    1978-01-01

    The aim of the present investigation was to obtain more information of the structure and function of the pyruvate dehydrogenase complexes from Azotobacter vinelandii and Escherichia coli.In chapter 2 a survey is given of the recent literature on pyruvate dehydrogenase complexes.In chapter 3 results

  15. Isolation and characterization of an apple cytosolic malate dehydrogenase gene reveal its function in malate synthesis.

    Science.gov (United States)

    Yao, Yu-Xin; Li, Ming; Zhai, Heng; You, Chun-Xiang; Hao, Yu-Jin

    2011-03-15

    Cytosolic NAD-dependent malate dehydrogenase (cyMDH) is an enzyme crucial for malate synthesis in the cytosol. The apple MdcyMDH gene (GenBank Accession No. DQ221207) encoding the cyMDH enzyme in apple was cloned and functionally characterized. The protein was subcellularly localized to the cytoplasm and plasma membrane. Based on kinetic parameters, it mainly catalyzes the reaction from oxalacetic acid (OAA) to malate in vitro. The expression level of MdcyMDH was positively correlated with malate dehydrogenase (MDH) activity throughout fruit development, but not with malate content, especially in the ripening apple fruit. MdcyMDH overexpression contributed to malate accumulation in the apple callus and tomato. Taken together, our results support the involvement of MdcyMDH directly in malate synthesis and indirectly in malate accumulation through the regulation of genes/enzymes associated with malate degradation and transportation, gluconeogenesis and the tricarboxylic acid cycle.

  16. Biochemical and molecular characterization of the NAD(+)-dependent isocitrate dehydrogenase from the chemolithotroph Acidithiobacillus thiooxidans.

    Science.gov (United States)

    Inoue, Hiroyuki; Tamura, Takashi; Ehara, Nagisa; Nishito, Akira; Nakayama, Yumi; Maekawa, Makiko; Imada, Katsumi; Tanaka, Hidehiko; Inagaki, Kenji

    2002-08-27

    An isocitrate dehydrogenase (ICDH) with an unique coenzyme specificity from Acidithiobacillus thiooxidans was purified and characterized, and its gene was cloned. The native enzyme was homodimeric with a subunit of M(r) 45000 and showed a 78-fold preference for NAD(+) over NADP(+). The cloned ICDH gene (icd) was expressed in an icd-deficient strain of Escherichia coli EB106; the activity was found in the cell extract. The gene encodes a 429-amino acid polypeptide and is located between open reading frames encoding a putative aconitase gene (upstream of icd) and a putative succinyl-CoA synthase beta-subunit gene (downstream of icd). A. thiooxidans ICDH showed high sequence similarity to bacterial NADP(+)-dependent ICDH rather than eukaryotic NAD(+)-dependent ICDH, but the NAD(+)-preference of the enzyme was suggested due to residues conserved in the coenzyme binding site of the NAD(+)-dependent decarboxylating dehydrogenase.

  17. 海马齿甜菜碱醛脱氢酶基因克隆、高效表达及酶学特性分析%Cloning, Expression, and Enzymatic Characteristics of Betaine Aldehyde De-hydrogenase Gene inSesuvium portulacastrum L.

    Institute of Scientific and Technical Information of China (English)

    喻时周; 杨成龙; 郭建春; 段瑞军

    2016-01-01

    在许多渗透调节剂中,甜菜碱是最理想的有机小分子渗透调节物质。甜菜碱在植物体内大量积累不会带来危害,同时能提高植物对环境胁迫的抗性。将海马齿中克隆到的甜菜碱醛脱氢酶基因构建到表达载体pET-28a(+)上,获得重组载体pET-SpBADH并将其成功地转化到BL21(DE3)中得到重组工程菌,经IPTG诱导能高效表达55 kD目的蛋白,表达量可以达到301µg mL–1。酶学特征分析表明,该蛋白最适pH值为7.2,在偏碱条件下能维持较高的催化活性; SpBADH蛋白对高温敏感,且温度对催化活性影响较大,超过55℃时酶活性只有20%,最适酶催化活性温度为37℃;而有机小分子醇类对酶的催化活性有保护作用,可以通过自身特征维持酶催化活性的微环境。%Among many osmotic materials, glycine betaine is a best organic micro-molecular, and functionally works for osmotic regulation in plants, which is non-toxic to plant growth. A lot of glycine betaine accumulatedin plant can enhance the resistance of plants to environmental stresses. In the study, a full-length sequence of betaine aldehyde dehydrogenase gene fromSesuvium portulacastrum was ligated with the vector pET-[28a](+), named pET-SpBADH, and successfully transformed into BL21(DE3) to obtain the corresponding recombinant engineering bacteria, which could highly express 55 kD protein induced by IPTG, with the expression level to 301 µg mL–1. The purified protein was obtained, showing the optimum pH value of 7.2, and maintain high catalytic activity the enzyme under slightly alkaline conditions. SpBADH protein very sensitive to high temperature effected the enzyme activity, with the optimum temperature to 37℃. The enzyme activity was only 20% when temperature was over 55℃. The small organic molecules of the reveral compounds of alcohol had a protective effect on the catalytic activity of the enzyme. The microenvironment of catalytic activity could be

  18. INFLUENCE OF SELECTED PHARMACEUTICALS ON ACTIVATED SLUDGE DEHYDROGENASE ACTIVITY

    Directory of Open Access Journals (Sweden)

    Agnieszka Tomska

    2016-06-01

    The aim of this work was to evaluate the effect of selected antibiotics - sulfanilamide and erythromycin on activated sludge dehydrogenase activity with use of trifenyltetrazolinum chloride (TTC test. Dehydrogenases activity is an indicator of biochemical activity of microorganisms present in activated sludge or the ability to degrade organic compounds in waste water. TTC test is particularly useful for the regularity of the course of treatment, in which the presence of inhibitors of biochemical reactions and toxic compounds are present. It was observed that the dehydrogenase activity decreases with the increase of a antibiotics concentration. The lowest value of the dehydrogenase activity equal to 32.4 μmol TF / gMLSS obtained at sulfanilamide concentration 150mg / l. For this sample, an inhibition of dehydrogenase activity was 31%.

  19. Mitochondrial malate dehydrogenase lowers leaf respiration and alters photorespiration and plant growth in Arabidopsis.

    Science.gov (United States)

    Tomaz, Tiago; Bagard, Matthieu; Pracharoenwattana, Itsara; Lindén, Pernilla; Lee, Chun Pong; Carroll, Adam J; Ströher, Elke; Smith, Steven M; Gardeström, Per; Millar, A Harvey

    2010-11-01

    Malate dehydrogenase (MDH) catalyzes a reversible NAD(+)-dependent-dehydrogenase reaction involved in central metabolism and redox homeostasis between organelle compartments. To explore the role of mitochondrial MDH (mMDH) in Arabidopsis (Arabidopsis thaliana), knockout single and double mutants for the highly expressed mMDH1 and lower expressed mMDH2 isoforms were constructed and analyzed. A mmdh1mmdh2 mutant has no detectable mMDH activity but is viable, albeit small and slow growing. Quantitative proteome analysis of mitochondria shows changes in other mitochondrial NAD-linked dehydrogenases, indicating a reorganization of such enzymes in the mitochondrial matrix. The slow-growing mmdh1mmdh2 mutant has elevated leaf respiration rate in the dark and light, without loss of photosynthetic capacity, suggesting that mMDH normally uses NADH to reduce oxaloacetate to malate, which is then exported to the cytosol, rather than to drive mitochondrial respiration. Increased respiratory rate in leaves can account in part for the low net CO(2) assimilation and slow growth rate of mmdh1mmdh2. Loss of mMDH also affects photorespiration, as evidenced by a lower postillumination burst, alterations in CO(2) assimilation/intercellular CO(2) curves at low CO(2), and the light-dependent elevated concentration of photorespiratory metabolites. Complementation of mmdh1mmdh2 with an mMDH cDNA recovered mMDH activity, suppressed respiratory rate, ameliorated changes to photorespiration, and increased plant growth. A previously established inverse correlation between mMDH and ascorbate content in tomato (Solanum lycopersicum) has been consolidated in Arabidopsis and may potentially be linked to decreased galactonolactone dehydrogenase content in mitochondria in the mutant. Overall, a central yet complex role for mMDH emerges in the partitioning of carbon and energy in leaves, providing new directions for bioengineering of plant growth rate and a new insight into the molecular mechanisms

  20. Enantiocomplementary Yarrowia lipolytica Oxidoreductases: Alcohol Dehydrogenase 2 and Short Chain Dehydrogenase/Reductase

    Directory of Open Access Journals (Sweden)

    Margit Winkler

    2013-08-01

    Full Text Available Enzymes of the non-conventional yeast Yarrowia lipolytica seem to be tailor-made for the conversion of lipophilic substrates. Herein, we cloned and overexpressed the Zn-dependent alcohol dehydrogenase ADH2 from Yarrowia lipolytica in Escherichia coli. The purified enzyme was characterized in vitro. The substrate scope for YlADH2 mediated oxidation and reduction was investigated spectrophotometrically and the enzyme showed a broader substrate range than its homolog from Saccharomyces cerevisiae. A preference for secondary compared to primary alcohols in oxidation direction was observed for YlADH2. 2-Octanone was investigated in reduction mode in detail. Remarkably, YlADH2 displays perfect (S-selectivity and together with a highly (R-selective short chain dehydrogenase/ reductase from Yarrowia lipolytica it is possible to access both enantiomers of 2-octanol in >99% ee with Yarrowia lipolytica oxidoreductases.

  1. Stability of immobilized yeast alcohol dehydrogenase

    Energy Technology Data Exchange (ETDEWEB)

    Ooshima, H.; Genko, Y.; Harano, Y.

    1981-12-01

    The effects of substrate on stabilities of native (NA) and three kinds of immobilized yeast alcohol dehydrogenase (IMA), namely PGA (the carrier; porous glass), SEA (agarose gel) prepared covalently, and AMA (anion-exchange resin) prepared ionically, were studied. The following results were obtained. 1) The deactivations of NA and IMA free from the substrate or in the presence of ethanol obey the first-order kinetics, whereas, in the presence of butyraldehyde, their deactivation behaviors are explained on the basis of coexistence of two components of YADHs, namely the labile E1 and the comparatively stable E2, with different first-order deactivation constants. (2) A few attempts for stabilization of IMA were carried out from the viewpoint of the effects of crosslinkages among the subunits of YADH for PGA and the multibonding between the carrier and enzyme for SEA. The former is effective for the stabilization, whereas the latter is not. (Refs. 19).

  2. Interactions between heparinoids and alcohol dehydrogenase.

    Science.gov (United States)

    Paulíková, H; Valusová, E; Antalík, M

    1997-07-01

    The interaction between polysulfated polysaecharides (low-molecular-weight heparin LMWH, dextran sulfate DS and pentosan sulfate PS) and yeast alcohol dehydrogenase (YADH) was investigated. The fluorescence and UV spectra of YADH after adding the tested polysaccharides have confirmed the interaction between the enzyme and these compounds. Kinetic studies have shown that LMWH, DS and PS are inhibitors of YADH (mixed type with respect to NAD). The most potent inhibitor is PS (ID50=37.5 ng/ml, Ki=0.6 muM). The inhibition effect depends on the ionic strength (the inhibition decreased by about 50% in the presence of 100 mM Na2SO4) and pH value (the inhibition decreased at pH>7). The results indicate that the inhibition effect of these polyanions is caused by their electrostatic interactions with the NAD-binding region of YADH.

  3. Untangling the glutamate dehydrogenase allosteric nightmare.

    Science.gov (United States)

    Smith, Thomas J; Stanley, Charles A

    2008-11-01

    Glutamate dehydrogenase (GDH) is found in all living organisms, but only animal GDH is regulated by a large repertoire of metabolites. More than 50 years of research to better understand the mechanism and role of this allosteric network has been frustrated by its sheer complexity. However, recent studies have begun to tease out how and why this complex behavior evolved. Much of GDH regulation probably occurs by controlling a complex ballet of motion necessary for catalytic turnover and has evolved concomitantly with a long antenna-like feature of the structure of the enzyme. Ciliates, the 'missing link' in GDH evolution, might have created the antenna to accommodate changing organelle functions and was refined in humans to, at least in part, link amino acid catabolism with insulin secretion.

  4. The role of the NAD-dependent glutamate dehydrogenase in restoring growth on glucose of a Saccharomyces cerevisiae phosphoglucose isomerase mutant.

    Science.gov (United States)

    Boles, E; Lehnert, W; Zimmermann, F K

    1993-10-01

    Phosphoglucose isomerase pgi1-deletion mutants of Saccharomyces cerevisiae cannot grow on glucose as the sole carbon source and are even inhibited by glucose. These growth defects could be suppressed by an over-expression on a multi-copy plasmid of the structural gene GDH2 coding for the NAD-dependent glutamate dehydrogenase. GDH2 codes for a protein with 1092 amino acids which is located on chromosome XII and shows high sequence similarity to the Neurospora crassa NAD-glutamate dehydrogenase. Suppression of the pgi1 deletion by over-expression of GDH2 was abolished in strains with a deletion of the glucose-6-phosphate dehydrogenase gene ZWF1 or gene GDH1 coding for the NADPH-dependent glutamate dehydrogenase. Moreover, this suppression required functional mitochondria. It is proposed that the growth defect of pgi1 deletion mutants on glucose is due to a rapid depletion of NADP which is needed as a cofactor in the oxidative reactions of the pentose phosphate pathway. Over-expression of the NAD-dependent glutamate dehydrogenase leads to a very efficient conversion of glutamate with NADH generation to 2-oxoglutarate which can be converted back to glutamate by the NADPH-dependent glutamate dehydrogenase with the consumption of NADPH. Consequently, over-expression of the NAD-dependent glutamate dehydrogenase causes a substrate cycling between 2-oxoglutarate and glutamate which restores NADP from NADPH through the coupled conversion of NAD to NADH which can be oxidized in the mitochondria. Furthermore, the requirement for an increase in NADPH consumption for the suppression of the phosphoglucose isomerase defect could be met by addition of oxidizing agents which are known to reduce the level of NADPH.

  5. Expression of 11β-hydroxysteroid dehydrogenase type 1 on hippocampus of rat with chronic unpredictable mild stress%11β-羟基类固醇脱氢酶-1在慢性温和应激抑郁大鼠海马组织中的表达

    Institute of Scientific and Technical Information of China (English)

    程世翔; 涂悦; 张赛; 文立; 刘晓智

    2012-01-01

    Objective To investigate the roles of 11 β-hydroxysteroid dehydrogenase type 1 ( 11 β-HSD1 )on hippocampus of rat with chronic unpredictable mild stress (CUMS).Methods Twenty-four male SpragueDawley rats were randomly divided into control group and depressive model group. Chronic unpredictable mild stress (CUMS) was used to make up depressive animal model.Behavioral changes were recorded by body weight measuring,sucrose consumption test (SCT) and open field test (OFT),respectively.The mRNA transcription of 11β-HSD1 in hippocampus tissues of the rats were detected by real-time RT-PCR,and the protein expression of 11β-HSD1 were detected by western blot and immunofluorescence.Results Bcforc starting CUMS protocol,the rats exhibited equivalent weight and sucrose consumption.Twenty-eight days after CUMS protocol,behavior parameters such as body weight,sucrose consumption,nunber of crossing,and number of rearing were significantly decreased in rats exposed to CUMS group compared with control group (P < 0.05,P < 0.01 ).Correspondingly,realtime RT-PCR assays showed the mRNA expression of 11 β-HSD1 in the hippocampus of CUMS group,which was (31 ±9) % lower than that of control group.Meanwhile,the protein expression of it in CUMS group was lower than that of control group (P < 0.05 ).Inmunofluorescence revealed that the number of positive 11 3-HSD1 cells was high (223 ± 13) in the control group,while the number was decreased prominently (92 ± 11 ) in the CUMS group (P < 0.01 ).Conclusion Depressive behavior of rats is induced and the expression of 11 β-HSD1 in the hippocampus is decreased prominently by CUMS,the mechanism of which is at least related to the low expression of 11β-HSD1 and disturbance of glucocorticoid metabolism caused by CUMS.%目的 应用慢性温和不可预知刺激( CUMS)建立抑郁症动物模型,探讨大鼠海马组织中11β-羟基类固醇脱氢酶-1(11β-HSD1)蛋白表达以及抑郁症的发病机制.方法 将24只Sprague

  6. cDNA Cloning and Expression Analysis of Glutamate Dehydrogenase in Chinese Shrimp (Fenneropenaeus chinensis) Exposed to Ambient Ammonia%氨氮胁迫下中国明对虾(Fenneropenaeus chinensis)谷氨酸脱氢酶基因的表达分析

    Institute of Scientific and Technical Information of China (English)

    何玉英; 李少飞; 王清印; 李健

    2016-01-01

    Chinese shrimp (Fenneropenaeus chinensis) is an ecologically and economically important shrimp species. During the culture, F. chinensis were exposed to a series of stressors that adversely affect biological activities including growth rate. Ammonia, a product of protein degradation and bacterial activity, is a strong stressor in shrimp aquaculture. Glutamate dehydrogenase (GDH) is an abundant and ubiquitous mitochondrial enzyme that catalyzes reversible amination of glutamate. cDNA of GDH from F. chinensis (FcGDH) was cloned by rapid amplification of cDNA ends (RACE). The FcGDH cDNA was 1779 bp in size, and it included a 1659-bp open reading frame (ORF) that encoded a 522 amino-acid polypeptide of which the isoelectric point (pI) was 6.54 and the molecular mass was 61.3 kDa. Homology analysis revealed that the amino acid sequence of FcGDH was highly conserved with its homologs in other arthropod. The similarities between FcGDH and GDHs of Litopenaeus vannamei and Eriocheir sinensis were 98% and 89% respectively. Phylogenetic analysis showed that FcGDH was in the same branch with that of L. vannamei and then in the same branches with those of E. sinensis, Drosophila melanogaster, and Aedes aegypti in order. The tissue expression analysis showed that FcGDH was detected in all tested tissues including muscle, gill, hepatopancreas, stomach, intestine, lymph, and hemocytes. The highest expression of FcGDH was in the muscle that was an amino acid pool and the major tissue for protein deposition. After exposure to ambient ammonia, the expression of FcGDH gene was up-regulated significantly in muscles compared to the control group (P<0.01). The expression level of FcGDH in hepatopancreas was down-regulated significantly at 3 h (P<0.05), and was then stabilized up to 24 h. The expression of FcGDH was increased significantly after 48 h and reached the maximum at 72 h compared to the control group (P<0.01). These results implied that FcGDH might play an important role in the

  7. The expressions and correlation of isocitrate dehydrogenase 1 and matrix metalloproteinase-2 in human glioma%脑胶质瘤异柠檬酸脱氢酶1基因突变与基质金属蛋白酶2表达的研究

    Institute of Scientific and Technical Information of China (English)

    寿记新; 高海东; 刘菲菲; 付旭东; 王酩; 管海博; 王建业; 周少龙; 郭利刚

    2016-01-01

    目的 探讨异柠檬酸脱氢酶1(IDH1)基因突变和基质金属蛋白酶-2(MMP-2)在脑胶质瘤中的表达特性和相关性.方法 用反转录-聚合酶链反应(RT-PCR)法测序IDH1基因在胶质瘤中的序列变化;链霉菌抗生物素蛋白-过氧化物酶(SP)法分析50例原发性脑胶质瘤和10例对照组中MMP-2蛋白的表达.结果 (1)经基因直接测序IDH1基因在M及M1组共50例脑胶质细胞瘤组织中突变率较10例正常脑组织明显上升(总体上升率为56.35%,P<0.05),序列变化位点多为R132,IDH1基因片段变异性与其恶性分级无明显相关(P>0.05);(2)M及M1组共50例脑胶质细胞瘤组织中MMP-2表达比10例正常脑组织显著增强(总体增强率为57.95%,P<0.05),MMP-2表达率与胶质瘤恶性分级呈正相关(r=0.712,P<0.01);(3)所有10例脑室造瘘患者即对照组标本中均未见明显IDH1基因突变及MMP-2过表达.结论 (1)IDH1基因突变与胶质瘤进展关系密切,对于评判预后有积极意义;(2) MMP-2蛋白的表达与胶质瘤的恶性分级关系密切,呈正相关;(3)IDH1基因、MMP-2蛋白联合检测有助于分析胶质瘤恶性程度及预后.%Objective To investigate the isocitrate dehydrogenase 1 (IDH1) gene mutation and the matrix metalloproteinase (MMP)-2 protein in human ghoma.Methods The expressions of MMP-2 in 60 cases of gliomas were detected by using the two-step immunohistochemical staining method.The gauging of IDH1 gene mutation were using by the reverse transcriptase-polymerase chain reaction (RT-PCR).The relationship between that of IDH1 and MMP-2 expression was analyzed by statistical method.Results (1) The expression of MMP-2 and IDH1 genes in 50 cases human gliomas were significant higher than that in 10 cases normal brain tissues (the rate is 56.35%,P < 0.05),What' s more,most of IDH1 genes mutation appeared as R132 type.(2) MMP-2 have a high expression in high grade than low grade in different human glioma (the rate is 57.95

  8. Correlation between mutations of glioma isocitrate dehydrogenase 1 gene and expression of glioma stem cell-related gene%胶质瘤IDH1基因突变与胶质瘤干细胞相关基因表达的相关性研究

    Institute of Scientific and Technical Information of China (English)

    王继超; 郑勇; 杨小朋; 吴永刚; 吴红星; 杨乐; 张诚

    2012-01-01

    目的 研究原发性、原位复发性胶质瘤中异柠檬酸脱氢酶1(IDHI)基因突变情况,分析胶质瘤干细胞相关基因的变化情况与IDH1基因突变的相关性. 方法 选取新疆自治区人民医院神经外科自2010年8月至2011年8月间手术切除并经病理证实的人脑胶质瘤标本43例,其中原发30例,复发13例,应用PCR检测标本中IDH1基因多态性,流式细胞术检测肿瘤组织中CD133、nestin的表达. 结果 基因测序显示原发胶质瘤中17例(56.67%)发生IDH1突变,复发胶质瘤中13例(53.85%)发生IDHl突变,突变类型均为R132H型.流式细胞仪检测显示原发、复发胶质瘤标本中nestin、CD133的阳性表达率与肿瘤的病理分级均成正相关关系(P<0.05).伴IDHl突变的胶质瘤标本nestin、CD133阳性表达率较IDH1野生型胶质瘤增多,差异有统计学意义(P<0.05).与原发肿瘤比较,复发肿瘤中nestin、CD133阳性细胞表达率明显增高,差异有统计学意义(P<0.05). 结论 IDH1突变在原发、复发性胶质瘤中发生频率均很高,可上调干细胞相关基因Nestin和CD133的表达.复发肿瘤中升高的干细胞相关基因与肿瘤发生及复发密切相关.%Objective To study the distribution of isocitrate dehydrogenase (IDH1) gene mutations in primary and recurrent gliomas, and their correlation with expression of glioma stem cell-related gene. Methods Forty-three human glioma specimens,collected during the resection in our hospital from August 2010 to August 2011 and confirmed by pathology, were chosen, including 30 having primary gliomas and 13 having recurrent gliomas. The polymorphisms of IDH1 gene were detected by real-time quantitative PCR; the protein expression levels ofnestin and CD133 were measured by flow cytometry. Results Gene sequencing indicated that IDH1 gene mutations were observed in 17 specimens having primary gliomas (56.67%) and 7 specimens having recurrent gliomas (53.85%); and the mutation

  9. External NAD(P)H dehydrogenases in Acanthamoeba castellanii mitochondria.

    Science.gov (United States)

    Antos-Krzeminska, Nina; Jarmuszkiewicz, Wieslawa

    2014-09-01

    The mitochondrial respiratory chain of plants and some fungi contains multiple rotenone-insensitive NAD(P)H dehydrogenases, of which at least two are located on the outer surface of the inner membrane (i.e., external NADH and external NADPH dehydrogenases). Annotated sequences of the putative alternative NAD(P)H dehydrogenases of the protozoan Acanthamoeba castellanii demonstrated similarity to plant and fungal sequences. We also studied activity of these dehydrogenases in isolated A. castellanii mitochondria. External NADPH oxidation was observed for the first time in protist mitochondria. The coupling parameters were similar for external NADH oxidation and external NADPH oxidation, indicating similar efficiencies of ATP synthesis. Both external NADH oxidation and external NADPH oxidation had an optimal pH of 6.8 independent of relevant ubiquinol-oxidizing pathways, the cytochrome pathway or a GMP-stimulated alternative oxidase. The maximal oxidizing activity with external NADH was almost double that with external NADPH. However, a lower Michaelis constant (K(M)) value for external NADPH oxidation was observed compared to that for external NADH oxidation. Stimulation by Ca(2+) was approximately 10 times higher for external NADPH oxidation, while NADH dehydrogenase(s) appeared to be slightly dependent on Ca(2+). Our results indicate that external NAD(P)H dehydrogenases similar to those in plant and fungal mitochondria function in mitochondria of A. castellanii.

  10. Cell wall-associated malate dehydrogenase activity from maize roots.

    Science.gov (United States)

    Hadži-Tašković Šukalović, Vesna; Vuletić, Mirjana; Marković, Ksenija; Vučinić, Zeljko

    2011-10-01

    Isolated cell walls from maize (Zea mays L.) roots exhibited ionically and covalently bound NAD-specific malate dehydrogenase activity. The enzyme catalyses a rapid reduction of oxaloacetate and much slower oxidation of malate. The kinetic and regulatory properties of the cell wall enzyme solubilized with 1M NaCl were different from those published for soluble, mitochondrial or plasma membrane malate dehydrogenase with respect to their ATP, Pi, and pH dependence. Isoelectric focusing of ionically-bound proteins and specific staining for malate dehydrogenase revealed characteristic isoforms present in cell wall isolate, different from those present in plasma membranes and crude homogenate. Much greater activity of cell wall-associated malate dehydrogenase was detected in the intensively growing lateral roots compared to primary root with decreased growth rates. Presence of Zn(2+) and Cu(2+) in the assay medium inhibited the activity of the wall-associated malate dehydrogenase. Exposure of maize plants to excess concentrations of Zn(2+) and Cu(2+) in the hydroponic solution inhibited lateral root growth, decreased malate dehydrogenase activity and changed isoform profiles. The results presented show that cell wall malate dehydrogenase is truly a wall-bound enzyme, and not an artefact of cytoplasmic contamination, involved in the developmental processes, and detoxification of heavy metals.

  11. The Changes of Hepatic,Muscle Glycogen and Succinate Dehydrogenase 3mRNA Expression in Skeletal Muscle of Sport Low Hemoglobin Rats%运动性低血色素大鼠骨骼肌有氧氧化能量代谢系统的变化研究

    Institute of Scientific and Technical Information of China (English)

    张毅

    2011-01-01

    To observe the changes of hepatic,muscle glycogen and succinate dehydrogenase 3mRNA expression in skeletal muscle of sport low hemoglobin rats and to provide a reference for further study on the recovery of the skeletal muscle motor capacity with sports anemia.Method:20 Wister rats were divided into two groups: silent control group(n=10) and training group(n=10).After seven weeks increase mental treadmill exercise,the model of sports anemia was built up.All rats were killed during 24H after training.The Glycogen in liver and skeletal muscle,SDH activity and expression of UCP3mRNA were to be detected and observed.Results:1)Compared with silent control group,the RBC,Hb and HCT of training group decreased significantly(P0.05),so the model was successful;2)There was no significant change in the recovery of the muscle and hepatic glycogen in sports anemia rats(P0.05);3)In sports anemia status,the SDH activity decreased highly significantly(P0.01);4)Expression of UCP3mRNA were increased significantly in sports anemia rats(P0.01).Conclusions: 7 weeks increasing treadmill exercise can make rats appear symptoms of low hemoglobin;Sport low hemoglobin did not affect recovery speed of muscle and hepatic glycogen;the activity of SDH significantly reduce,and increased expression of UCP3mRNA.This may be the reasons that sport low hemoglobin can decrease the rate of athletic aerobic oxidation.%为进一步研究改善贫血状况和采用恢复手段促进骨骼肌的快速恢复打下基础。方法:将20只Wistar大鼠随机分为安静对照组(n=10)和运动组(n=10)。采用7周递增负荷跑台运动建立运动性低血色素大鼠模型,建模成功后第二天宰杀大鼠,取骨骼肌和肝脏测定肌糖原、肝糖原含量,并测定骨骼肌的SDH活性和UCP3mRNA表达。结果:1)7周递增负荷跑台运动导致了运动大鼠红细胞计数、血红蛋白、红细胞压积显著降低(P〈0.05

  12. Undetected Toxicity Risk in Pharmacogenetic Testing for Dihydropyrimidine Dehydrogenase

    Directory of Open Access Journals (Sweden)

    Felicia Stefania Falvella

    2015-04-01

    Full Text Available Fluoropyrimidines, the mainstay agents for the treatment of colorectal cancer, alone or as a part of combination therapies, cause severe adverse reactions in about 10%–30% of patients. Dihydropyrimidine dehydrogenase (DPD, a key enzyme in the catabolism of 5-fluorouracil, has been intensively investigated in relation to fluoropyrimidine toxicity, and several DPD gene (DPYD polymorphisms are associated with decreased enzyme activity and increased risk of fluoropyrimidine-related toxicity. In patients carrying non-functional DPYD variants (c.1905+1G>A, c.1679T>G, c.2846A>T, fluoropyrimidines should be avoided or reduced according to the patients’ homozygous or heterozygous status, respectively. For other common DPYD variants (c.496A>G, c.1129-5923C>G, c.1896T>C, conflicting data are reported and their use in clinical practice still needs to be validated. The high frequency of DPYD polymorphism and the lack of large prospective trials may explain differences in studies’ results. The epigenetic regulation of DPD expression has been recently investigated to explain the variable activity of the enzyme. DPYD promoter methylation and its regulation by microRNAs may affect the toxicity risk of fluoropyrimidines. The studies we reviewed indicate that pharmacogenetic testing is promising to direct personalised dosing of fluoropyrimidines, although further investigations are needed to establish the role of DPD in severe toxicity in patients treated for colorectal cancer.

  13. Nuclear lactate dehydrogenase modulates histone modification in human hepatocytes

    Energy Technology Data Exchange (ETDEWEB)

    Castonguay, Zachary; Auger, Christopher; Thomas, Sean C.; Chahma, M’hamed; Appanna, Vasu D., E-mail: vappanna@laurentian.ca

    2014-11-07

    Highlights: • Nuclear LDH is up-regulated under oxidative stress. • SIRT1 is co-immunoprecipitated bound to nuclear LDH. • Nuclear LDH is involved in histone deacetylation and epigenetics. - Abstract: It is becoming increasingly apparent that the nucleus harbors metabolic enzymes that affect genetic transforming events. Here, we describe a nuclear isoform of lactate dehydrogenase (nLDH) and its ability to orchestrate histone deacetylation by controlling the availability of nicotinamide adenine dinucleotide (NAD{sup +}), a key ingredient of the sirtuin-1 (SIRT1) deacetylase system. There was an increase in the expression of nLDH concomitant with the presence of hydrogen peroxide (H{sub 2}O{sub 2}) in the culture medium. Under oxidative stress, the NAD{sup +} generated by nLDH resulted in the enhanced deacetylation of histones compared to the control hepatocytes despite no discernable change in the levels of SIRT1. There appeared to be an intimate association between nLDH and SIRT1 as these two enzymes co-immunoprecipitated. The ability of nLDH to regulate epigenetic modifications by manipulating NAD{sup +} reveals an intricate link between metabolism and the processing of genetic information.

  14. Regulation of L-threonine dehydrogenase in somatic cell reprogramming.

    Science.gov (United States)

    Han, Chuanchun; Gu, Hao; Wang, Jiaxu; Lu, Weiguang; Mei, Yide; Wu, Mian

    2013-05-01

    Increasing evidence suggests that metabolic remodeling plays an important role in the regulation of somatic cell reprogramming. Threonine catabolism mediated by L-threonine dehydrogenase (TDH) has been recognized as a specific metabolic trait of mouse embryonic stem cells. However, it remains unknown whether TDH-mediated threonine catabolism could regulate reprogramming. Here, we report TDH as a novel regulator of somatic cell reprogramming. Knockdown of TDH inhibits, whereas induction of TDH enhances reprogramming efficiency. Moreover, microRNA-9 post-transcriptionally regulates the expression of TDH and thereby inhibits reprogramming efficiency. Furthermore, protein arginine methyltransferase (PRMT5) interacts with TDH and mediates its post-translational arginine methylation. PRMT5 appears to regulate TDH enzyme activity through both methyltransferase-dependent and -independent mechanisms. Functionally, TDH-facilitated reprogramming efficiency is further enhanced by PRMT5. These results suggest that TDH-mediated threonine catabolism controls somatic cell reprogramming and indicate the importance of post-transcriptional and post-translational regulation of TDH.

  15. Asparaginyl deamidation in two glutamate dehydrogenase isoenzymes from Saccharomyces cerevisiae.

    Science.gov (United States)

    DeLuna, Alexander; Quezada, Héctor; Gómez-Puyou, Armando; González, Alicia

    2005-03-25

    The non-enzymatic deamidation of asparaginyl residues is a major source of spontaneous damage of several proteins under physiological conditions. In many cases, deamidation and isoaspartyl formation alters the biological activity or stability of the native polypeptide. Rates of deamidation of particular residues depend on many factors including protein structure and solvent exposure. Here, we investigated the spontaneous deamidation of the two NADP-glutamate dehydrogenase isoenzymes from Saccharomyces cerevisiae, which have different kinetic properties and are differentially expressed in this yeast. Our results show that Asn54, present in Gdh3p but missing in the GDH1-encoded homologue, is readily deamidated in vitro under alkaline conditions. Relative to the native enzyme, deamidated Gdh3p shows reduced protein stability. The different deamidation rates of the two isoenzymes could explain to some extent, the relative in vivo instability of the allosteric Gdh3p enzyme, compared to that of Gdh1p. It is thus possible that spontaneous asparaginyl modification could play a role in the metabolic regulation of ammonium assimilation and glutamate biosynthesis.

  16. Alternative splicing regulates targeting of malate dehydrogenase in Yarrowia lipolytica.

    Science.gov (United States)

    Kabran, Philomène; Rossignol, Tristan; Gaillardin, Claude; Nicaud, Jean-Marc; Neuvéglise, Cécile

    2012-06-01

    Alternative pre-mRNA splicing is a major mechanism contributing to the proteome complexity of most eukaryotes, especially mammals. In less complex organisms, such as yeasts, the numbers of genes that contain introns are low and cases of alternative splicing (AS) with functional implications are rare. We report the first case of AS with functional consequences in the yeast Yarrowia lipolytica. The splicing pattern was found to govern the cellular localization of malate dehydrogenase, an enzyme of the central carbon metabolism. This ubiquitous enzyme is involved in the tricarboxylic acid cycle in mitochondria and in the glyoxylate cycle, which takes place in peroxisomes and the cytosol. In Saccharomyces cerevisiae, three genes encode three compartment-specific enzymes. In contrast, only two genes exist in Y. lipolytica. One gene (YlMDH1, YALI0D16753g) encodes a predicted mitochondrial protein, whereas the second gene (YlMDH2, YALI0E14190g) generates the cytosolic and peroxisomal forms through the alternative use of two 3'-splice sites in the second intron. Both splicing variants were detected in cDNA libraries obtained from cells grown under different conditions. Mutants expressing the individual YlMdh2p isoforms tagged with fluorescent proteins confirmed that they localized to either the cytosolic or the peroxisomal compartment.

  17. Human choline dehydrogenase: medical promises and biochemical challenges.

    Science.gov (United States)

    Salvi, Francesca; Gadda, Giovanni

    2013-09-15

    Human choline dehydrogenase (CHD) is located in the inner membrane of mitochondria primarily in liver and kidney and catalyzes the oxidation of choline to glycine betaine. Its physiological role is to regulate the concentrations of choline and glycine betaine in the blood and cells. Choline is important for regulation of gene expression, the biosynthesis of lipoproteins and membrane phospholipids and for the biosynthesis of the neurotransmitter acetylcholine; glycine betaine plays important roles as a primary intracellular osmoprotectant and as methyl donor for the biosynthesis of methionine from homocysteine, a required step for the synthesis of the ubiquitous methyl donor S-adenosyl methionine. Recently, CHD has generated considerable medical attention due to its association with various human pathologies, including male infertility, homocysteinuria, breast cancer and metabolic syndrome. Despite the renewed interest, the biochemical characterization of the enzyme has lagged behind due to difficulties in the obtainment of purified, active and stable enzyme. This review article summarizes the medical relevance and the physiological roles of human CHD, highlights the biochemical knowledge on the enzyme, and provides an analysis based on the comparison of the protein sequence with that of bacterial choline oxidase, for which structural and biochemical information is available.

  18. Glutamate dehydrogenase: structure, allosteric regulation, and role in insulin homeostasis.

    Science.gov (United States)

    Li, Ming; Li, Changhong; Allen, Aron; Stanley, Charles A; Smith, Thomas J

    2014-01-01

    Glutamate dehydrogenase (GDH) is a homohexameric enzyme that catalyzes the reversible oxidative deamination of L-glutamate to 2-oxoglutarate. Only in the animal kingdom is this enzyme heavily allosterically regulated by a wide array of metabolites. The major activators are ADP and leucine and inhibitors include GTP, palmitoyl CoA, and ATP. Spontaneous mutations in the GTP inhibitory site that lead to the hyperinsulinism/hyperammonemia (HHS) syndrome have shed light as to why mammalian GDH is so tightly regulated. Patients with HHS exhibit hypersecretion of insulin upon consumption of protein and concomitantly extremely high levels of ammonium in the serum. The atomic structures of four new inhibitors complexed with GDH complexes have identified three different allosteric binding sites. Using a transgenic mouse model expressing the human HHS form of GDH, at least three of these compounds blocked the dysregulated form of GDH in pancreatic tissue. EGCG from green tea prevented the hyper-response to amino acids in whole animals and improved basal serum glucose levels. The atomic structure of the ECG-GDH complex and mutagenesis studies is directing structure-based drug design using these polyphenols as a base scaffold. In addition, all of these allosteric inhibitors are elucidating the atomic mechanisms of allostery in this complex enzyme.

  19. The structure and allosteric regulation of mammalian glutamate dehydrogenase.

    Science.gov (United States)

    Li, Ming; Li, Changhong; Allen, Aron; Stanley, Charles A; Smith, Thomas J

    2012-03-15

    Glutamate dehydrogenase (GDH) is a homohexameric enzyme that catalyzes the reversible oxidative deamination of l-glutamate to 2-oxoglutarate. Only in the animal kingdom is this enzyme heavily allosterically regulated by a wide array of metabolites. The major activators are ADP and leucine, while the most important inhibitors include GTP, palmitoyl CoA, and ATP. Recently, spontaneous mutations in the GTP inhibitory site that lead to the hyperinsulinism/hyperammonemia (HHS) syndrome have shed light as to why mammalian GDH is so tightly regulated. Patients with HHS exhibit hypersecretion of insulin upon consumption of protein and concomitantly extremely high levels of ammonium in the serum. The atomic structures of four new inhibitors complexed with GDH complexes have identified three different allosteric binding sites. Using a transgenic mouse model expressing the human HHS form of GDH, at least three of these compounds were found to block the dysregulated form of GDH in pancreatic tissue. EGCG from green tea prevented the hyper-response to amino acids in whole animals and improved basal serum glucose levels. The atomic structure of the ECG-GDH complex and mutagenesis studies is directing structure-based drug design using these polyphenols as a base scaffold. In addition, all of these allosteric inhibitors are elucidating the atomic mechanisms of allostery in this complex enzyme.

  20. Priapism and glucose-6-phosphate dehydrogenase deficiency: An underestimated correlation?

    Directory of Open Access Journals (Sweden)

    Aldo Franco De Rose

    2016-10-01

    Full Text Available Priapism is a rare clinical condition characterized by a persistent erection unrelated to sexual excitement. Often the etiology is idiopathic. Three cases of priapism in glucose-6-phosphate dehydrogenase (G6PD deficiency patients have been described in literature. We present the case of a 39-year-old man with glucose- 6-phosphate dehydrogenase deficiency, who reached out to our department for the arising of a non-ischemic priapism without arteriolacunar fistula. We suggest that the glucose-6-phosphate dehydrogenase deficiency could be an underestimated risk factor for priapism.

  1. Pcal_1699, an extremely thermostable malate dehydrogenase from hyperthermophilic archaeon Pyrobaculum calidifontis.

    Science.gov (United States)

    Gharib, Ghazaleh; Rashid, Naeem; Bashir, Qamar; Gardner, Qura-Tul Ann Afza; Akhtar, Muhammad; Imanaka, Tadayuki

    2016-01-01

    Two malate dehydrogenase homologs, Pcal_0564 and Pcal_1699, have been found in the genome of Pyrobaculum calidifontis. The gene encoding Pcal_1699 consisted of 927 nucleotides corresponding to a polypeptide of 309 amino acids. To examine the properties of Pcal_1699, the structural gene was cloned, expressed in Escherichia coli and the purified gene product was characterized. Pcal_1699 was NADH specific enzyme exhibiting a high malate dehydrogenase activity (886 U/mg) at optimal pH (10) and temperature (90 °C). Unfolding studies suggested that urea could not induce complete unfolding and inactivation of Pcal_1699 even at a final concentration of 8 M; however, in the presence of 4 M guanidine hydrochloride enzyme structure was unfolded with complete loss of enzyme activity. Thermostability experiments revealed that Pcal_1699 is the most thermostable malate dehydrogenase, reported to date, retaining more than 90 % residual activity even after heating for 6 h in boiling water.

  2. Acute overexpression of lactate dehydrogenase-A perturbs beta-cell mitochondrial metabolism and insulin secretion.

    Science.gov (United States)

    Ainscow, E K; Zhao, C; Rutter, G A

    2000-07-01

    Islet beta-cells express low levels of lactate dehydrogenase and have high glycerol phosphate dehydrogenase activity. To determine whether this configuration favors oxidative glucose metabolism via mitochondria in the beta-cell and is important for beta-cell metabolic signal transduction, we have determined the effects on glucose metabolism and insulin secretion of acute overexpression of the skeletal muscle isoform of lactate dehydrogenase (LDH)-A. Monitored in single MIN6 beta-cells, LDH hyperexpression (achieved by intranuclear cDNA microinjection or adenoviral infection) diminished the response to glucose of both phases of increases in mitochondrial NAD(P)H, as well as increases in mitochondrial membrane potential, cytosolic free ATP, and cystolic free Ca2+. These effects were observed at all glucose concentrations, but were most pronounced at submaximal glucose levels. Correspondingly, adenoviral vector-mediated LDH-A overexpression reduced insulin secretion stimulated by 11 mmol/l glucose and the subsequent response to stimulation with 30 mmol/l glucose, but it was without significant effect when the concentration of glucose was raised acutely from 3 to 30 mmol/l. Thus, overexpression of LDH activity interferes with normal glucose metabolism and insulin secretion in the islet beta-cell type, and it may therefore be directly responsible for insulin secretory defects in some forms of type 2 diabetes. The results also reinforce the view that glucose-derived pyruvate metabolism in the mitochondrion is critical for glucose-stimulated insulin secretion in the beta-cell.

  3. Pharmacological Blockade of Cannabinoid CB1 Receptors in Diet-Induced Obesity Regulates Mitochondrial Dihydrolipoamide Dehydrogenase in Muscle.

    Science.gov (United States)

    Arrabal, Sergio; Lucena, Miguel Angel; Canduela, Miren Josune; Ramos-Uriarte, Almudena; Rivera, Patricia; Serrano, Antonia; Pavón, Francisco Javier; Decara, Juan; Vargas, Antonio; Baixeras, Elena; Martín-Rufián, Mercedes; Márquez, Javier; Fernández-Llébrez, Pedro; De Roos, Baukje; Grandes, Pedro; Rodríguez de Fonseca, Fernando; Suárez, Juan

    2015-01-01

    Cannabinoid CB1 receptors peripherally modulate energy metabolism. Here, we investigated the role of CB1 receptors in the expression of glucose/pyruvate/tricarboxylic acid (TCA) metabolism in rat abdominal muscle. Dihydrolipoamide dehydrogenase (DLD), a flavoprotein component (E3) of α-ketoacid dehydrogenase complexes with diaphorase activity in mitochondria, was specifically analyzed. After assessing the effectiveness of the CB1 receptor antagonist AM251 (3 mg kg(-1), 14 days) on food intake and body weight, we could identified seven key enzymes from either glycolytic pathway or TCA cycle--regulated by both diet and CB1 receptor activity--through comprehensive proteomic approaches involving two-dimensional electrophoresis and MALDI-TOF/LC-ESI trap mass spectrometry. These enzymes were glucose 6-phosphate isomerase (GPI), triosephosphate isomerase (TPI), enolase (Eno3), lactate dehydrogenase (LDHa), glyoxalase-1 (Glo1) and the mitochondrial DLD, whose expressions were modified by AM251 in hypercaloric diet-induced obesity. Specifically, AM251 blocked high-carbohydrate diet (HCD)-induced expression of GPI, TPI, Eno3 and LDHa, suggesting a down-regulation of glucose/pyruvate/lactate pathways under glucose availability. AM251 reversed the HCD-inhibited expression of Glo1 and DLD in the muscle, and the DLD and CB1 receptor expression in the mitochondrial fraction. Interestingly, we identified the presence of CB1 receptors at the membrane of striate muscle mitochondria. DLD over-expression was confirmed in muscle of CB1-/- mice. AM251 increased the pyruvate dehydrogenase and glutathione reductase activity in C2C12 myotubes, and the diaphorase/oxidative activity in the mitochondria fraction. These results indicated an up-regulation of methylglyoxal and TCA cycle activity. Findings suggest that CB1 receptors in muscle modulate glucose/pyruvate/lactate pathways and mitochondrial oxidative activity by targeting DLD.

  4. Pharmacological Blockade of Cannabinoid CB1 Receptors in Diet-Induced Obesity Regulates Mitochondrial Dihydrolipoamide Dehydrogenase in Muscle.

    Directory of Open Access Journals (Sweden)

    Sergio Arrabal

    Full Text Available Cannabinoid CB1 receptors peripherally modulate energy metabolism. Here, we investigated the role of CB1 receptors in the expression of glucose/pyruvate/tricarboxylic acid (TCA metabolism in rat abdominal muscle. Dihydrolipoamide dehydrogenase (DLD, a flavoprotein component (E3 of α-ketoacid dehydrogenase complexes with diaphorase activity in mitochondria, was specifically analyzed. After assessing the effectiveness of the CB1 receptor antagonist AM251 (3 mg kg(-1, 14 days on food intake and body weight, we could identified seven key enzymes from either glycolytic pathway or TCA cycle--regulated by both diet and CB1 receptor activity--through comprehensive proteomic approaches involving two-dimensional electrophoresis and MALDI-TOF/LC-ESI trap mass spectrometry. These enzymes were glucose 6-phosphate isomerase (GPI, triosephosphate isomerase (TPI, enolase (Eno3, lactate dehydrogenase (LDHa, glyoxalase-1 (Glo1 and the mitochondrial DLD, whose expressions were modified by AM251 in hypercaloric diet-induced obesity. Specifically, AM251 blocked high-carbohydrate diet (HCD-induced expression of GPI, TPI, Eno3 and LDHa, suggesting a down-regulation of glucose/pyruvate/lactate pathways under glucose availability. AM251 reversed the HCD-inhibited expression of Glo1 and DLD in the muscle, and the DLD and CB1 receptor expression in the mitochondrial fraction. Interestingly, we identified the presence of CB1 receptors at the membrane of striate muscle mitochondria. DLD over-expression was confirmed in muscle of CB1-/- mice. AM251 increased the pyruvate dehydrogenase and glutathione reductase activity in C2C12 myotubes, and the diaphorase/oxidative activity in the mitochondria fraction. These results indicated an up-regulation of methylglyoxal and TCA cycle activity. Findings suggest that CB1 receptors in muscle modulate glucose/pyruvate/lactate pathways and mitochondrial oxidative activity by targeting DLD.

  5. Cloning and functions analysis of a pyruvate dehydrogenase kinase in Brassica napus.

    Science.gov (United States)

    Li, Rong-Jun; Hu, Zhi-Yong; Zhang, Hua-Shan; Zhan, Gao-Miao; Wang, Han-Zhong; Hua, Wei

    2011-08-01

    Pyruvate dehydrogenase kinase (PDK) is a negative regulator of the mitochondrial pyruvate dehydrogenase complex (mtPDC), which plays a key role in intermediary metabolism. In this study, a 1,490-bp PDK in Brassica napus (BnPDK1) was isolated and cloned from Brassica cDNA library. BnPDK1 has an 1,104 open reading frame encoding 367 amino acids. Genomic DNA gel blot analysis result indicated that BnPDK1 is a multi-copy gene. RNA gel blot analysis and RNA in situ hybridization were used to determine the expression of BnPDK1 in different organs. BnPDK1 gene was ubiquitously expressed in almost all the tissues tested, having the highest expression in the stamen and the young silique. Over-expression of BnPDK1 in transgenic Arabidopsis lines would repress the PDC activity, and resulted in the decrease of seed oil content and leaf photosynthesis. These results implied that BnPDK1 was involved in the regulation of fatty acid biosynthesis in developing seeds.

  6. Prognostic values of aldehyde dehydrogenase 1 isoenzymes in ovarian cancer

    Directory of Open Access Journals (Sweden)

    Ma YM

    2016-04-01

    Full Text Available Yu-mei Ma,1 Shan Zhao2 1Department of Pathology, 2Department of Cancer Second Division, The Second Hospital of Hebei Medical University, Shijiazhuang City, People’s Republic of China Abstract: Aldehyde dehydrogenase 1 (ALDH1 activity has been used as a functional stem cell marker to isolate cancer stem cells in different cancer types, including ovarian cancer. However, which ALDH1’s isoenzymes are contributing to ALDH1 activity in ovarian cancer remains elusive. In addition, the prognostic value of an individual ALDH1 isoenzyme in ovarian cancer is not clear. Thus, we accessed the prognostic value of ALDH1 isoenzymes in ovarian cancer patients through the “Kaplan–Meier plotter” online database, which can be used to determine the effect of the genes on ovarian cancer prognosis. We found that high mRNA expression of five ALDH1 isoenzymes, such as ALDH1A1, ALDH1A2, ALDH1A3, ALDH1B1, and ALDH1L1, was not correlated with overall survival (OS for all 1,306 ovarian cancer patients. In addition, all five of the ALDH1 isoenzymes’ high mRNA expression was found to be uncorrelated with OS in serous cancer or endometrioid cancer patients. However, ALDH1A3’s high mRNA expression is associated with worse OS in grade II ovarian cancer patients, hazard ratio (HR 1.53 (1.14–2.07, P=0.005. ALDH1A2’s high mRNA expression is significantly associated with worse OS in TP53 wild-type ovarian cancer patients, HR 2.86 (1.56–5.08, P=0.00036. In addition, ALDH1A3’s high mRNA expression is significantly associated with better OS in TP53 wild-type ovarian cancer patients, HR 0.56 (0.32–1.00, P=0.04. Our results indicate that although ALDH1 isoenzyme mRNA might not be a prognostic marker for overall ovarian cancer patients, some isoenzymes, such as ALDH1A2 and ALDH1A3, might be a good prognostic marker for some types of ovarian cancer patients. Keywords: ALDH1, cancer stem cell, prognosis, KM plotter, hazard ratio

  7. Malate dehydrogenases from actinomycetes: structural comparison of Thermoactinomyces enzyme with other actinomycete and Bacillus enzymes.

    OpenAIRE

    1984-01-01

    Malate dehydrogenases from bacteria belonging to the genus Thermoactinomyces are tetrameric, like those from Bacillus spp., and exhibit a high degree of structural homology to Bacillus malate dehydrogenase as judged by immunological cross-reactivity. Malate dehydrogenases from other actinomycetes are dimers and do not cross-react with antibodies to Bacillus malate dehydrogenase.

  8. Immunochemical properties of NAD+-linked glycerol dehydrogenases from Escherichia coli and Klebsiella pneumoniae.

    OpenAIRE

    Tang, J C; Forage, R G; Lin, E C

    1982-01-01

    An NAD+-linked glycerol dehydrogenase hyperproduced by a mutant of Escherichia coli K-12 was found to be immunochemically homologous to a minor glycerol dehydrogenase of unknown physiological function in Klebsiella pneumoniae 1033, but not to the glycerol dehydrogenase of the dha system responsible for anaerobic dissimilation of glycerol or to the 2,3-butanediol dehydrogenase of K. pneumoniae.

  9. 21 CFR 862.1380 - Hydroxybutyric dehydrogenase test system.

    Science.gov (United States)

    2010-04-01

    ... dehydrogenase (HBD) in plasma or serum. HBD measurements are used in the diagnosis and treatment of myocardial infarction, renal damage (such as rejection of transplants), certain hematological diseases (such as...

  10. Genetics Home Reference: glucose-6-phosphate dehydrogenase deficiency

    Science.gov (United States)

    ... enzyme is involved in the normal processing of carbohydrates. It also protects red blood cells from the ... of glucose-6-phosphate dehydrogenase or alter its structure, this enzyme can no longer play its protective ...

  11. A novel glutamate dehydrogenase from bovine brain: purification and characterization.

    Science.gov (United States)

    Lee, J; Kim, S W; Cho, S W

    1995-08-01

    A soluble form of novel glutamate dehydrogenase has been purified from bovine brain. The preparation was homogeneous on sodium dodecyl sulfate-polyacrylamide gel electrophoresis and composed of six identical subunits having a subunit size of 57,500 Da. The biochemical properties of glutamate dehydrogenase such as N-terminal amino acids sequences, kinetic parameters, amino acids analysis, and optimum pH were examined in both reductive amination of alpha-ketoglutarate and oxidative deamination of glutamate. N-terminal amino acid sequences of the bovine brain enzyme showed the significant differences in the first 5 amino acids compared to other glutamate dehydrogenases from various sources. These results indicate that glutamate dehydrogenase isolated from bovine brain is a novel polypeptide.

  12. Formaldehyde degradation in Corynebacterium glutamicum involves acetaldehyde dehydrogenase and mycothiol-dependent formaldehyde dehydrogenase.

    Science.gov (United States)

    Lessmeier, Lennart; Hoefener, Michael; Wendisch, Volker F

    2013-12-01

    Corynebacterium glutamicum, a Gram-positive soil bacterium belonging to the actinomycetes, is able to degrade formaldehyde but the enzyme(s) involved in this detoxification process were not known. Acetaldehyde dehydrogenase Ald, which is essential for ethanol utilization, and FadH, characterized here as NAD-linked mycothiol-dependent formaldehyde dehydrogenase, were shown to be responsible for formaldehyde oxidation since a mutant lacking ald and fadH could not oxidize formaldehyde resulting in the inability to grow when formaldehyde was added to the medium. Moreover, C. glutamicum ΔaldΔfadH did not grow with vanillate, a carbon source giving rise to intracellular formaldehyde. FadH from C. glutamicum was purified from recombinant Escherichia coli and shown to be active as a homotetramer. Mycothiol-dependent formaldehyde oxidation revealed Km values of 0.6 mM for mycothiol and 4.3 mM for formaldehyde and a Vmax of 7.7 U mg(-1). FadH from C. glutamicum also possesses zinc-dependent, but mycothiol-independent alcohol dehydrogenase activity with a preference for short chain primary alcohols such as ethanol (Km = 330 mM, Vmax = 9.6 U mg(-1)), 1-propanol (Km = 150 mM, Vmax = 5 U mg(-1)) and 1-butanol (Km = 50 mM, Vmax = 0.8 U mg(-1)). Formaldehyde detoxification system by Ald and mycothiol-dependent FadH is essential for tolerance of C. glutamicum to external stress by free formaldehyde in its habitat and for growth with natural substrates like vanillate, which are metabolized with concomitant release of formaldehyde.

  13. Lactic dehydrogenase and cancer: an overview.

    Science.gov (United States)

    Gallo, Monica; Sapio, Luigi; Spina, Annamaria; Naviglio, Daniele; Calogero, Armando; Naviglio, Silvio

    2015-01-01

    Despite the intense scientific efforts made, there are still many tumors that are difficult to treat and the percentage of patient survival in the long-term is still too low. Thus, new approaches to the treatment of cancer are needed. Cancer is a highly heterogeneous and complex disease, whose development requires a reorganization of cell metabolism. Most tumor cells downregulate mitochondrial oxidative phosphorylation and increase the rate of glucose consumption and lactate release, independently of oxygen availability (Warburg effect). This metabolic rewiring is largely believed to favour tumor growth and survival, although the underlying molecular mechanisms are not completely understood. Importantly, the correlation between the aerobic glycolysis and cancer is widely regarded as a useful biochemical basis for the development of novel anticancer strategies. Among the enzymes involved in glycolysis, lactate dehydrogenase (LDH) is emerging as a very attractive target for possible pharmacological approaches in cancer therapy. This review addresses the state of the art and the perspectives concerning LDH both as a useful diagnostic marker and a relevant molecular target in cancer therapy and management.

  14. Resurrecting ancestral alcohol dehydrogenases from yeast.

    Science.gov (United States)

    Thomson, J Michael; Gaucher, Eric A; Burgan, Michelle F; De Kee, Danny W; Li, Tang; Aris, John P; Benner, Steven A

    2005-06-01

    Modern yeast living in fleshy fruits rapidly convert sugars into bulk ethanol through pyruvate. Pyruvate loses carbon dioxide to produce acetaldehyde, which is reduced by alcohol dehydrogenase 1 (Adh1) to ethanol, which accumulates. Yeast later consumes the accumulated ethanol, exploiting Adh2, an Adh1 homolog differing by 24 (of 348) amino acids. As many microorganisms cannot grow in ethanol, accumulated ethanol may help yeast defend resources in the fruit. We report here the resurrection of the last common ancestor of Adh1 and Adh2, called Adh(A). The kinetic behavior of Adh(A) suggests that the ancestor was optimized to make (not consume) ethanol. This is consistent with the hypothesis that before the Adh1-Adh2 duplication, yeast did not accumulate ethanol for later consumption but rather used Adh(A) to recycle NADH generated in the glycolytic pathway. Silent nucleotide dating suggests that the Adh1-Adh2 duplication occurred near the time of duplication of several other proteins involved in the accumulation of ethanol, possibly in the Cretaceous age when fleshy fruits arose. These results help to connect the chemical behavior of these enzymes through systems analysis to a time of global ecosystem change, a small but useful step towards a planetary systems biology.

  15. Liver alcohol dehydrogenase immobilized on polyvinylidene difluoride.

    Science.gov (United States)

    Roig, M G; Bello, J F; Moreno de Vega, M A; Cachaza, J M; Kennedy, J F

    1990-01-01

    A physical method for immobilization of liver alcohol dehydrogenase (ADH) by hydrophobic adsorption onto a supporting membrane of polyvinylidene difluoride (PVDF) was performed. Simultaneously, a physicochemical characterization of the immobilized enzyme regarding its kinetic behaviour was performed. The activity/pH profile observed points to an effect of pH on activity that is completely different from the case of ADH in solution. The disturbance in the typical bell-shaped profile owing to the fact that the enzyme was immobilized is explained on the basis of a potent limitation to the diffusion of the protons in the support. The findings of the present work also reveal the existence of an effect that limits free external diffusion of the substrate towards and/or the product from the support; this effect seems to be the determinant of the overall rate of the enzymatic reaction and is thus of great importance in the effective kinetic behaviour (v([S])) of immobilized ADH, whose kinetic behaviour is complex (non-Michaelian), as may be seen from the lack of linearity observed in the corresponding double reciprocal and Eadie-Hofstee plots. By non-linear regression numerical analysis of the v([S]) data and application of the F-test for model discrimination, the minimum rate equation necessary to describe the intrinsic kinetic behaviour of PVDF-immobilized ADH proved to be one of the polynomial quotient type of degree 2:2 (in substrate concentration).

  16. COMPUTATIONAL STUDIES OF THE KINETIC ISOTOPE EFFECT INMETHYLAMINE DEHYDROGENASE

    OpenAIRE

    Kopec-Harding, Kamilla Rosa

    2012-01-01

    There is currently experimental evidence of hydrogen tunnelling in over 20 different enzymes include yeast alcohol dehydrogenase (YADH), morphinone reductase (MR) and methylamine dehydrogenase (MADH). Various models have been used to describe hydrogen tunnelling in enzymes including the static barrier model, the vibrationally enhanced ground state tunnelling model (VEGST) and the environmentally coupled tunnelling model (ECT). Despite some differences in these models, there is a general cons...

  17. Dehydrogenase isoenzyme polymorphism in genus Prunus, subgenus Cerasus

    Directory of Open Access Journals (Sweden)

    Čolić Slavica

    2012-01-01

    Full Text Available Dehydrogenase polymorphism was studied in 36 sour cherry (Prunus cerasus L., sweet cherry (Prunus avuim L., mahaleb (Prunus mahaleb L., ground cherry (Prunus fruticosa Pall., duke cherry (Prunus gondounii Redh., Japanese flowering cherry (Prunus serrulata Lindl. and four iterspecific hybrids (standard cherry rootstocks ‘Gisela 5’, ‘Gisela 6’, ‘Max Ma’ and ‘Colt’. Inner bark of one-year-old shoots, in dormant stage, was used for enzyme extraction. Vertical PAGE was used for isoenzyme analysis: alcohol dehydrogenase (ADH, formate dehydrogenase (FDH, glutamate dehydrogenase (GDH, isocitrate dehydrogenaze (IDH, malate dehydrogenase (MDH, phosphogluconate dehydrogenase (PGD, and shikimate dehydrogenase (SDH. All studied systems were polymorphic at 10 loci: Adh -1 (3 genotypes and Adh-2 (5 genotypes, Fdh-1 (2 genotypes, Gdh-1 (3 genotypes, Idh-1 (4 genotypes i Idh -2 (5 genotypes, Mdh-1 (3 genotypes, Pgd-1 (4 genotypes, Sdh-1 (1 genotype i Sdh-2 (3 genotypes. Cluster analysis was used to construct dendrogram on which four groups of similar genotypes were separated. Obtained results indicate that studied enzyme systems can be used for determination of genus Prunus, subgenus Cerasus. Among studied enzyme systems ADH, IDH and SDH were the most polymorphic and most useful to identify genetic variability. Polymorphism of FDH and GDH in genus Prunus, subgenus Cerasus was described first time in this work. First results for dehydrogenase variability of Oblačinska indicate that polymorphism of loci Idh-2 and Sdh-2 can be useful for discrimination of different clones.

  18. Daidzin: a potent, selective inhibitor of human mitochondrial aldehyde dehydrogenase.

    OpenAIRE

    Keung, W M; Vallee, B L

    1993-01-01

    Human mitochondrial aldehyde dehydrogenase (ALDH-I) is potently, reversibly, and selectively inhibited by an isoflavone isolated from Radix puerariae and identified as daidzin, the 7-glucoside of 4',7-dihydroxyisoflavone. Kinetic analysis with formaldehyde as substrate reveals that daidzin inhibits ALDH-I competitively with respect to formaldehyde with a Ki of 40 nM, and uncompetitively with respect to the coenzyme NAD+. The human cytosolic aldehyde dehydrogenase isozyme (ALDH-II) is nearly 3...

  19. Molecular cloning, purification and immunogenicity of recombinant Brucella abortus 544 malate dehydrogenase protein.

    Science.gov (United States)

    Reyes, Alisha Wehdnesday Bernardo; Simborio, Hannah Leah Tadeja; Hop, Huynh Tan; Arayan, Lauren Togonon; Kim, Suk

    2016-03-01

    The Brucella mdh gene was successfully cloned and expressed in E. coli. The purified recombinant malate dehydrogenase protein (rMDH) was reactive to Brucella-positive bovine serum in the early stage, but not reactive in the middle or late stage, and was reactive to Brucella-positive mouse serum in the late stage, but not in the early or middle stage of infection. In addition, rMDH did not react with Brucella-negative bovine or mouse sera. These results suggest that rMDH has the potential for use as a specific antigen in serological diagnosis for early detection of bovine brucellosis.

  20. Arabidopsis mutant analysis and gene regulation define a nonredundant role for glutamate dehydrogenase in nitrogen assimilation.

    OpenAIRE

    Melo-Oliveira, R; I.C. Oliveira; Coruzzi, G M

    1996-01-01

    Glutamate dehydrogenase (GDH) is ubiquitous to all organisms, yet its role in higher plants remains enigmatic. To better understand the role of GDH in plant nitrogen metabolism, we have characterized an Arabidopsis mutant (gdh1-1) defective in one of two GDH gene products and have studied GDH1 gene expression. GDH1 mRNA accumulates to highest levels in dark-adapted or sucrose-starved plants, and light or sucrose treatment each repress GDH1 mRNA accumulation. These results suggest that the GDH...

  1. Enzymatic Kinetic Properties of the Lactate Dehydrogenase Isoenzyme C4 of the Plateau Pika (Ochotona curzoniae

    Directory of Open Access Journals (Sweden)

    Yang Wang

    2016-01-01

    Full Text Available Testis-specific lactate dehydrogenase (LDH-C4 is one of the lactate dehydrogenase (LDH isozymes that catalyze the terminal reaction of pyruvate to lactate in the glycolytic pathway. LDH-C4 in mammals was previously thought to be expressed only in spermatozoa and testis and not in other tissues. Plateau pika (Ochotona curzoniae belongs to the genus Ochotona of the Ochotonidea family. It is a hypoxia-tolerant species living in remote mountain areas at altitudes of 3000–5000 m above sea level on the Qinghai-Tibet Plateau. Surprisingly, Ldh-c is expressed not only in its testis and sperm, but also in somatic tissues of plateau pika. To shed light on the function of LDH-C4 in somatic cells, Ldh-a, Ldh-b, and Ldh-c of plateau pika were subcloned into bacterial expression vectors. The pure enzymes of Lactate Dehydrogenase A4 (LDH-A4, Lactate Dehydrogenase B4 (LDH-B4, and LDH-C4 were prepared by a series of expression and purification processes, and the three enzymes were identified by the method of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE and native polyacrylamide gel electrophoresis (PAGE. The enzymatic kinetics properties of these enzymes were studied by Lineweaver-Burk double-reciprocal plots. The results showed the Michaelis constant (Km of LDH-C4 for pyruvate and lactate was 0.052 and 4.934 mmol/L, respectively, with an approximate 90 times higher affinity of LDH-C4 for pyruvate than for lactate. At relatively high concentrations of lactate, the inhibition constant (Ki of the LDH isoenzymes varied: LDH-A4 (Ki = 26.900 mmol/L, LDH-B4 (Ki = 23.800 mmol/L, and LDH-C4 (Ki = 65.500 mmol/L. These data suggest that inhibition of lactate by LDH-A4 and LDH-B4 were stronger than LDH-C4. In light of the enzymatic kinetics properties, we suggest that the plateau pika can reduce reliance on oxygen supply and enhance its adaptation to the hypoxic environments due to increased anaerobic glycolysis by LDH-C4.

  2. Association between common alcohol dehydrogenase gene (ADH) variants and schizophrenia and autism

    OpenAIRE

    Zuo, Lingjun; Wang,Kesheng; Zhang, Xiang-Yang; Pan, Xinghua; Wang, Guilin; Tan, Yunlong; ZHONG, CHUNLONG; Krystal, John H.; State, Matthew; Zhang, Heping; Luo, Xingguang

    2013-01-01

    Humans express at least seven alcohol dehydrogenase (ADH) isoforms that are encoded by ADH gene cluster (ADH7–ADH1C–ADH1B–ADH1A–ADH6–ADH4–ADH5) at chromosome 4. ADHs are key catabolic enzymes for retinol and ethanol. The functional ADH variants (mostly rare) have been implicated in alcoholism risk. In addition to catalyzing the oxidation of retinol and ethanol, ADHs may be involved in the metabolic pathways of several neurotransmitters that are implicated in the neurobiology of neuropsychiatr...

  3. Very long-chain acyl CoA dehydrogenase deficiency which was accepted as infanticide.

    Science.gov (United States)

    Eminoglu, Tuba F; Tumer, Leyla; Okur, Ilyas; Ezgu, Fatih S; Biberoglu, Gursel; Hasanoglu, Alev

    2011-07-15

    Very-long-chain acyl-coenzyme A (CoA) dehydrogenase deficiency (VLCADD) (OMIM #201475) is an autosomal recessive disorder of fatty acid oxidation. Major phenotypic expressions are hypoketotic hypoglycemia, hepatomegaly, cardiomyopathy, myopathy, rhabdomyolysis, elevated creatinine kinase, and lipid infiltration of liver and muscle. At the same time, it is a rare cause of Sudden Infant Death Syndrome (SIDS) or unexplained death in the neonatal period [1-4]. We report a patient with VLCADD whose parents were investigated for infanticide because her three previous siblings had suddenly died after normal deliveries.

  4. Rutin attenuates ethanol-induced neurotoxicity in hippocampal neuronal cells by increasing aldehyde dehydrogenase 2.

    Science.gov (United States)

    Song, Kibbeum; Kim, Sokho; Na, Ji-Young; Park, Jong-Heum; Kim, Jae-Kyung; Kim, Jae-Hun; Kwon, Jungkee

    2014-10-01

    Rutin is derived from buckwheat, apples, and black tea. It has been shown to have beneficial anti-inflammatory and antioxidant effects. Ethanol is a central nervous system depressant and neurotoxin. Its metabolite, acetaldehyde, is critically toxic. Aldehyde dehydrogenase 2 (ALDH2) metabolizes acetaldehyde into nontoxic acetate. This study examined rutin's effects on ALDH2 activity in hippocampal neuronal cells (HT22 cells). Rutin's protective effects against acetaldehyde-based ethanol neurotoxicity were confirmed. Daidzin, an ALDH2 inhibitor, was used to clarify the mechanisms of rutin's protective effects. Cell viability was significantly increased after rutin treatment. Rutin significantly reversed ethanol-increased Bax, cytochrome c expression and caspase 3 activity, and decreased Bcl-2 and Bcl-xL protein expression in HT22 cells. Interestingly, rutin increased ALDH2 expression, while daidzin reversed this beneficial effect. Thus, this study demonstrates rutin protects HT22 cells against ethanol-induced neurotoxicity by increasing ALDH2 activity.

  5. Properties and subunit structure of pig heart pyruvate dehydrogenase.

    Science.gov (United States)

    Hamada, M; Hiraoka, T; Koike, K; Ogasahara, K; Kanzaki, T

    1976-06-01

    Pyruvate dehydrogenase [EC 1.2.4.1] was separated from the pyruvate dehydrogenase complex and its molecular weight was estimated to be about 150,000 by sedimentation equilibrium methods. The enzyme was dissociated into two subunits (alpha and beta), with estimated molecular weights of 41,000 (alpha) and 36,000 (beta), respectively, by polyacrylamide gel electrophoresis in sodium dodecyl sulfate. The subunits were separated by phosphocellulose column chromatography and their chemical properties were examined. The subunit structure of the pyruvate dehydrogenase was assigned as alpha2beta2. The content of right-handed alpha-helix in the enzyme molecule was estimated to be about 29 and 28% by optical rotatory dispersion and by circular dichroism, respectively. The enzyme contained no thiamine-PP, and its dehydrogenase activity was completely dependent on added thiamine-PP and partially dependent on added Mg2+ and Ca2+. The Km value of pyruvate dehydrogenase for thiamine diphosphate was estimated to be 6.5 X 10(-5) M in the presence of Mg2+ or Ca2+. The enzyme showed highly specific activity for thiamine-PP dependent oxidation of both pyruvate and alpha-ketobutyrate, but it also showed some activity with alpha-ketovalerate, alpha-ketoisocaproate, and alpha-ketoisovalerate. The pyruvate dehydrogenase activity was strongly inhibited by bivalent heavy metal ions and by sulfhydryl inhibitors; and the enzyme molecule contained 27 moles of 5,5'-dithiobis(2-nitrobenzoic acid)-reactive sulfhydryl groups and a total of 36 moles of sulfhydryl groups. The inhibitory effect of p-chloromercuribenzoate was prevented by preincubating the enzyme with thiamine-PP plus pyruvate. The structure of pyruvate dehydrogenase necessary for formation of the complex is also reported.

  6. Retinol dehydrogenase, RDH1l, is essential for the heart development and cardiac performance in zebrafish

    Institute of Scientific and Technical Information of China (English)

    WANG Wei; ZHANG Li-feng; GUI Yong-hao; SONG Hou-yan

    2013-01-01

    Background Retinoic acid (RA) is a potent signaling molecule that plays pleiotropic roles in patterning,morphogenesis,and organogenesis during embryonic development.The synthesis from retinol (vitamin A) to retinoic acid requires two sequential oxidative steps.The first step involves the oxidation of retinol to retinal through the action of retinol dehydrogenases.Retinol dehydrogenases1l (RDH1l) is a novel zebrafish retinol dehydrogenase.Herein we investigated the role of zebrafish RDH1l in heart development and cardiac performance in detail.Methods RDH1l specific morpholino was used to reduce the function of RDH1l in zebrafish.The gene expressions were observed by using whole mount in situ hybridization.Heart rates were observed and recorded under the microscope from 24 to 72 hours post fertilization (hpf).The cardiac performance was analyzed by measuring ventricular shortening fraction (VSF).Results The knock-down of RDH1l led to abnormal neural crest cells migration and reduced numbers of neural crest cells in RDH1l morphant embryos.The reduced numbers of cardiac neural crest cells also can be seen in RDH1l morphant embryos.Furthermore,the morpholino-mediated knock-down of RDH1l resulted in the abnormal heart loop.The left-right determining genes expression pattern was altered in RDH1l morphant embryos.The impaired cardiac performance was observed in RDH1l morphant embryos.Taken together,these data demonstrate that RDH1l is essential for the heart development and cardiac performance in zebrafish.Conclusions RDH1l plays a important role in the neural crest cells development,and then ultimately affects the heart loop and cardiac performance.These results show for the first time that an enzyme involved in the retinol to retinaldehyde conversion participate in the heart development and cardiac performance in zebrafish.

  7. Suppression of cellulase and polygalacturonase and induction of alcohol dehydrogenase isoenzymes in avocado fruit mesocarp subjected to low oxygen stress.

    Science.gov (United States)

    Kanellis, A K; Solomos, T; Roubelakis-Angelakis, K A

    1991-05-01

    Expression of polygalacturonase and cellulase, two hydrolytic enzymes of avocado (Persea americana, cv Hass) fruit which are synthesized de novo during ripening, and alcohol dehydrogenase, a known anaerobic protein, were studied under different O(2) regimes. Low O(2) concentrations (2.5-5.5%) diminished the accumulation of polygalacturonase and cellulase proteins and the expression of their isoenzymes. This pattern of change in cellulase protein was also reflected in the steady-state amount of its mRNA. In contrast, 7.5 and 10% O(2) did not alter the changes observed in fruits ripened in air. On the other hand, alcohol dehydrogenase was induced in 2.5, 3.5, and 5.5% O(2) but not in 7.5 or 10% O(2). The recovery from the hypoxic stress upon returning the fruits back to air for 24 hours, was also a function of O(2) tensions under which the fruits were kept. Thus, the synthesis of polygalacturonase and cellulase was directly related to O(2) levels, while the activity of the isoenzymes of alcohol dehydrogenase was inversely related to O(2) levels. The results indicate that hypoxia exerts both negative and positive effects on the expression of certain genes and that these effects are initiated at the same levels of O(2).

  8. Identification of Hedgehog pathway responsive glioblastomas by isocitrate dehydrogenase mutation.

    Science.gov (United States)

    Gerardo Valadez, J; Grover, Vandana K; Carter, Melissa D; Calcutt, M Wade; Abiria, Sunday A; Lundberg, Christopher J; Williams, Thomas V; Cooper, Michael K

    2013-01-28

    The Hedgehog (Hh) pathway regulates the growth of a subset of adult gliomas and better definition of Hh-responsive subtypes could enhance the clinical utility of monitoring and targeting this pathway in patients. Somatic mutations of the isocitrate dehydrogenase (IDH) genes occur frequently in WHO grades II and III gliomas and WHO grade IV secondary glioblastomas. Hh pathway activation in WHO grades II and III gliomas suggests that it might also be operational in glioblastomas that developed from lower-grade lesions. To evaluate this possibility and to better define the molecular and histopathological glioma subtypes that are Hh-responsive, IDH genes were sequenced in adult glioma specimens assayed for an operant Hh pathway. The proportions of grades II-IV specimens with IDH mutations correlated with the proportions that expressed elevated levels of the Hh gene target PTCH1. Indices of an operational Hh pathway were measured in all primary cultures and xenografts derived from IDH-mutant glioma specimens, including IDH-mutant glioblastomas. In contrast, the Hh pathway was not operational in glioblastomas that lacked IDH mutation or history of antecedent lower-grade disease. IDH mutation is not required for an operant pathway however, as significant Hh pathway modulation was also measured in grade III gliomas with wild-type IDH sequences. These results indicate that the Hh pathway is operational in grades II and III gliomas and glioblastomas with molecular or histopathological evidence for evolvement from lower-grade gliomas. Lastly, these findings suggest that gliomas sharing this molecularly defined route of progression arise in Hh-responsive cell types.

  9. Interaction of carbohydrates with alcohol dehydrogenase: Effect on enzyme activity.

    Science.gov (United States)

    Jadhav, Swati B; Bankar, Sandip B; Granström, Tom; Ojamo, Heikki; Singhal, Rekha S; Survase, Shrikant A

    2015-09-01

    Alcohol dehydrogenase was covalently conjugated with three different oxidized carbohydrates i.e., glucose, starch and pectin. All the carbohydrates inhibited the enzyme. The inhibition was studied with respect to the inhibition rate constant, involvement of thiol groups in the binding, and structural changes in the enzyme. The enzyme activity decreased to half of its original activity at the concentration of 2 mg/mL of pectin, 4 mg/mL of glucose and 10 mg/mL of starch within 10 min at pH 7. This study showed oxidized pectin to be a potent inhibitor of alcohol dehydrogenase followed by glucose and starch. Along with the aldehyde-amino group interaction, thiol groups were also involved in the binding between alcohol dehydrogenase and carbohydrates. The structural changes occurring on binding of alcohol dehydrogenase with oxidized carbohydrates was also confirmed by fluorescence spectrophotometry. Oxidized carbohydrates could thus be used as potential inhibitors of alcohol dehydrogenase.

  10. Characterization of interactions of dihydrolipoamide dehydrogenase with its binding protein in the human pyruvate dehydrogenase complex

    Energy Technology Data Exchange (ETDEWEB)

    Park, Yun-Hee [Department of Biochemistry, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY 14214 (United States); Patel, Mulchand S., E-mail: mspatel@buffalo.edu [Department of Biochemistry, School of Medicine and Biomedical Sciences, University at Buffalo, State University of New York, Buffalo, NY 14214 (United States)

    2010-05-07

    Unlike pyruvate dehydrogenase complexes (PDCs) from prokaryotes, PDCs from higher eukaryotes have an additional structural component, E3-binding protein (BP), for binding of dihydrolipoamide dehydrogenase (E3) in the complex. Based on the 3D structure of the subcomplex of human (h) E3 with the di-domain (L3S1) of hBP, the amino acid residues (H348, D413, Y438, and R447) of hE3 for binding to hBP were substituted singly by alanine or other residues. These substitutions did not have large effects on hE3 activity when measured in its free form. However, when these hE3 mutants were reconstituted in the complex, the PDC activity was significantly reduced to 9% for Y438A, 20% for Y438H, and 18% for D413A. The binding of hE3 mutants with L3S1 determined by isothermal titration calorimetry revealed that the binding affinities of the Y438A, Y438H, and D413A mutants to L3S1 were severely reduced (1019-, 607-, and 402-fold, respectively). Unlike wild-type hE3 the binding of the Y438A mutant to L3S1 was accompanied by an unfavorable enthalpy change and a large positive entropy change. These results indicate that hE3-Y438 and hE3-D413 play important roles in binding of hE3 to hBP.

  11. Cloning and Characterization of Glyceraldehyde-3-phosphate Dehydrogenase Encoding Gene in Gracilaria/Gracilariopsis lemaneiformis

    Institute of Scientific and Technical Information of China (English)

    REN Xueying; SUI Zhenghong; ZHANG Xuecheng

    2006-01-01

    Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) plays important roles in various cellular processes. A cytosolic GAPDH encoding gene (gpd) of Gracilaria/Gracilariopsis lemaneiformis was cloned and characterized. Deduced amino acid sequence of the enzyme of G. lemaneiformis had high homology with those of seven red algae. The 5'-untranslated regions of the GAPDHs encoding genes of these red algae varied greatly. GAPDHs of these red algae shared the highly conserved glyceraldehyde 3-phosphate dehydrogenase active site ASCTTNCL. However, such active site of Cyanidium caldarium was different from those of the other six algae at the last two residues (CL to LF), thus the spatial structure of its GAPDH active center may be different from those of the other six. Phylogenetic analysis indicated that GAPDH of G. lemaneiformis might have undergone an evolution similar to those of Porphyra yezoensis, Chondrus crispus, and Gracilaria verrucosa. C. caldarium had a closer evolutionary relationship with Cyanidioschyzon merolae than with Cyanidium sp. Virtual Northern blot analysis revealed that gpd of G. lemaneiformis expressed constitutively, which suggested that it might be house-keeping and could be adapted as an inner control in gene expression analysis of G. lemaneiformis.

  12. Biochemical and structural characterization of the apicoplast dihydrolipoamide dehydrogenase of Plasmodium falciparum.

    Science.gov (United States)

    Laine, Larissa M; Biddau, Marco; Byron, Olwyn; Müller, Sylke

    2015-01-14

    PDC (pyruvate dehydrogenase complex) is a multi-enzyme complex comprising an E1 (pyruvate decarboxylase), an E2 (dihydrolipomide acetyltransferase) and an E3 (dihydrolipoamide dehydrogenase). PDC catalyses the decarboxylation of pyruvate and forms acetyl-CoA and NADH. In the human malaria parasite Plasmodium falciparum, the single PDC is located exclusively in the apicoplast. Plasmodium PDC is essential for parasite survival in the mosquito vector and for late liver stage development in the human host, suggesting its suitability as a target for intervention strategies against malaria. Here, PfaE3 (P. falciparum apicoplast E3) was recombinantly expressed and characterized. Biochemical parameters were comparable with those determined for E3 from other organisms. A homology model for PfaE3 reveals an extra anti-parallel β-strand at the position where human E3BP (E3-binding protein) interacts with E3; a parasite-specific feature that may be exploitable for drug discovery against PDC. To assess the biological role of Pfae3, it was deleted from P. falciparum and although the mutants are viable, they displayed a highly synchronous growth phenotype during intra-erythrocytic development. The mutants also showed changes in the expression of some mitochondrial and antioxidant proteins suggesting that deletion of Pfae3 impacts on the parasite's metabolic function with downstream effects on the parasite's redox homoeostasis and cell cycle.

  13. Aminotransferase and glutamate dehydrogenase activities in lactobacilli and streptococci.

    Science.gov (United States)

    Peralta, Guillermo Hugo; Bergamini, Carina Viviana; Hynes, Erica Rut

    2016-01-01

    Aminotransferases and glutamate dehydrogenase are two main types of enzymes involved in the initial steps of amino acid catabolism, which plays a key role in the cheese flavor development. In the present work, glutamate dehydrogenase and aminotransferase activities were screened in twenty one strains of lactic acid bacteria of dairy interest, either cheese-isolated or commercial starters, including fifteen mesophilic lactobacilli, four thermophilic lactobacilli, and two streptococci. The strains of Streptococcus thermophilus showed the highest glutamate dehydrogenase activity, which was significantly elevated compared with the lactobacilli. Aspartate aminotransferase prevailed in most strains tested, while the levels and specificity of other aminotransferases were highly strain- and species-dependent. The knowledge of enzymatic profiles of these starter and cheese-isolated cultures is helpful in proposing appropriate combinations of strains for improved or increased cheese flavor.

  14. The Role of Pyruvate Dehydrogenase Kinase in Diabetes and Obesity

    Directory of Open Access Journals (Sweden)

    In-Kyu Lee

    2014-06-01

    Full Text Available The pyruvate dehydrogenase complex (PDC is an emerging target for the treatment of metabolic syndrome. To maintain a steady-state concentration of adenosine triphosphate during the feed-fast cycle, cells require efficient utilization of fatty acid and glucose, which is controlled by the PDC. The PDC converts pyruvate, coenzyme A (CoA, and oxidized nicotinamide adenine dinucleotide (NAD+ into acetyl-CoA, reduced form of nicotinamide adenine dinucleotide (NADH, and carbon dioxide. The activity of the PDC is up- and down-regulated by pyruvate dehydrogenase kinase and pyruvate dehydrogenase phosphatase, respectively. In addition, pyruvate is a key intermediate of glucose oxidation and an important precursor for the synthesis of glucose, glycerol, fatty acids, and nonessential amino acids.

  15. The activity of alcohol dehydrogenase (ADH) isoenzymes and aldehyde dehydrogenase (ALDH) in the sera of patients with brain cancer.

    Science.gov (United States)

    Jelski, Wojciech; Laniewska-Dunaj, Magdalena; Orywal, Karolina; Kochanowicz, Jan; Rutkowski, Robert; Szmitkowski, Maciej

    2014-12-01

    Human brain tissue contains various alcohol dehydrogenase (ADH) isoenzymes and possess also aldehyde dehydrogenase (ALDH) activity. In our last experiments we have shown that ADH and ALDH are present also in the brain tumour cells. Moreover the activities of total ADH and class I isoenzymes were significantly higher in cancer tissue than healthy cells. It can suggests that these changes may be reflected by enzyme activity in the serum of patients with brain cancer. Serum samples were taken for routine biochemical investigation from 62 patients suffering from brain cancer (36 glioblastoma, 26 meningioma). For the measurement of the activity of class I and II ADH isoenzymes and ALDH activity, the fluorometric methods were used. The total ADH activity and activity of class III and IV isoenzymes were measured by the photometric method. A statistically significant increase of class I alcohol dehydrogenase isoenzymes was found in the sera of patients with brain cancer. The median activity of this class isoenzyme in the patients group increased about 24 % in the comparison to the control level. The total alcohol dehydrogenase activity was also significantly higher (26 %) among patients with brain tumour than healthy ones. The activities of other tested ADH isoenzymes and total ALDH were unchanged. The increase of the activity of total ADH and class I alcohol dehydrogenase isoenzyme in the sera of patients with brain cancer seems to be caused by the release of this isoenzyme from tumour's cells.

  16. Crystal structure of homoisocitrate dehydrogenase from Schizosaccharomyces pombe

    Energy Technology Data Exchange (ETDEWEB)

    Bulfer, Stacie L.; Hendershot, Jenna M.; Trievel, Raymond C. (Michigan); (UCSF)

    2013-09-18

    Lysine biosynthesis in fungi, euglena, and certain archaebacteria occurs through the {alpha}-aminoadipate pathway. Enzymes in the first steps of this pathway have been proposed as potential targets for the development of antifungal therapies, as they are absent in animals but are conserved in several pathogenic fungi species, including Candida, Cryptococcus, and Aspergillus. One potential antifungal target in the {alpha}-aminoadipate pathway is the third enzyme in the pathway, homoisocitrate dehydrogenase (HICDH), which catalyzes the divalent metal-dependent conversion of homoisocitrate to 2-oxoadipate (2-OA) using nicotinamide adenine dinucleotide (NAD{sup +}) as a cofactor. HICDH belogns to a family of {beta}-hydroxyacid oxidative decarboxylases that includes malate dehydrogenase, tartrate dehydrogenase, 6-phosphogluconate dehydrogenase, isocitrate dehydrogenase (ICDH), and 3-isopropylmalte dehydrogenase (IPMDH). ICDH and IPMDH are well-characterized enzymes that catalyze the decarboxylation of isocitrate to yield 2-oxoglutarate (2-OG) in the citric acid cycle and the conversion of 3-isopropylmalate to 2-oxoisovalerate in the leucine biosynthetic pathway, respectively. Recent structural and biochemical studies of HICDH reveal that this enzyme shares sequence, structural, and mechanistic homology with ICDH and IPMDH. To date, the only published structures of HICDH are from the archaebacteria Thermus thermophilus (TtHICDH). Fungal HICDHs diverge from TtHICDH in several aspects, including their thermal stability, oligomerization state, and substrate specificity, thus warranting further characterization. To gain insights into these differences, they determined crystal structures of a fungal Schizosaccharomyces pombe HICDH (SpHICDH) as an apoenzyme and as a binary complex with additive tripeptide glycyl-glycyl-glycine (GGG) to 1.55 {angstrom} and 1.85 {angstrom} resolution, respectively. Finally, a comparison of the SpHICDH and TtHICDH structures reveal differences in

  17. Purification and characterization of 3-isopropylmalate dehydrogenase from Thiobacillus thiooxidans.

    Science.gov (United States)

    Kawaguchi, H; Inagaki, K; Matsunami, H; Nakayama, Y; Tano, T; Tanaka, H

    2000-01-01

    3-Isopropylmalate dehydrogenase was purified to homogeneity from the acidophilic autotroph Thiobacillus thiooxidans. The native enzyme was a dimer of molecular weight 40,000. The apparent K(m) values for 3-isopropylmalate and NAD+ were estimated to be 0.13 mM and 8.7 mM, respectively. The optimum pH for activity was 9.0 and the optimum temperature was 65 degrees C. The properties of the enzyme were similar to those of the Thiobacillus ferrooxidans enzyme, expect for substrate specificity. T. thiooxidans 3-isopropylmalate dehydrogenase could not utilize malate as a substrate.

  18. An L-glucitol oxidizing dehydrogenase from Bradyrhizobium japonicum USDA 110 for production of D-sorbose with enzymatic or electrochemical cofactor regeneration.

    Science.gov (United States)

    Gauer, Sabrina; Wang, Zhijie; Otten, Harm; Etienne, Mathieu; Bjerrum, Morten Jannik; Lo Leggio, Leila; Walcarius, Alain; Giffhorn, Friedrich; Kohring, Gert-Wieland

    2014-04-01

    A gene in Bradyrhizobium japonicum USDA 110, annotated as a ribitol dehydrogenase (RDH), had 87 % sequence identity (97 % positives) to the N-terminal 31 amino acids of an L-glucitol dehydrogenase from Stenotrophomonas maltophilia DSMZ 14322. The 729-bp long RDH gene coded for a protein consisting of 242 amino acids with a molecular mass of 26.1 kDa. The heterologously expressed protein not only exhibited the main enantio selective activity with D-glucitol oxidation to D-fructose but also converted L-glucitol to D-sorbose with enzymatic cofactor regeneration and a yield of 90 %. The temperature stability and the apparent K m value for L-glucitol oxidation let the enzyme appear as a promising subject for further improvement by enzyme evolution. We propose to rename the enzyme from the annotated RDH gene (locus tag bll6662) from B. japonicum USDA as a D-sorbitol dehydrogenase (EC 1.1.1.14).

  19. Characterization of an Arxula adeninivorans alcohol dehydrogenase involved in the metabolism of ethanol and 1-butanol.

    Science.gov (United States)

    Kasprzak, Jakub; Rauter, Marion; Riechen, Jan; Worch, Sebastian; Baronian, Kim; Bode, Rüdiger; Schauer, Frieder; Kunze, Gotthard

    2016-05-01

    In this study, alcohol dehydrogenase 1 from Arxula adeninivorans (Aadh1p) was identified and characterized. Aadh1p showed activity with short and medium chain length primary alcohols in the forward reaction and their aldehydes in the reverse reaction. Aadh1p has 64% identity with Saccharomyces cerevisiae Adh1p, is localized in the cytoplasm and uses NAD(+) as cofactor. Gene expression analysis showed a low level increase in AADH1 gene expression with ethanol, pyruvate or xylose as the carbon source. Deletion of the AADH1 gene affects growth of the cells with 1-butanol, ethanol and glucose as the carbon source, and a strain which overexpressed the AADH1 gene metabolized 1-butanol more rapidly. An ADH activity assay indicated that Aadh1p is a major enzyme for the synthesis of ethanol and the degradation of 1-butanol in A. adeninivorans.

  20. Molecular cloning and characterization of the glyceraldehyde-3-phosphate dehydrogenase gene from Penicillium expansum PE-12.

    Science.gov (United States)

    Zhang, T; Qi, Z; Yu, Q S; Tang, K X

    2013-07-15

    Penicillium expansum produces large amounts of lipase, which is widely used in laundry detergent and leather industry. We isolated the glyceraldehyde-3-phosphate dehydrogenase gene (PeGPD) from P. expansum PE-12 through reverse transcriptase PCR and 5'-3' rapid amplification of cDNA ends (RACE-PCR). The gene is 1266 bp long, including an ORF of 1014 bp, encoding a polypeptide chain of 337 amino acids. A phylogenetic tree based on GPD proteins showed that P. expansum is close to Aspergillus species, but comparatively distant from P. marneffei. Southern blot results revealed a single copy of PeGPD, and expression analysis gave evidence of high expression levels. PeGPD genes have potential for genetic engineering of P. expansum for industrial lipase production.

  1. NADP-dependent mannitol dehydrogenase, a major allergen of Cladosporium herbarum.

    Science.gov (United States)

    Simon-Nobbe, Birgit; Denk, Ursula; Schneider, Peter Bernhard; Radauer, Christian; Teige, Markus; Crameri, Reto; Hawranek, Thomas; Lang, Roland; Richter, Klaus; Schmid-Grendelmeier, Peter; Nobbe, Stephan; Hartl, Arnulf; Breitenbach, Michael

    2006-06-16

    Cladosporium herbarum is an important allergenic fungal species that has been reported to cause allergic diseases in nearly all climatic zones. 5-30% of the allergic population displays IgE antibodies against molds. Sensitization to Cladosporium has often been associated with severe asthma and less frequently with chronic urticaria and atopic eczema. However, no dominant major allergen of this species has been found so far. We present cloning, production, and characterization of NADP-dependent mannitol dehydrogenase of C. herbarum (Cla h 8) and show that this protein is a major allergen that is recognized by IgE antibodies of approximately 57% of all Cladosporium allergic patients. This is the highest percentage of patients reacting with any Cladosporium allergen characterized so far. Cla h 8 was purified to homogeneity by standard chromatographic methods, and both N-terminal and internal amino acid sequences of protein fragments were determined. Enzymatic analysis of the purified natural protein revealed that this allergen represents a NADP-dependent mannitol dehydrogenase that interconverts mannitol and d-fructose. It is a soluble, non-glycosylated cytoplasmic protein. Two-dimensional protein analysis indicated that mannitol dehydrogenase is present as a single isoform. The cDNA encoding Cla h 8 was cloned from a lambda-ZAP library constructed from hyphae and spores. The recombinant non-fusion protein was expressed in Escherichia coli and purified to homogeneity. Its immunological and biochemical identity with the natural protein was shown by enzyme activity tests, CD spectroscopy, IgE immunoblots with sera of patients, and by skin prick testing of Cladosporium allergic patients. This protein therefore is a new major allergen of C. herbarum.

  2. Comparison between medium-chain acyl-CoA dehydrogenase mutant proteins overexpressed in bacterial and mammalian cells

    DEFF Research Database (Denmark)

    Jensen, T G; Bross, P; Andresen, B S;

    1995-01-01

    Medium-chain acyl-CoA dehydrogenase (MCAD) deficiency is a potentially lethal inherited defect in the beta-oxidation of fatty acids. By comparing the behaviour of five missense MCAD mutant proteins expressed in COS cells and in Escherichia coli, we can define some of these as "pure folding mutants......." Upon expression in E. coli, these mutant proteins produce activity levels in the range of the wild-type enzyme only if the chaperonins GroESL are co-overproduced. When overexpressed in COS cells, the pure folding mutants display enzyme activities comparable to the wild-type enzyme. The results suggest...

  3. Sodium homeostasis is preserved in a global 11β-hydroxysteroid dehydrogenase type 1 knockout mouse model

    DEFF Research Database (Denmark)

    Christensen, Thorbjørn H; Bailey, Matthew A; Kenyon, Christopher J

    2015-01-01

    NEW FINDINGS: What is the central question of this study? Glucocorticoids act in the kidney to promote salt and water retention. Renal 11β-hydroxysteroid dehydrogenase type 1 (11βHSD1), by increasing local concentrations of glucocorticoids, may exert an antinatriuretic effect. We hypothesized...... that global deletion of 11βHSD1 in the mouse would give rise to a salt-wasting renal phenotype. What is the main finding and its importance? We subjected a mouse model of global 11βHSD1 deletion to studies of water and electrolyte balance, renal clearance, urinary steroid excretion, renin-angiotensin system...... sodium retention. 11β-Hydroxysteroid dehydrogenase type 1 (11βHSD1) is expressed in the renal tubules and the interstitial cells of the medulla, where it is likely to regenerate active glucocorticoids from inert 11-keto forms. The physiological function of renal 11βHSD1 is largely unknown. We...

  4. Polymorphisms of alcohol dehydrogenase 2 and aldehyde dehydrogenase 2 and colorectal cancer risk in Chinese males

    Institute of Scientific and Technical Information of China (English)

    Chang-Ming Gao; Keitaro Matsuo; Nobuyuki Hamajima; Kazuo Tajima; Toshiro Takezaki; Jian-Zhong Wu; Xiao-Mei Zhang; Hai-Xia Cao; Jian-Hua Ding; Yan-Ting Liu; Su-Ping Li; Jia Cao

    2008-01-01

    AIM: To evaluate the relationship between drinking and polymorphisms of alcohol dehydrogenase 2 (ADH2) and/or aldehyde dehydrogenase 2 (ALDH2) for risk of colorectal cancer (CRC) in Chinese males.METHODS: A case-control study was conducted in 190 cases and 223 population-based controls.ADH2 Arg47His (G-A) and ALDH2 Glu487Lys (G-A) genotypes were identified by PCR and denaturing high-performance liquid chromatography (DHPLC).Information on smoking and drinking was collected and odds ratio (OR) was estimated.RESULTS: The ADH2 A/A and ALDH2 G/G genotypes showed moderately increased CRC risk. The age- and smoking-adjusted OR for ADH2 A/A relative to G/A and G/G was 1.60 (95% CI=1.08-2.36), and the adjusted OR for ALDH2 G/G relative to G/A and A/A was 1.79 (95% CI=1.19-2.69). Significant interactions between ADH2,ALDH2 and drinking were observed. As compared to the subjects with ADH2 G and ALDH2 A alleles, those with ADH2 A/A and ALDH2 G/G genotypes had a significantly increased OR (3.05, 95% CI= 1.67-5.57). The OR for CRC among drinkers with the ,4DH2 A/A genotype was increased to 3.44 (95% CI= 1.84-6.42) compared with non-drinkers with the ADH2 G allele. The OR for CRC among drinkers with theALDH2 G/G genotype was also increased to 2.70 (95% CI= 1.57-4.66) compared with non-drinkers with the ALDH2 A allele.CONCLUSION: Polymorphisms of the ADH2 and ALDH2 genes are significantly associated with CRC risk. There are also significant gene-gene and geneenvironment interactions between drinking and ADH2 and ALDH2 polymorphisms regarding CRC risk in Chinese males.

  5. Malate dehydrogenase in phototrophic purple bacteria: purification, molecular weight, and quaternary structure.

    OpenAIRE

    1987-01-01

    The citric acid cycle enzyme malate dehydrogenase was purified to homogeneity from the nonsulfur purple bacteria Rhodobacter capsulatus, Rhodospirillum rubrum, Rhodomicrobium vannielii, and Rhodocyclus purpureus. Malate dehydrogenase was purified from each species by either a single- or a two-step protocol: triazine dye affinity chromatography was the key step in purification of malate dehydrogenase in all cases. Purification of malate dehydrogenase resulted in a 130- to 240-fold increase in ...

  6. Mutations associated with succinate dehydrogenase D-related malignant paragangliomas.

    NARCIS (Netherlands)

    Timmers, H.J.L.M.; Pacak, K.; Bertherat, J.; Lenders, J.W.M.; Duet, M.; Eisenhofer, G.; Stratakis, C.A.; Niccoli-Sire, P.; Tran, B.H.; Burnichon, N.; Gimenez-Roqueplo, A.P.

    2008-01-01

    OBJECTIVE: Hereditary paraganglioma (PGL) syndromes result from germline mutations in genes encoding subunits B, C and D of the mitochondrial enzyme succinate dehydrogenase (SDHB, SDHC and SDHD). SDHB-related PGLs are known in particular for their high malignant potential. Recently, however, maligna

  7. [Genetic variations in alcohol dehydrogenase, drinking habits and alcoholism

    DEFF Research Database (Denmark)

    Tolstrup, J.S.; Rasmussen, S.; Tybjaerg-Hansen, A.

    2008-01-01

    Alcohol is degraded primarily by alcohol dehydrogenase (ADH), and genetic variation that affects the rate of alcohol degradation is found in ADH1B and ADH1C. By genotyping 9,080 white men and women from the general population, we found that men and women with ADH1B slow versus fast alcohol...

  8. Purification and characterization of xylitol dehydrogenase from Fusarium oxysporum

    DEFF Research Database (Denmark)

    Panagiotou, Gianni; Kekos, D.; Macris, B.J.;

    2002-01-01

    An NAD(+)-dependent xylitol dehydrogenase (XDH) from Fusarium oxysporum, a key enzyme in the conversion of xylose to ethanol, was purified to homogeneity and characterised. It was homodimeric with a subunit of M-r 48 000, and pI 3.6. It was optimally active at 45degreesC and pH 9-10. It was fully...

  9. Medium-chain acyl-CoA dehydrogenase deficiency

    DEFF Research Database (Denmark)

    Waddell, Leigh; Wiley, Veronica; Carpenter, Kevin

    2006-01-01

    The fatty acid oxidation disorder most commonly identified by tandem mass spectrometry newborn screening is the potentially fatal medium-chain acyl-CoA dehydrogenase deficiency (MCAD). In clinically presenting cases, 80% are homozygous for the common mutation, c.985A > G and 18% heterozygous. We ...

  10. Cofactor engineering of Lactobacillus brevis alcohol dehydrogenase by computational design

    NARCIS (Netherlands)

    Machielsen, M.P.; Looger, L.L.; Raedts, J.G.J.; Dijkhuizen, S.; Hummel, W.; Henneman, H.G.; Daussmann, T.; Oost, van der J.

    2009-01-01

    The R-specific alcohol dehydrogenase from Lactobacillus brevis (Lb-ADH) catalyzes the enantioselective reduction of prochiral ketones to the corresponding secondary alcohols. It is stable and has broad substrate specificity. These features make this enzyme an attractive candidate for biotechnologica

  11. Succinate dehydrogenase is the regulator of respiration in Mycobacterium tuberculosis.

    Directory of Open Access Journals (Sweden)

    Travis Hartman

    2014-11-01

    Full Text Available In chronic infection, Mycobacterium tuberculosis bacilli are thought to enter a metabolic program that provides sufficient energy for maintenance of the protonmotive force, but is insufficient to meet the demands of cellular growth. We sought to understand this metabolic downshift genetically by targeting succinate dehydrogenase, the enzyme which couples the growth processes controlled by the TCA cycle with the energy production resulting from the electron transport chain. M. tuberculosis contains two operons which are predicted to encode succinate dehydrogenase enzymes (sdh-1 and sdh-2; we found that deletion of Sdh1 contributes to an inability to survive long term stationary phase. Stable isotope labeling and mass spectrometry revealed that Sdh1 functions as a succinate dehydrogenase during aerobic growth, and that Sdh2 is dispensable for this catalysis, but partially overlapping activities ensure that the loss of one enzyme can incompletely compensate for loss of the other. Deletion of Sdh1 disturbs the rate of respiration via the mycobacterial electron transport chain, resulting in an increased proportion of reduced electron carrier (menaquinol which leads to increased oxygen consumption. The loss of respiratory control leads to an inability to recover from stationary phase. We propose a model in which succinate dehydrogenase is a governor of cellular respiration in the adaptation to low oxygen environments.

  12. Alcohol consumption, alcohol dehydrogenase 3 polymorphism, and colorectal adenomas

    NARCIS (Netherlands)

    Tiemersma, E.W.; Wark, P.A.; Ocké, M.C.; Bunschoten, A.; Otten, M.H.; Kok, F.J.; Kampman, E.

    2003-01-01

    Alcohol is a probable risk factor with regard to colorectal neoplasm and is metabolized to the carcinogen acetaldehyde by the genetically polymorphic alcohol dehydrogenase 3 (ADH3) enzyme. We evaluated whether the association between alcohol and colorectal adenomas is modified by ADH3 polymorphism.

  13. 21 CFR 862.1440 - Lactate dehydrogenase test system.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Lactate dehydrogenase test system. 862.1440 Section 862.1440 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Chemistry...

  14. Nondecarboxylating and decarboxylating isocitrate dehydrogenases: oxalosuccinate reductase as an ancestral form of isocitrate dehydrogenase.

    Science.gov (United States)

    Aoshima, Miho; Igarashi, Yasuo

    2008-03-01

    Isocitrate dehydrogenase (ICDH) from Hydrogenobacter thermophilus catalyzes the reduction of oxalosuccinate, which corresponds to the second step of the reductive carboxylation of 2-oxoglutarate in the reductive tricarboxylic acid cycle. In this study, the oxidation reaction catalyzed by H. thermophilus ICDH was kinetically analyzed. As a result, a rapid equilibrium random-order mechanism was suggested. The affinities of both substrates (isocitrate and NAD+) toward the enzyme were extremely low compared to other known ICDHs. The binding activities of isocitrate and NAD+ were not independent; rather, the binding of one substrate considerably promoted the binding of the other. A product inhibition assay demonstrated that NADH is a potent inhibitor, although 2-oxoglutarate did not exhibit an inhibitory effect. Further chromatographic analysis demonstrated that oxalosuccinate, rather than 2-oxoglutarate, is the reaction product. Thus, it was shown that H. thermophilus ICDH is a nondecarboxylating ICDH that catalyzes the conversion between isocitrate and oxalosuccinate by oxidation and reduction. This nondecarboxylating ICDH is distinct from well-known decarboxylating ICDHs and should be categorized as a new enzyme. Oxalosuccinate-reducing enzyme may be the ancestral form of ICDH, which evolved to the extant isocitrate oxidative decarboxylating enzyme by acquiring higher substrate affinities.

  15. Acyl-CoA Dehydrogenase 9 Is Required for the Biogenesis of Oxidative Phosphorylation Complex I

    NARCIS (Netherlands)

    J. Nouws; L. Nijtmans; S.M. Houten; M. Brand; M. Huynen; H. Venselaar; S. Hoefs; J. Gloerich; J. Kronick; T. Hutchin; P. Willems; R. Rodenburg; R. Wanders; L. van den Heuvel; J. Smeitink; R.O. Vogel

    2010-01-01

    Acyl-CoA dehydrogenase 9 (ACAD9) is a recently identified member of the acyl-CoA dehydrogenase family. It closely resembles very long-chain acyl-CoA dehydrogenase (VLCAD), involved in mitochondria! (3 oxidation of long-chain fatty acids. Contrary to its previously proposed involvement in fatty acid

  16. Heme binding properties of glyceraldehyde-3-phosphate dehydrogenase.

    Science.gov (United States)

    Hannibal, Luciana; Collins, Daniel; Brassard, Julie; Chakravarti, Ritu; Vempati, Rajesh; Dorlet, Pierre; Santolini, Jérôme; Dawson, John H; Stuehr, Dennis J

    2012-10-30

    Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) is a glycolytic enzyme that also functions in transcriptional regulation, oxidative stress, vesicular trafficking, and apoptosis. Because GAPDH is required for the insertion of cellular heme into inducible nitric oxide synthase [Chakravarti, R., et al. (2010) Proc. Natl. Acad. Sci. U.S.A. 107, 18004-18009], we extensively characterized the heme binding properties of GAPDH. Substoichiometric amounts of ferric heme bound to GAPDH (one heme per GAPDH tetramer) to form a low-spin complex with UV-visible maxima at 362, 418, and 537 nm and when reduced to ferrous gave maxima at 424, 527, and 559 nm. Ferric heme association and dissociation rate constants at 10 °C were as follows: k(on) = 17800 M(-1) s(-1), k(off1) = 7.0 × 10(-3) s(-1), and k(off2) = 3.3 × 10(-4) s(-1) (giving approximate affinities of 19-390 nM). Ferrous heme bound more poorly to GAPDH and dissociated with a k(off) of 4.2 × 10(-3) s(-1). Magnetic circular dichroism, resonance Raman, and electron paramagnetic resonance spectroscopic data on the ferric, ferrous, and ferrous-CO complexes of GAPDH showed that the heme is bis-ligated with His as the proximal ligand. The distal ligand in the ferric complex was not displaced by CN(-) or N(3)(-) but in the ferrous complex could be displaced by CO at a rate of 1.75 s(-1) (for >0.2 mM CO). Studies with heme analogues revealed selectivity toward the coordinating metal and porphyrin ring structure. The GAPDH-heme complex was isolated from bacteria induced to express rabbit GAPDH in the presence of δ-aminolevulinic acid. Our finding of heme binding to GAPDH expands the protein's potential roles. The strength, selectivity, reversibility, and redox sensitivity of heme binding to GAPDH are consistent with it performing heme sensing or heme chaperone-like functions in cells.

  17. NADP-glutamate dehydrogenase isoenzymes of Saccharomyces cerevisiae. Purification, kinetic properties, and physiological roles.

    Science.gov (United States)

    DeLuna, A; Avendano, A; Riego, L; Gonzalez, A

    2001-11-23

    In the yeast Saccharomyces cerevisiae, two NADP(+)-dependent glutamate dehydrogenases (NADP-GDHs) encoded by GDH1 and GDH3 catalyze the synthesis of glutamate from ammonium and alpha-ketoglutarate. The GDH2-encoded NAD(+)-dependent glutamate dehydrogenase degrades glutamate producing ammonium and alpha-ketoglutarate. Until very recently, it was considered that only one biosynthetic NADP-GDH was present in S. cerevisiae. This fact hindered understanding the physiological role of each isoenzyme and the mechanisms involved in alpha-ketoglutarate channeling for glutamate biosynthesis. In this study, we purified and characterized the GDH1- and GDH3-encoded NADP-GDHs; they showed different allosteric properties and rates of alpha-ketoglutarate utilization. Analysis of the relative levels of these proteins revealed that the expression of GDH1 and GDH3 is differentially regulated and depends on the nature of the carbon source. Moreover, the physiological study of mutants lacking or overexpressing GDH1 or GDH3 suggested that these genes play nonredundant physiological roles. Our results indicate that the coordinated regulation of GDH1-, GDH3-, and GDH2-encoded enzymes results in glutamate biosynthesis and balanced utilization of alpha-ketoglutarate under fermentative and respiratory conditions. The possible relevance of the duplicated NADP-GDH pathway in the adaptation to facultative metabolism is discussed.

  18. Molecular cloning, purification, and biochemical characterization of recombinant isocitrate dehydrogenase from Streptomyces coelicolor M-145.

    Science.gov (United States)

    Takahashi-Iñiguez, Tóshiko; Cruz-Rabadán, Saul; Burciaga-Cifuentes, Luis Miguel; Flores, María Elena

    2014-01-01

    Isocitrate dehydrogenase is a key enzyme in carbon metabolism. In this study we demonstrated that SCO7000 of Streptomyces coelicolor M-145 codes for the isocitrate dehydrogenase. Recombinant enzyme expressed in Escherichia coli had a specific activity of 25.3 μmoles/mg/min using NADP(+) and Mn(2+) as a cofactor, 40-times higher than that obtained in cell-free extract. Pure IDH showed a single band with an apparent Mr of 84 KDa in SDS-PAGE, which was also recognized as His-tag protein in the Western blot. Unexpectedly, in ND-PAGE conditions showed a predominant band of ~168 KDa that corresponded to the dimeric form of ScIDH. Also, zymogram assay and analytical gel filtration reveal that dimer was the active form. Kinetic parameters were 1.38, 0.11, and 0.109 mM for isocitrate, NADP, and Mn(2+), respectively. ATP, ADP, AMP, and their mixtures were the main ScIDH activity inhibitors. Zn(2+), Mg(2+), Ca(2+), and Cu(+) had inhibitory effect on enzyme activity.

  19. Characterization of the immunogenicity and pathogenicity of malate dehydrogenase in Brucella abortus.

    Science.gov (United States)

    Han, Xiangan; Tong, Yongliang; Tian, Mingxing; Sun, Xiaoqing; Wang, Shaohui; Ding, Chan; Yu, Shengqing

    2014-07-01

    Brucella abortus is a gram-negative, facultative intracellular pathogen that causes brucellosis, a chronic zoonotic disease resulting in abortion in pregnant cattle and undulant fever in humans. Malate dehydrogenase (MDH), a key enzyme in the tricarboxylic acid cycle, plays important metabolic roles in aerobic energy producing pathways and in malate shuttle. In this study, the MDH-encoding gene for malate dehydrogenase mdh of B. abortus S2308 was cloned, sequenced and expressed. Western blot analysis demonstrated that MDH is an immunogenic membrane-associated protein. In addition, recombinant MDH showed sero-reactivity with 30 individual bovine B. abortus-positive sera by enzyme-linked immunosorbent assay, indicates that MDH may be used as a candidate marker for sero-diagnosis of brucellosis. Furthermore, MDH exhibits fibronectin and plasminogen-binding ability in immunoblotting assay. Inhibition assays on HeLa cells demonstrated that rabbit anti-serum against MDH significantly reduced both bacterial adherence and invasion abilities (p < 0.05), suggesting that MDH play a role in B. abortus colonization. Our results indicated that MDH is not only an immunogenic protein, but is also related to bacterial pathogenesis and may act as a new virulent factor, which will benefit for further understanding the MDH's roles in B. abortus metabolism, pathogenesis and immunity.

  20. Analysis of lactate and malate dehydrogenase enzyme profiles of selected major carps of wetland of Calcutta.

    Science.gov (United States)

    Manna, Madhumita; Chakraborty, Priyanka

    2012-07-01

    The East Calcutta Wetland (ECW), a Ramsar site in India, acts as the only sink for both city sewages as well as effluents from the surrounding small-scale industries and is alarmingly polluted with heavy metals. The three best edible major carp species rohu (Labeo rohita,), catla (Catla catla,) and mrigala (Cirrhinus mrigala) were undertaken to monitor lactate dehydrogenase (LDH) and malate dehydrogenase (MDH) by cellulose acetate electrophoresis (CAE) to assess the effects of pollutants, if any. Crude tissue extracts were prepared from brain, eye, heart, skeletal muscle and kidney tissue respectively from each type of fish. No differences were not found in MDH of catla from both sites for all tissues analyzed in this study. Rohu also showed similar mobility for all tissues except for heart tissue which was distinctly different in fishes from ECW site than that of its counterpart from non ECW site. On the other hand, MDH of two tissues of mrigala, eye and muscle respectively showed different migration patterns. LDH profiles for all tissues of three fish species from both the sites were consistently similar, only the expression levels of muscle LDH of mrigala and kidney LDH of rohu varied little.

  1. Multiple independent fusions of glucose-6-phosphate dehydrogenase with enzymes in the pentose phosphate pathway.

    Directory of Open Access Journals (Sweden)

    Nicholas A Stover

    Full Text Available Fusions of the first two enzymes in the pentose phosphate pathway, glucose-6-phosphate dehydrogenase (G6PD and 6-phosphogluconolactonase (6PGL, have been previously described in two distant clades, chordates and species of the malarial parasite Plasmodium. We have analyzed genome and expressed sequence data from a variety of organisms to identify the origins of these gene fusion events. Based on the orientation of the domains and range of species in which homologs can be found, the fusions appear to have occurred independently, near the base of the metazoan and apicomplexan lineages. Only one of the two metazoan paralogs of G6PD is fused, showing that the fusion occurred after a duplication event, which we have traced back to an ancestor of choanoflagellates and metazoans. The Plasmodium genes are known to contain a functionally important insertion that is not seen in the other apicomplexan fusions, highlighting this as a unique characteristic of this group. Surprisingly, our search revealed two additional fusion events, one that combined 6PGL and G6PD in an ancestor of the protozoan parasites Trichomonas and Giardia, and another fusing G6PD with phosphogluconate dehydrogenase (6PGD in a species of diatoms. This study extends the range of species known to contain fusions in the pentose phosphate pathway to many new medically and economically important organisms.

  2. Refolding of a thermostable glyceraldehyde dehydrogenase for application in synthetic cascade biomanufacturing.

    Directory of Open Access Journals (Sweden)

    Fabian Steffler

    Full Text Available The production of chemicals from renewable resources is gaining importance in the light of limited fossil resources. One promising alternative to widespread fermentation based methods used here is Synthetic Cascade Biomanufacturing, the application of minimized biocatalytic reaction cascades in cell free processes. One recent example is the development of the phosphorylation independent conversion of glucose to ethanol and isobutanol using only 6 and 8 enzymes, respectively. A key enzyme for this pathway is aldehyde dehydrogenase from Thermoplasma acidophilum, which catalyzes the highly substrate specific oxidation of d-glyceraldehyde to d-glycerate. In this work the enzyme was recombinantly expressed in Escherichia coli. Using matrix-assisted refolding of inclusion bodies the yield of enzyme production was enhanced 43-fold and thus for the first time the enzyme was provided in substantial amounts. Characterization of structural stability verified correct refolding of the protein. The stability of the enzyme was determined by guanidinium chloride as well as isobutanol induced denaturation to be ca. -8 kJ/mol both at 25°C and 40°C. The aldehyde dehydrogenase is active at high temperatures and in the presence of small amounts of organic solvents. In contrast to previous publications, the enzyme was found to accept NAD(+ as cofactor making it suitable for application in the artificial glycolysis.

  3. P450BM3 fused to phosphite dehydrogenase allows phosphite-driven selective oxidations.

    Science.gov (United States)

    Beyer, Nina; Kulig, Justyna K; Bartsch, Anette; Hayes, Martin A; Janssen, Dick B; Fraaije, Marco W

    2017-03-01

    To facilitate the wider application of the NADPH-dependent P450BM3, we fused the monooxygenase with a phosphite dehydrogenase (PTDH). The resulting monooxygenase-dehydrogenase fusion enzyme acts as a self-sufficient bifunctional catalyst, accepting phosphite as a cheap electron donor for the regeneration of NADPH.The well-expressed fusion enzyme was purified and analyzed in comparison to the parent enzymes. Using lauric acid as substrate for P450BM3, it was found that the fusion enzyme had similar substrate affinity and hydroxylation selectivity while it displayed a significantly higher activity than the non-fused monooxygenase. Phosphite-driven conversions of lauric acid at restricted NADPH concentrations confirmed multiple turnovers of the cofactor. Interestingly, both the fusion enzyme and the native P450BM3 displayed enzyme concentration dependent activity and the fused enzyme reached optimal activity at a lower enzyme concentration. This suggests that the fusion enzyme has an improved tendency to form functional oligomers.To explore the constructed phosphite-driven P450BM3 as a biocatalyst, conversions of the drug compounds omeprazole and rosiglitazone were performed. PTDH-P450BM3 driven by phosphite was found to be more efficient in terms of total turnover when compared with P450BM3 driven by NADPH. The results suggest that PTDH-P450BM3 is an attractive system for use in biocatalytic and drug metabolism studies.

  4. Effects of membrane-bound glucose dehydrogenase overproduction on the respiratory chain of Gluconobacter oxydans.

    Science.gov (United States)

    Meyer, Maria; Schweiger, Paul; Deppenmeier, Uwe

    2013-04-01

    The acetic acid bacterium Gluconobacter oxydans incompletely oxidizes carbon sources as a natural part of its metabolism, and this feature has been exploited for many biotechnological applications. The most important enzymes used to harness the biocatalytic oxidative capacity of G. oxydans are the pyrroloquinoline quinone (PQQ)-dependent dehydrogenases. The membrane-bound PQQ-dependent glucose dehydrogenase (mGDH), encoded by gox0265, was used as model protein for homologous membrane protein production using the previously described Gluconobacter expression vector pBBR1p452. The mgdh gene had ninefold higher expression in the overproduction strain compared to the parental strain. Furthermore, membranes from the overexpression strain had a five- and threefold increase of mGDH activity and oxygen consumption rates, respectively. Oxygen consumption rate of the membrane fraction could not be increased by the addition of a substrate combination of glucose and ethanol in the overproduction strain, indicating that the terminal quinol oxidases of the respiratory chain were rate limiting. In contrast, addition of glucose and ethanol to membranes of the control strain increased oxygen consumption rates approaching the observed rates with G. oxydans overproducing mGDH. The higher glucose oxidation rates of the mGDH overproduction strain corresponded to a 70 % increase of the gluconate production rate compared to the control strain. The high rate of glucose oxidation may be useful in the industrial production of gluconates and ketogluconates, or as whole-cell biosensors. Furthermore, mGDH was purified to homogeneity by one-step strep-tactin affinity chromatography and characterized. To our knowledge, this is the first report of a membrane integral quinoprotein being purified by affinity chromatography and serves as a proof-of-principle for using G. oxydans as a host for membrane protein expression and purification.

  5. Effect of glucocorticoid on promoter of 11β-hydroxysteroid dehydrogenase I gene

    Institute of Scientific and Technical Information of China (English)

    何平; 孙刚

    2003-01-01

    Objective: To study the effect of glucocorticoid on the promoter of the pre-receptor glucocorticoid metabolizing enzyme 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) gene. Methods: The 1.2 kb length sequence upstream to the transcription start site of the 11β-HSD1 gene was amplified with polymerase chain reaction (PCR) and then was cloned into pBLCAT6 plasmid carrying chloramphenicol acetyltransferase (CAT) reporter gene. The plasmid pBLCAT6 carrying the promoter and reporter gene was used to transfect HeLa cells to study the regulation of 11β-HSD1 gene expression by glucocorticoids in terms of reporter gene expression. Results: PCR showed that there was a complete alignment of the amplified sequence with the sequence 1.2 kb upstream to the transcription start site of 11β-HSD1 gene. When cloned into pBLCAT6 plasmid carrying the reporter gene, this part of the promoter is functional in terms of regulation of reporter gene expression upon transfection into HeLa cells. The synthetic glucocorticoid-dexamethasone induced the reporter gene expression in the system described above, which was blocked by glucocorticoid receptor antagonist RU486. Conclusion: Glucocorticoids can modulate the expression of 11β-HSD1 through a mechanism involving activation of GR and interaction of the promoter of 11β-HSD1 gene.

  6. 殊异韦荣菌苹果酸脱氢酶的基因克隆及其重组蛋白的表达和活性测定%Cloning, the Recombinant Protein Expressing and the Activity of Malate Dehydrogenase Gene of Veillonella Dispar

    Institute of Scientific and Technical Information of China (English)

    刘晓红; 何钟勤; 孙晓宇; 高心; 薛莹; 李倪娜

    2013-01-01

    目的:对殊异韦荣菌(V·dispar)苹果酸脱氢酶(malate dehydrogenase,MDH)基因进行克隆和重组表达,并对其重组蛋白进行纯化和活性测定.方法:提取殊异韦荣菌基因组DNA,PCR扩增MDH同源区序列片段,克隆入pET-28a载体并转化至大肠杆菌DH5α,酶切及PCR鉴定,测序.将重组质粒转入BL21 (DE3)中,选择最佳表达条件,提纯及测定活性.结果:PCR扩增产物特异,全长1139 bp.测序结果包含MDH基因,并与GenBank中所报道的大肠杆菌MDH基因序列进行对比分析,其同源性为99%.MDH纯化后的蛋白活性值为0.4403 U/mL.结论:成功克隆殊异韦荣菌MDH基因,并通过基因序列和氨基酸分析证明其具有完整的阅读框架.还获得了重组表达MDH蛋白的最适表达条件,并测出韦荣菌苹果酸脱氢酶的活性.

  7. 亚洲牛带绦虫36kDa胞浆型苹果酸脱氢酶基因的表达、纯化及免疫学分析%The expression and purification of the 36 kDa cytoplasmic malate dehydrogenase gene in Taenia saginata asiatica and the immunologic analysis of the recombinant proteins

    Institute of Scientific and Technical Information of China (English)

    黄江; 胡旭初; 徐劲; 余新炳; 包怀恩; 郎书源; 廖兴江

    2008-01-01

    目的 对亚洲牛带绦虫胞浆型苹果酸脱氢酶基因(malate dehydrogenase,MDH)进行克隆、表达和免疫学研究.方法 将亚洲牛带绦虫成虫MDH克隆到原核表达质粒pET-30a(+)中.在大肠埃希菌BL-21/DE3中用IPTG诱导表达,表达产物通过十二烷基磺酸钠-聚丙烯酰胺凝胶电泳(SDS-PAGE)进行鉴定.用镍离子金属螯合剂亲和层析柱进行纯化,纯化的重组蛋白用蛋白印迹(Western Blotting)进行免疫学分析.结果 PCR、双酶切及DNA测序结果均表明pET-30a(+)-TaMDH重组质粒构建成功.SDS-PAGE结果表明目的基因在大肠埃希菌BL-21/DE3中获得高效表达,经亲和层析获得了商纯度蛋白.重组蛋白可被其免疫的SD大鼠血清识别,表明其具有免疫原性;并且能识别感染了亚洲牛带绦虫的猪血清.表明其具有免疫反应性.结论 亚洲牛带绦虫苹果酸脱氢酶基因可在原核表达系统中获得具有免疫学活性的高效表达,为进一步研究该蛋白的功能奠定了基础.

  8. Cloning of the Arabidopsis and Rice Formaldehyde Dehydrogenase Genes: Implications for the Origin of Plant Adh Enzymes

    Science.gov (United States)

    Dolferus, R.; Osterman, J. C.; Peacock, W. J.; Dennis, E. S.

    1997-01-01

    This article reports the cloning of the genes encoding the Arabidopsis and rice class III ADH enzymes, members of the alcohol dehydrogenase or medium chain reductase/dehydrogenase superfamily of proteins with glutathione-dependent formaldehyde dehydrogenase activity (GSH-FDH). Both genes contain eight introns in exactly the same positions, and these positions are conserved in plant ethanol-active Adh genes (class P). These data provide further evidence that plant class P genes have evolved from class III genes by gene duplication and acquisition of new substrate specificities. The position of introns and similarities in the nucleic acid and amino acid sequences of the different classes of ADH enzymes in plants and humans suggest that plant and animal class III enzymes diverged before they duplicated to give rise to plant and animal ethanol-active ADH enzymes. Plant class P ADH enzymes have gained substrate specificities and evolved promoters with different expression properties, in keeping with their metabolic function as part of the alcohol fermentation pathway. PMID:9215914

  9. Investigation of XoxF methanol dehydrogenases reveals new methylotrophic bacteria in pelagic marine and freshwater ecosystems.

    Science.gov (United States)

    Ramachandran, Arthi; Walsh, David A

    2015-10-01

    The diversity and distribution of methylotrophic bacteria have been investigated in the oceans and lakes using the methanol dehydrogenase mxaF gene as a functional marker. However, pelagic marine (OM43) and freshwater (LD28 and PRD01a001B) methylotrophs within the Betaproteobacteria lack mxaF, instead possessing a related xoxF4-encoded methanol dehydrogenase. Here, we developed and employed xoxF4 as a complementary functional gene marker to mxaF for studying methylotrophs in aquatic environment. Using xoxF4, we detected OM43-related and LD28-related methylotrophs in the ocean and freshwaters of North America, respectively, and showed the coexistence of these two lineages in a large estuarine system (St Lawrence Estuary). Gene expression patterns of xoxF4 supported a positive relationship between xoxF4-containing methylotroph activity and spring time productivity, suggesting phytoplankton blooms are a source of methylotrophic substrates. Further investigation of methanol dehydrogenase diversity in pelagic ecosystems using comparative metagenomics provided strong support for a widespread distribution of xoxF4 (as well as several distinct xoxF5) containing methylotrophs in marine and freshwater surface waters. In total, these results demonstrate a geographical distribution of OM43/LD28-related methylotrophs that includes marine and freshwaters and suggest that methylotrophy occurring in the water column is an important component of lake and estuary carbon cycling and biogeochemistry.

  10. Fungal laccase, cellobiose dehydrogenase, and chemical mediators: combined actions for the decolorization of different classes of textile dyes.

    Science.gov (United States)

    Ciullini, Ilaria; Tilli, Silvia; Scozzafava, Andrea; Briganti, Fabrizio

    2008-10-01

    Dyes belonging to the mono-, di-, tri- and poly-azo as well as anthraquinonic and mono-azo Cr-complexed classes, chosen among the most utilized in textile applications, were employed for a comparative enzymatic decolorization study using the extracellular crude culture extracts from the white rot fungus Funalia (Trametes) trogii grown on different culture media and activators able to trigger different levels of expression of oxidizing enzymes: laccase and cellobiose dehydrogenase. Laccase containing extracts were capable to decolorize some dyes from all the different classes analyzed, whereas the recalcitrant dyes were subjected to the combined action of laccase and the chemical mediator HBT, or laccase plus cellobiose dehydrogenase. Correlations among the decolorization degree of the various dyes and their electronic and structural diversities were rationalized and discussed. The utilization of cellobiose dehydrogenase in support to the activity of laccase for the decolorization of azo textile dyes resulted in substantial increases in decolorization for all the refractory dyes proving to be a valid alternative to more expensive and less environmentally friendly chemical treatments of textile dyes wastes.

  11. A comparison of two novel alcohol dehydrogenase enzymes (ADH1 and ADH2) from the extreme halophile Haloferax volcanii.

    Science.gov (United States)

    Timpson, Leanne M; Liliensiek, Ann-Kathrin; Alsafadi, Diya; Cassidy, Jennifer; Sharkey, Michael A; Liddell, Susan; Allers, Thorsten; Paradisi, Francesca

    2013-01-01

    Haloarchaeal alcohol dehydrogenases are exciting biocatalysts with potential industrial applications. In this study, two alcohol dehydrogenase enzymes from the extremely halophilic archaeon Haloferax volcanii (HvADH1 and HvADH2) were homologously expressed and subsequently purified by immobilized metal-affinity chromatography. The proteins appeared to copurify with endogenous alcohol dehydrogenases, and a double Δadh2 Δadh1 gene deletion strain was constructed to prevent this occurrence. Purified HvADH1 and HvADH2 were compared in terms of stability and enzymatic activity over a range of pH values, salt concentrations, and temperatures. Both enzymes were haloalkaliphilic and thermoactive for the oxidative reaction and catalyzed the reductive reaction at a slightly acidic pH. While the NAD(+)-dependent HvADH1 showed a preference for short-chain alcohols and was inherently unstable, HvADH2 exhibited dual cofactor specificity, accepted a broad range of substrates, and, with respect to HvADH1, was remarkably stable. Furthermore, HvADH2 exhibited tolerance to organic solvents. HvADH2 therefore displays much greater potential as an industrially useful biocatalyst than HvADH1.

  12. An Fe-S cluster in the conserved Cys-rich region in the catalytic subunit of FAD-dependent dehydrogenase complexes.

    Science.gov (United States)

    Shiota, Masaki; Yamazaki, Tomohiko; Yoshimatsu, Keiichi; Kojima, Katsuhiro; Tsugawa, Wakako; Ferri, Stefano; Sode, Koji

    2016-12-01

    Several bacterial flavin adenine dinucleotide (FAD)-harboring dehydrogenase complexes comprise three distinct subunits: a catalytic subunit with FAD, a cytochrome c subunit containing three hemes, and a small subunit. Owing to the cytochrome c subunit, these dehydrogenase complexes have the potential to transfer electrons directly to an electrode. Despite various electrochemical applications and engineering studies of FAD-dependent dehydrogenase complexes, the intra/inter-molecular electron transfer pathway has not yet been revealed. In this study, we focused on the conserved Cys-rich region in the catalytic subunits using the catalytic subunit of FAD dependent glucose dehydrogenase complex (FADGDH) as a model, and site-directed mutagenesis and electron paramagnetic resonance (EPR) were performed. By co-expressing a hitch-hiker protein (γ-subunit) and a catalytic subunit (α-subunit), FADGDH γα complexes were prepared, and the properties of the catalytic subunit of both wild type and mutant FADGDHs were investigated. Substitution of the conserved Cys residues with Ser resulted in the loss of dye-mediated glucose dehydrogenase activity. ICP-AEM and EPR analyses of the wild-type FADGDH catalytic subunit revealed the presence of a 3Fe-4S-type iron-sulfur cluster, whereas none of the Ser-substituted mutants showed the EPR spectrum characteristic for this cluster. The results suggested that three Cys residues in the Cys-rich region constitute an iron-sulfur cluster that may play an important role in the electron transfer from FAD (intra-molecular) to the multi-heme cytochrome c subunit (inter-molecular) electron transfer pathway. These features appear to be conserved in the other three-subunit dehydrogenases having an FAD cofactor.

  13. Molecular Pathways: Isocitrate Dehydrogenase Mutations in Cancer.

    Science.gov (United States)

    Clark, Owen; Yen, Katharine; Mellinghoff, Ingo K

    2016-04-15

    IDH1 and IDH2 are homodimeric enzymes that catalyze the conversion of isocitrate to α-ketoglutarate (α-KG) and concomitantly produce reduced NADPH from NADP(+) Mutations in the genes encoding IDH1 and IDH2 have recently been found in a variety of human cancers, most commonly glioma, acute myeloid leukemia (AML), chondrosarcoma, and intrahepatic cholangiocarcinoma. The mutant protein loses its normal enzymatic activity and gains a new ability to produce the "oncometabolite" R(-)-2-hydroxyglutarate (R-2-HG). R-2-HG competitively inhibits α-KG-dependent enzymes which play crucial roles in gene regulation and tissue homeostasis. Expression of mutant IDH impairs cellular differentiation in various cell lineages and promotes tumor development in cooperation with other cancer genes. First-generation inhibitors of mutant IDH have entered clinical trials, and have shown encouraging results in patients with IDH-mutant AML. This article summarizes recent progress in our understanding of the role of mutant IDH in tumorigenesis.Clin Cancer Res; 22(8); 1837-42. ©2016 AACR.

  14. Characterization of Arabidopsis lines deficient in GAPC-1, a cytosolic NAD-dependent glyceraldehyde-3-phosphate dehydrogenase.

    Science.gov (United States)

    Rius, Sebastián P; Casati, Paula; Iglesias, Alberto A; Gomez-Casati, Diego F

    2008-11-01

    Phosphorylating glyceraldehyde-3-P dehydrogenase (GAPC-1) is a highly conserved cytosolic enzyme that catalyzes the conversion of glyceraldehyde-3-P to 1,3-bis-phosphoglycerate; besides its participation in glycolysis, it is thought to be involved in additional cellular functions. To reach an integrative view on the many roles played by this enzyme, we characterized a homozygous gapc-1 null mutant and an as-GAPC1 line of Arabidopsis (Arabidopsis thaliana). Both mutant plant lines show a delay in growth, morphological alterations in siliques, and low seed number. Embryo development was altered, showing abortions and empty embryonic sacs in basal and apical siliques, respectively. The gapc-1 line shows a decrease in ATP levels and reduced respiratory rate. Furthermore, both lines exhibit a decrease in the expression and activity of aconitase and succinate dehydrogenase and reduced levels of pyruvate and several Krebs cycle intermediates, as well as increased reactive oxygen species levels. Transcriptome analysis of the gapc-1 mutants unveils a differential accumulation of transcripts encoding for enzymes involved in carbon partitioning. According to these studies, some enzymes involved in carbon flux decreased (phosphoenolpyruvate carboxylase, NAD-malic enzyme, glucose-6-P dehydrogenase) or increased (NAD-malate dehydrogenase) their activities compared to the wild-type line. Taken together, our data indicate that a deficiency in the cytosolic GAPC activity results in modifications of carbon flux and mitochondrial dysfunction, leading to an alteration of plant and embryo development with decreased number of seeds, indicating that GAPC-1 is essential for normal fertility in Arabidopsis plants.

  15. Investigation of the Amycolatopsis sp. strain ATCC 39116 vanillin dehydrogenase and its impact on the biotechnical production of vanillin.

    Science.gov (United States)

    Fleige, Christian; Hansen, Gunda; Kroll, Jens; Steinbüchel, Alexander

    2013-01-01

    The actinomycete Amycolatopsis sp. strain ATCC 39116 is capable of synthesizing large amounts of vanillin from ferulic acid, which is a natural cell wall component of higher plants. The desired intermediate vanillin is subject to undesired catabolism caused by the metabolic activity of a hitherto unknown vanillin dehydrogenase (VDH(ATCC 39116)). In order to prevent the oxidation of vanillin to vanillic acid and thereby to obtain higher yields and concentrations of vanillin, the responsible vanillin dehydrogenase in Amycolatopsis sp. ATCC 39116 was investigated for the first time by using data from our genome sequence analysis and further bioinformatic approaches. The vdh gene was heterologously expressed in Escherichia coli, and the encoded vanillin dehydrogenase was characterized in detail. VDH(ATCC 39116) was purified to apparent electrophoretic homogeneity and exhibited NAD(+)-dependent activity toward vanillin, coniferylaldehyde, cinnamaldehyde, and benzaldehyde. The enzyme showed its highest level of activity toward vanillin at pH 8.0 and at a temperature of 44°C. In a next step, a precise vdh deletion mutant of Amycolatopsis sp. ATCC 39116 was generated. The mutant lost its ability to grow on vanillin and did not show vanillin dehydrogenase activity. A 2.3-times-higher vanillin concentration and a substantially reduced amount of vanillic acid occurred with the Amycolatopsis sp. ATCC 39116 Δvdh::Km(r) mutant when ferulic acid was provided for biotransformation in a cultivation experiment on a 2-liter-bioreactor scale. Based on these results and taking further metabolic engineering into account, the Amycolatopsis sp. ATCC 39116 Δvdh::Km(r) mutant represents an optimized and industrially applicable platform for the biotechnological production of natural vanillin.

  16. Glucose replaces glutamate as energy substrate to fuel glutamate uptake in glutamate dehydrogenase-deficient astrocytes

    DEFF Research Database (Denmark)

    Pajęcka, Kamilla; Nissen, Jakob D; Stridh, Malin H;

    2015-01-01

    Cultured astrocytes treated with siRNA to knock down glutamate dehydrogenase (GDH) were used to investigate whether this enzyme is important for the utilization of glutamate as an energy substrate. By incubation of these cells in media containing different concentrations of glutamate (range 100......-500 µM) in the presence or in the absence of glucose, the metabolism of these substrates was studied by using tritiated glutamate or 2-deoxyglucose as tracers. In addition, the cellular contents of glutamate and ATP were determined. The astrocytes were able to maintain physiological levels of ATP...... regardless of the expression level of GDH and the incubation condition, indicating a high degree of flexibility with regard to regulatory mechanisms involved in maintaining an adequate energy level in the cells. Glutamate uptake was found to be increased in these cells when exposed to increasing levels...

  17. Novel inhibitors of 17beta-hydroxysteroid dehydrogenase type 1: templates for design.

    Science.gov (United States)

    Allan, Gillian M; Vicker, Nigel; Lawrence, Harshani R; Tutill, Helena J; Day, Joanna M; Huchet, Marion; Ferrandis, Eric; Reed, Michael J; Purohit, Atul; Potter, Barry V L

    2008-04-15

    The 17beta-hydroxysteroid dehydrogenases (17beta-HSDs) catalyze the interconversion between the oxidized and reduced forms of androgens and estrogens at the 17 position. The 17beta-HSD type 1 enzyme (17beta-HSD1) catalyzes the reduction of estrone (E1) to estradiol and is expressed in malignant breast cells. Inhibitors of this enzyme thus have potential as treatments for hormone dependent breast cancer. Syntheses and biological evaluation of novel non-steroidal inhibitors designed to mimic the E1 template are reported using information from potent steroidal inhibitors. Of the templates investigated biphenyl ethanone was promising and led to inhibitors with IC(50) values in the low micromolar range.

  18. Functional characterization of NADP-dependent isocitrate dehydrogenase isozymes from Trypanosoma cruzi.

    Science.gov (United States)

    Leroux, Alejandro E; Maugeri, Dante A; Cazzulo, Juan J; Nowicki, Cristina

    2011-05-01

    Trypanosoma cruzi exhibits two putative isocitrate dehydrogenases (IDHs). Both idh genes were cloned and the recombinant enzymes expressed in Escherichia coli. Our results showed that T. cruzi IDHs are strictly dependent on NADP(+) and display apparent affinities towards isocitrate and the coenzyme in the low micromolar range. In T. cruzi, IDHs are cytosolic and mitochondrial enzymes, and there is no evidence for the typical Krebs cycle-related NAD-dependent IDH. Hence, like in Trypanosoma brucei, the Krebs cycle is not a canonical route in T. cruzi. However, the citrate produced in the mitochondrion could be isomerized into isocitrate in the cytosol and the mitochondrion by means of the putative aconitase, which would provide the substrate for both IDHs. The cytosolic IDH is significantly more abundant in amastigotes, cell-derived and metacyclic trypomastigotes than in epimastigotes. This observation fits in well with the expected oxidative burst this pathogen has to face when infecting the mammalian host.

  19. Phosphorylation controls the functioning of Staphylococcus aureus isocitrate dehydrogenase--favours biofilm formation.

    Science.gov (United States)

    Prasad, U Venkateswara; Vasu, D; Yeswanth, S; Swarupa, V; Sunitha, M M; Choudhary, A; Sarma, P V G K

    2015-01-01

    Isocitrate dehydrogenase (IDH) gene from Staphylococcus aureus ATCC12600 was cloned, sequenced and characterized (HM067707). PknB site was observed in the active site of IDH; thus, it was predicted as IDH may be regulated by phosphorylation. Therefore, in this study, PknB, alkaline phosphatase III (SAOV 2675) and IDH genes (JN695616, JN645811 and HM067707) of S. aureus ATCC12600 were over expressed from clones PV 1, UVPALP-3 and UVIDH 1. On passing the cytosloic fractions through nickel metal chelate column, pure enzymes were obtained. Phosphorylation of pure IDH by PknB resulted in the complete loss of activity and was restored upon dephosphorylation with SAOV 2675 which indicated that phosphorylation and dephosphorylation regulate IDH activity in S. aureus. Further, when S. aureus ATCC12600 was grown in BHI broth, decreased IDH activity and increased biofilm units were observed; therefore, this regulation of IDH alters redox status in this pathogen favouring biofilm formation.

  20. Effect of radiation in utero on mouse testes lactate dehydrogenase-X

    Energy Technology Data Exchange (ETDEWEB)

    Prasad, N.; Prasad, R.; Bushong, S.C.

    1976-01-01

    Lactate dehydrogenase-X(LDH-X), a sperm specific isozyme of mammals, can be used as a marker for active spermatogenesis. LDH-X electrophoretic patterns may also be affected in radiation-induced sterility following in utero irradiation. To investigate this relationship pregnant female mice were given 100 rad x radiation on day 10, 13, and 17 following gestation. All male offspring were sacrificed 20 days after birth and testes tissues obtained. The testes were homogenized to obtain crude extracts for starch gel electrophoresis and zymogram staining for LDH-X. Results to date show that the LDH-X is not expressed in the testis when fetal irradiation occurred at 10 and 13 days following gestation. Faint bands of LDH-X were observed in testes homogenates of mice whose mothers were irradiated 17 days following gestation. Pronounced LDH-X bands were present in all control preparations.

  1. Role of lactate dehydrogenase in metmyoglobin reduction and color stability of different bovine muscles.

    Science.gov (United States)

    Kim, Y H; Keeton, J T; Smith, S B; Berghman, L R; Savell, J W

    2009-11-01

    The role of lactate dehydrogenase (LDH) in metmyoglobin reducing activity (MRA) and color stability of different bovine muscles was studied in two consecutive experiments. In experiment 1, three different bovine muscles -M. longissimus lumborum (LL), M. semimembranosus (SM), and M. psoas major (PM) - were obtained (n=7, respectively), cut into steaks, PVC packaged, and then displayed for 7days at 1°C. The LL was the most red over display time and had more (PLDH-B activity (catalyzing toward NADH generation), LDH1 isoform expression, NADH, and higher (PLDH-B activity, NADH, and a* values after 10days display at 1°C. These results suggest that variation in color stability of physiologically different muscles is regulated by different replenishment rates of NADH via different LDH isozymes.

  2. SERUM LACTATE DEHYDROGENASE AS A PROGNOSTIC MARKER IN BREAST CANCER

    Directory of Open Access Journals (Sweden)

    Hardik

    2015-11-01

    Full Text Available : BACKGROUND: Breast cancer a multifactorial disease and one of the most dreaded of human diseases that claims the lives of thousands of women all over the globe every year. This may probably due to the fact that it remains undiagnosed at an early stage perhaps due to lack of awareness amongst the females and the fact that most cancers do not produce any symptoms until the tumour are too large to be removed surgically. Hence there is need to detect cancer at an early stage. AIM: Estimation of diagnostic importance and prognostication of serum Lactate dehydrogenase in cases on breast cancer. SETTINGS AND DESIGN: An observational study was conducted in Acharya Vinoba Bhave Rural Hospital, Sawangi (Meghe, Wardha which included 44 confirmed cases of carcinoma breast and 44 normal healthy females admitted in AVBRH in a span of 2 years. METHODS AND MATERIAL: Determination of serum LDH was done using TC matrix analyser. The values of LDH were obtained on presentation, 21 days after intervention, 2 months after intervention and 6 months after intervention. The values of LDH on presentation in both the groups were compared. The decline in the values of LDH were observed with the due course of treatment. Chisquare test and Student’s Unpaired and paired t test were used for statistical analysis. RESULT: The mean Lactate dehydrogenase on presentation was in study group and control group was 564.38±219.41 IU/L and 404.18±101.32 IU/L respectively (p<0.05. The levels of Lactate dehydrogenase decreased with due course of treatment. The levels of LDH were proportionate to the stage of disease. CONCLUSION: The results of the study concludes cost effective usefulness of serum Lactate dehydrogenase in early detection of breast cancer and to assess its prognostic importance which can be done in smaller laboratories. The traditional model of DS-

  3. GLUTAMATE DEHYDROGENASE 1 AND SIRT4 REGULATE GLIAL DEVELOPMENT

    OpenAIRE

    Komlos, Daniel; Mann, Kara D.; Zhuo, Yue; Ricupero, Christopher L.; Hart, Ronald P.; Liu, Alice Y.-C.; Firestein, Bonnie L.

    2012-01-01

    Congenital hyperinsulinism/hyperammonemia (HI/HA) syndrome is caused by an activation mutation of glutamate dehydrogenase 1 (GDH1), a mitochondrial enzyme responsible for the reversible interconversion between glutamate and α-ketoglutarate. The syndrome presents clinically with hyperammonemia, significant episodic hypoglycemia, seizures, and a frequent incidences of developmental and learning defects. Clinical research has implicated that although some of the developmental and neurological de...

  4. Optic neuropathy in a patient with pyruvate dehydrogenase deficiency

    Energy Technology Data Exchange (ETDEWEB)

    Small, Juan E. [Massachusetts General Hospital and Harvard Medical School, Department of Radiology, Boston, MA (United States); Gonzalez, Guido E. [Massachusetts Eye and Ear Infirmary and Harvard Medical School, Department of Radiology, Boston, MA (United States); Clinica Alemana de Santiago, Departmento de Imagenes, Santiago (Chile); Nagao, Karina E.; Walton, David S. [Massachusetts Eye and Ear Infirmary and Harvard Medical School, Department of Ophthalmology, Boston, MA (United States); Caruso, Paul A. [Massachusetts Eye and Ear Infirmary and Harvard Medical School, Department of Radiology, Boston, MA (United States)

    2009-10-15

    Pyruvate dehydrogenase (PDH) deficiency is a genetic disorder of mitochondrial metabolism. The clinical manifestations range from severe neonatal lactic acidosis to chronic neurodegeneration. Optic neuropathy is an uncommon clinical sequela and the imaging findings of optic neuropathy in these patients have not previously been described. We present a patient with PDH deficiency with bilateral decreased vision in whom MRI demonstrated bilateral optic neuropathy and chiasmopathy. (orig.)

  5. Encapsulation of Alcohol Dehydrogenase in Mannitol by Spray Drying

    OpenAIRE

    Hirokazu Shiga; Hiromi Joreau; Tze Loon Neoh; Takeshi Furuta; Hidefumi Yoshii

    2014-01-01

    The retention of the enzyme activity of alcohol dehydrogenase (ADH) has been studied in various drying processes such as spray drying. The aim of this study is to encapsulate ADH in mannitol, either with or without additive in order to limit the thermal denaturation of the enzyme during the drying process. The retention of ADH activity was investigated at different drying temperatures. When mannitol was used, the encapsulated ADH was found inactive in all the dried powders. This is presumably...

  6. Plasma Lactate Dehydrogenase Levels Predict Mortality in Acute Aortic Syndromes

    OpenAIRE

    Morello, Fulvio; Ravetti, Anna; Nazerian, Peiman; Liedl, Giovanni; Veglio, Maria Grazia; Battista, Stefania; Vanni, Simone; Pivetta, Emanuele; Montrucchio, Giuseppe; Mengozzi, Giulio; Rinaldi, Mauro; Moiraghi, Corrado; Lupia, Enrico

    2016-01-01

    Abstract In acute aortic syndromes (AAS), organ malperfusion represents a key event impacting both on diagnosis and outcome. Increased levels of plasma lactate dehydrogenase (LDH), a biomarker of malperfusion, have been reported in AAS, but the performance of LDH for the diagnosis of AAS and the relation of LDH with outcome in AAS have not been evaluated so far. This was a bi-centric prospective diagnostic accuracy study and a cohort outcome study. From 2008 to 2014, patients from 2 Emergency...

  7. R-lipoic acid inhibits mammalian pyruvate dehydrogenase kinase.

    Science.gov (United States)

    Korotchkina, Lioubov G; Sidhu, Sukhdeep; Patel, Mulchand S

    2004-10-01

    The four pyruvate dehydrogenase kinase (PDK) and two pyruvate dehydrogenase phosphatase (PDP) isoenzymes that are present in mammalian tissues regulate activity of the pyruvate dehydrogenase complex (PDC) by phosphorylation/dephosphorylation of its pyruvate dehydrogenase (E1) component. The effect of lipoic acids on the activity of PDKs and PDPs was investigated in purified proteins system. R-lipoic acid, S-lipoic acid and R-dihydrolipoic acid did not significantly affect activities of PDPs and at the same time inhibited PDKs to different extents (PDK1>PDK4 approximately PDK2>PDK3 for R-LA). Since lipoic acids inhibited PDKs activity both when reconstituted in PDC and in the presence of E1 alone, dissociation of PDK from the lipoyl domains of dihydrolipoamide acetyltransferase in the presence of lipoic acids is not a likely explanation for inhibition. The activity of PDK1 towards phosphorylation sites 1, 2 and 3 of E1 was decreased to the same extent in the presence of R-lipoic acid, thus excluding protection of the E1 active site by lipoic acid from phosphorylation. R-lipoic acid inhibited autophosphorylation of PDK2 indicating that it exerted its effect on PDKs directly. Inhibition of PDK1 by R-lipoic acid was not altered by ADP but was decreased in the presence of pyruvate which itself inhibits PDKs. An inhibitory effect of lipoic acid on PDKs would result in less phosphorylation of E1 and hence increased PDC activity. This finding provides a possible mechanism for a glucose (and lactate) lowering effect of R-lipoic acid in diabetic subjects.

  8. Recent advances in biotechnological applications of alcohol dehydrogenases.

    Science.gov (United States)

    Zheng, Yu-Guo; Yin, Huan-Huan; Yu, Dao-Fu; Chen, Xiang; Tang, Xiao-Ling; Zhang, Xiao-Jian; Xue, Ya-Ping; Wang, Ya-Jun; Liu, Zhi-Qiang

    2017-02-01

    Alcohol dehydrogenases (ADHs), which belong to the oxidoreductase superfamily, catalyze the interconversion between alcohols and aldehydes or ketones with high stereoselectivity under mild conditions. ADHs are widely employed as biocatalysts for the dynamic kinetic resolution of racemic substrates and for the preparation of enantiomerically pure chemicals. This review provides an overview of biotechnological applications for ADHs in the production of chiral pharmaceuticals and fine chemicals.

  9. Xanthine dehydrogenase-1 silencing in Aedes aegypti mosquitoes promotes a blood feeding-induced adulticidal activity.

    Science.gov (United States)

    Isoe, Jun; Petchampai, Natthida; Isoe, Yurika E; Co, Katrina; Mazzalupo, Stacy; Scaraffia, Patricia Y

    2017-02-08

    Aedesaegypti has 2 genes encoding xanthine dehydrogenase (XDH). We analyzed XDH1 and XDH2 gene expression by real-time quantitative PCR in tissues from sugar- and blood-fed females. Differential XDH1 and XDH2 gene expression was observed in tissues dissected throughout a time course. We next exposed females to blood meals supplemented with allopurinol, a well-characterized XDH inhibitor. We also tested the effects of injecting double-stranded RNA (dsRNA) against XDH1, XDH2, or both. Disruption of XDH by allopurinol or XDH1 by RNA interference significantly affected mosquito survival, causing a disruption in blood digestion, excretion, oviposition, and reproduction. XDH1-deficient mosquitoes showed a persistence of serine proteases in the midgut at 48 h after blood feeding and a reduction in the uptake of vitellogenin by the ovaries. Surprisingly, analysis of the fat body from dsRNA-XDH1-injected mosquitoes fell into 2 groups: one group was characterized by a reduction of the XDH1 transcript, whereas the other group was characterized by an up-regulation of several transcripts including XDH1, glutamine synthetase, alanine aminotransferase, catalase, superoxide dismutase, ornithine decarboxylase, glutamate receptor, and ammonia transporter. Our data demonstrate that XDH1 plays an essential role and that XDH1 has the potential to be used as a metabolic target for Ae.aegypti vector control.-Isoe, J., Petchampai, N., Isoe, Y. E., Co, K., Mazzalupo, S., Scaraffia, P. Y. Xanthine dehydrogenase-1 silencing in Aedes aegypti mosquitoes promotes a blood feeding-induced adulticidal activity.

  10. The 6-phosphogluconate Dehydrogenase Genes Are Responsive to Abiotic Stresses in Rice

    Institute of Scientific and Technical Information of China (English)

    Fu-Yun Hou; Ji Huang; Shan-Lin Yu; Hong-Sheng Zhang

    2007-01-01

    Glucose-6-phosphate dehydrogenase (G6PDH, E.C. 1.1.1.49) and 6-phosphogluconate dehydrogenase (6PGDH, EC 1.1.1.44) are both key enzymes of the pentose phosphate pathway (PPP). The OsG6PDH1 and Os6PGDH1 genes encoding cytosolic G6PDH and cytosolic 6PGDH were isoiated from rice (Oryza satlva L.). We have shown that Os6PGDH1 gene was up-regulated by salt stress. Here we reported the isolation and characterization of Os6PGDH2 from rice, which encode the plastidic counterpart of 6PGDH. Genomic organization analysis indicated that OsG6PDH1 and OsG6PDH2 genes contain multiple introns, whereas two Os6PGDH1 and Os6PGDH2 genes have no introns in their translated regions. In a step towards understanding the functions of the pentose phosphate pathway in plants in response to various abiotic stresses, the expressions of four genes in the rice seedlings treated by drought, cold, high salinity and abscisic acid (ABA) were investigated. The results show that OsG6PDH1 and OsG6PDH2 are not markedly regulated by the abiotic stresses detected. However, the transcript levels of both Os6PGDH1 and Os6PGDH2 are up-regulated in rice seedlings under drought, cold, high salinity and ABA treatments. Meanwhile,the enzyme activities of G6PDH and 6PGDH in the rice seedlings treated by various ablotlc stresses were investigated.Like the mRNA expression patterns, G6PDH activity remains constant but the 6PGDH increases steadily during the treatments. Taken together, we suggest that the pentose phosphate pathway may play an important role in rice responses to abiotlc stresses and the second key enzyme of PPP, 6PGDH, may function as a regulator controlling the efficiency of the pathway under abiotic stresses.

  11. Sperm-Specific Glyceraldehyde-3-Phosphate Dehydrogenase - An Evolutionary Acquisition of Mammals.

    Science.gov (United States)

    Muronetz, V I; Kuravsky, M L; Barinova, K V; Schmalhausen, E V

    2015-12-01

    This review is focused on the mammalian sperm-specific glyceraldehyde-3-phosphate dehydrogenase (GAPDS). GAPDS plays the major role in the production of energy required for sperm cell movement and does not perform non-glycolytic functions that are characteristic of the somatic isoenzyme of glyceraldehyde-3-phosphate dehydrogenase. The GAPDS sequence is composed of 408 amino acid residues and includes an additional N-terminal region of 72 a.a. that binds the protein to the sperm tail cytoskeleton. GAPDS is present only in the sperm cells of mammals and lizards, possibly providing them with certain evolutionary advantages in reproduction. In this review, studies concerning the problems of GAPDS isolation, its catalytic properties, and its structural features are described in detail. GAPDS is much more stable compared to the somatic isoenzyme, perhaps due to the necessity of maintaining the enzyme function in the absence of protein expression. The site-directed mutagenesis approach revealed the two GAPDS-specific proline residues, as well as three salt bridges, which seem to be the basis of the increased stability of this protein. As distinct from the somatic isoenzyme, GAPDS exhibits positive cooperativity in binding of the coenzyme NAD+. The key role in transduction of structural changes induced by NAD+ is played by the salt bridge D311-H124. Disruption of this salt bridge cancels GAPDS cooperativity and twofold increases its enzymatic activity instead. The expression of GAPDS was detected in some melanoma cells as well. Its role in the development of certain pathologies, such as cancer and neurodegenerative diseases, is discussed.

  12. Identification of Tumor Endothelial Cells with High Aldehyde Dehydrogenase Activity and a Highly Angiogenic Phenotype

    Science.gov (United States)

    Maishi, Nako; Ohga, Noritaka; Hida, Yasuhiro; Kawamoto, Taisuke; Iida, Junichiro; Shindoh, Masanobu; Tsuchiya, Kunihiko; Shinohara, Nobuo; Hida, Kyoko

    2014-01-01

    Tumor blood vessels play an important role in tumor progression and metastasis. It has been reported that tumor endothelial cells (TECs) exhibit highly angiogenic phenotypes compared with those of normal endothelial cells (NECs). TECs show higher proliferative and migratory abilities than those NECs, together with upregulation of vascular endothelial growth factor (VEGF) and VEGF receptor 2 (VEGFR2). Furthermore, compared with NECs, stem cell markers such as Sca-1, CD90, and multidrug resistance 1 are upregulated in TECs, suggesting that stem-like cells exist in tumor blood vessels. In this study, to reveal the biological role of stem-like TECs, we analyzed expression of the stem cell marker aldehyde dehydrogenase (ALDH) in TECs and characterized ALDHhigh TECs. TECs and NECs were isolated from melanoma-xenografted nude mice and normal dermis, respectively. ALDH mRNA expression and activity were higher in TECs than those in NECs. Next, ALDHhigh/low TECs were isolated by fluorescence-activated cell sorting to compare their characteristics. Compared with ALDHlow TECs, ALDHhigh TECs formed more tubes on Matrigel-coated plates and sustained the tubular networks longer. Furthermore, VEGFR2 expression was higher in ALDHhigh TECs than that in ALDHlow TECs. In addition, ALDH was expressed in the tumor blood vessels of in vivo mouse models of melanoma and oral carcinoma, but not in normal blood vessels. These findings indicate that ALDHhigh TECs exhibit an angiogenic phenotype. Stem-like TECs may have an essential role in tumor angiogenesis. PMID:25437864

  13. Identification of tumor endothelial cells with high aldehyde dehydrogenase activity and a highly angiogenic phenotype.

    Directory of Open Access Journals (Sweden)

    Hitomi Ohmura-Kakutani

    Full Text Available Tumor blood vessels play an important role in tumor progression and metastasis. It has been reported that tumor endothelial cells (TECs exhibit highly angiogenic phenotypes compared with those of normal endothelial cells (NECs. TECs show higher proliferative and migratory abilities than those NECs, together with upregulation of vascular endothelial growth factor (VEGF and VEGF receptor 2 (VEGFR2. Furthermore, compared with NECs, stem cell markers such as Sca-1, CD90, and multidrug resistance 1 are upregulated in TECs, suggesting that stem-like cells exist in tumor blood vessels. In this study, to reveal the biological role of stem-like TECs, we analyzed expression of the stem cell marker aldehyde dehydrogenase (ALDH in TECs and characterized ALDHhigh TECs. TECs and NECs were isolated from melanoma-xenografted nude mice and normal dermis, respectively. ALDH mRNA expression and activity were higher in TECs than those in NECs. Next, ALDHhigh/low TECs were isolated by fluorescence-activated cell sorting to compare their characteristics. Compared with ALDHlow TECs, ALDHhigh TECs formed more tubes on Matrigel-coated plates and sustained the tubular networks longer. Furthermore, VEGFR2 expression was higher in ALDHhigh TECs than that in ALDHlow TECs. In addition, ALDH was expressed in the tumor blood vessels of in vivo mouse models of melanoma and oral carcinoma, but not in normal blood vessels. These findings indicate that ALDHhigh TECs exhibit an angiogenic phenotype. Stem-like TECs may have an essential role in tumor angiogenesis.

  14. Overexpression of glucose-6-phosphate dehydrogenase is associated with lipid dysregulation and insulin resistance in obesity.

    Science.gov (United States)

    Park, Jiyoung; Rho, Ho Kyung; Kim, Kang Ho; Choe, Sung Sik; Lee, Yun Sok; Kim, Jae Bum

    2005-06-01

    Glucose-6-phosphate dehydrogenase (G6PD) produces cellular NADPH, which is required for the biosynthesis of fatty acids and cholesterol. Although G6PD is required for lipogenesis, it is poorly understood whether G6PD in adipocytes is involved in energy homeostasis, such as lipid and glucose metabolism. We report here that G6PD plays a role in adipogenesis and that its increase is tightly associated with the dysregulation of lipid metabolism and insulin resistance in obesity. We observed that the enzymatic activity and expression levels of G6PD were significantly elevated in white adipose tissues of obese models, including db/db, ob/ob, and diet-induced obesity mice. In 3T3-L1 cells, G6PD overexpression stimulated the expression of most adipocyte marker genes and elevated the levels of cellular free fatty acids, triglyceride, and FFA release. Consistently, G6PD knockdown via small interfering RNA attenuated adipocyte differentiation with less lipid droplet accumulation. Surprisingly, the expression of certain adipocytokines such as tumor necrosis factor alpha and resistin was increased, whereas that of adiponectin was decreased in G6PD overexpressed adipocytes. In accordance with these results, overexpression of G6PD impaired insulin signaling and suppressed insulin-dependent glucose uptake in adipocytes. Taken together, these data strongly suggest that aberrant increase of G6PD in obese and/or diabetic subjects would alter lipid metabolism and adipocytokine expression, thereby resulting in failure of lipid homeostasis and insulin resistance in adipocytes.

  15. Nicotine promotes Streptococcus mutans extracellular polysaccharide synthesis, cell aggregation and overall lactate dehydrogenase activity.

    Science.gov (United States)

    Huang, R; Li, M; Gregory, R L

    2015-08-01

    Several epidemiology studies have reported a positive relationship between smoking and dental caries. Nicotine, an alkaloid component of tobacco, has been demonstrated to stimulate biofilm formation and metabolic activity of Streptococcus mutans, one of the most important pathogens of dental caries. The first aim of the present study was to explore the possible mechanisms leading to increased biofilm by nicotine treatment from three aspects, extracellular polysaccharides (EPS) synthesis, glucosyltransferase (Gtf) synthesis and glucan-binding protein (Gbp) synthesis at the mRNA and protein levels. The second aim was to investigate how nicotine affects S. mutans virulence, particular in lactate dehydrogenase (LDH) activity. Confocal laser scanning microscopy results demonstrated that both biofilm bacterial cell numbers and EPS were increased by nicotine. Gtf and GbpA protein expression of S. mutans planktonic cells were upregulated while GbpB protein expression of biofilm cells were downregulated by nicotine. The mRNA expression trends of those genes were mostly consistent with results on protein level but not statistically significant, and gtfD and gbpD of biofilm cells were inhibited. Nicotine was not directly involved in S. mutans LDH activity. However, since it increases the total number of bacterial cells in biofilm, the overall LDH activity of S. mutans biofilm is increased. In conclusion, nicotine stimulates S. mutans planktonic cell Gtf and Gbp expression. This leads to more planktonic cells attaching to the dental biofilm. Increased cell numbers within biofilm results in higher overall LDH activity. This contributes to caries development in smokers.

  16. Telomerase prevents accelerated senescence in glucose-6-phosphate dehydrogenase (G6PD-deficient human fibroblasts

    Directory of Open Access Journals (Sweden)

    Wu Yi-Hsuan

    2009-02-01

    Full Text Available Abstract Fibroblasts derived from glucose-6-phosphate dehydrogenase (G6PD-deficient patients display retarded growth and accelerated cellular senescence that is attributable to increased accumulation of oxidative DNA damage and increased sensitivity to oxidant-induced senescence, but not to accelerated telomere attrition. Here, we show that ectopic expression of hTERT stimulates telomerase activity and prevents accelerated senescence in G6PD-deficient cells. Stable clones derived from hTERT-expressing normal and G6PD-deficient fibroblasts have normal karyotypes, and display no sign of senescence beyond 145 and 105 passages, respectively. Activation of telomerase, however, does not prevent telomere attrition in earlier-passage cells, but does stabilize telomere lengths at later passages. In addition, we provide evidence that ectopic expression of hTERT attenuates the increased sensitivity of G6PD-deficient fibroblasts to oxidant-induced senescence. These results suggest that ectopic expression of hTERT, in addition to acting in telomere length maintenance by activating telomerase, also functions in regulating senescence induction.

  17. Glyceraldehyde-3-phosphate dehydrogenase: a universal internal control for Western blots in prokaryotic and eukaryotic cells.

    Science.gov (United States)

    Wu, Yonghong; Wu, Min; He, Guowei; Zhang, Xiao; Li, Weiguang; Gao, Yan; Li, Zhihui; Wang, Zhaoyan; Zhang, Chenggang

    2012-04-01

    In the current study, we examined the expression level of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) protein in a number of organisms and the stability of GAPDH under various conditions. Our results revealed that GAPDH is present in multiple Escherichia coli strains, the yeast strain GS115, Caenorhabditis elegans, rat PC12 cells, and both mouse and rat brain. Furthermore, GAPDH was stably expressed under different concentrations of inducer and at different times of induction in E. coli (BL21) cells and yeast GS115 cells. Stable expression of GAPDH protein was also observed in C.elegans and PC12 cells that were treated with different concentrations of paraquat or sodium sulfite, respectively. In addition, we were able to detect and identify the endogenous gapA protein in E.coli via immunoprecipitation and MALDI-TOF-MS analysis. Endogenous gapA protein and exogenously expressed (subcloned) GAPDH proteins were detected in E. coli BL21 but not for gapC. With the exception of gapC in E. coli, the various isoforms of GAPDH possessed enzymatic activity. Finally, sequence analysis revealed that the GAPDH proteins were 76% identical, with the exception of E. coli gapC. Taken together, our results indicate that GAPDH could be universally used as an internal control for the Western blot analysis of prokaryotic and eukaryotic samples.

  18. Daidzin: a potent, selective inhibitor of human mitochondrial aldehyde dehydrogenase.

    Science.gov (United States)

    Keung, W M; Vallee, B L

    1993-02-15

    Human mitochondrial aldehyde dehydrogenase (ALDH-I) is potently, reversibly, and selectively inhibited by an isoflavone isolated from Radix puerariae and identified as daidzin, the 7-glucoside of 4',7-dihydroxyisoflavone. Kinetic analysis with formaldehyde as substrate reveals that daidzin inhibits ALDH-I competitively with respect to formaldehyde with a Ki of 40 nM, and uncompetitively with respect to the coenzyme NAD+. The human cytosolic aldehyde dehydrogenase isozyme (ALDH-II) is nearly 3 orders of magnitude less sensitive to daidzin inhibition. Daidzin does not inhibit human class I, II, or III alcohol dehydrogenases, nor does it have any significant effect on biological systems that are known to be affected by other isoflavones. Among more than 40 structurally related compounds surveyed, 12 inhibit ALDH-I, but only prunetin and 5-hydroxydaidzin (genistin) combine high selectivity and potency, although they are 7- to 15-fold less potent than daidzin. Structure-function relationships have established a basis for the design and synthesis of additional ALDH inhibitors that could both be yet more potent and specific.

  19. Purification, crystallization and preliminary X-ray analysis of bifunctional isocitrate dehydrogenase kinase/phosphatase in complex with its substrate, isocitrate dehydrogenase, from Escherichia coli

    OpenAIRE

    2009-01-01

    The protein complex of bifunctional isocitrate dehydrogenase kinase/phosphatase with its substrate, isocitrate dehydrogenase, has been crystallized for structural analysis. A complete data set was collected from the complex crystal and processed to 2.9 Å resolution.

  20. Use of a modified alcohol dehydrogenase, ADH1, promoter in construction of diacetyl non-producing brewer's yeast.

    Science.gov (United States)

    Onnela, M L; Suihko, M L; Penttilä, M; Keränen, S

    1996-08-20

    The bacterial gene, encoding alpha-acetolactate decarboxylase (alpha-ALDC), was expressed in a bottom-fermenting brewer's yeast under the control of a modified Saccharomyces cerevisiae alcohol dehydrogenase (ADH1) promoter which lacks the upstream regions from -800 bp to -1500 bp. In pilot scale brewing conditions, the level of alpha-ALDC produced was high enough to reduce the concentration of diacetyl so that lagering was not required. alpha-ALDC active brewer's yeast strains were also shown to be suitable for high gravity brewing.

  1. Isocitrate dehydrogenase 1 Gene Mutation Is Associated with Prognosis in Clinical Low-Grade Gliomas.

    Directory of Open Access Journals (Sweden)

    Ming-Yang Li

    Full Text Available Isocitrate dehydrogenase 1 gene mutations are found in most World Health Organization grade II and III gliomas and secondary glioblastomas. Isocitrate dehydrogenase 1 mutations are known to have prognostic value in high-grade gliomas. However, their prognostic significance in low-grade gliomas remains controversial. We determined the predictive and prognostic value of isocitrate dehydrogenase 1 status in low-grade gliomas. The association of isocitrate dehydrogenase 1 status with clinicopathological and genetic factors was also evaluated. Clinical information and genetic data including isocitrate dehydrogenase 1 mutation, O 6-methylguanine DNA methyltransferase promoter methylation, 1p/19q chromosome loss, and TP53 mutation of 417 low-grade gliomas were collected from the Chinese Glioma Genome Atlas database. Kaplan-Meier and Cox proportional hazards regression analyses were performed to evaluate the prognostic effect of clinical characteristics and molecular biomarkers. Isocitrate dehydrogenase 1 mutation was identified as an independent prognostic factor for overall, but not progression-free, survival. Notably, isocitrate dehydrogenase 1 mutation was found to be a significant prognostic factor in patients with oligodendrogliomas, but not in patients with astrocytomas. Furthermore, O 6-methylguanine DNA methyltransferase promoter methylation (p = 0.017 and TP53 mutation (p < 0.001, but not 1p/19q loss (p = 0.834, occurred at a higher frequency in isocitrate dehydrogenase 1-mutated tumors than in isocitrate dehydrogenase 1 wild-type tumors. Younger patient age (p = 0.041 and frontal lobe location (p = 0.010 were significantly correlated with isocitrate dehydrogenase 1 mutation. Chemotherapy did not provide a survival benefit in patients with isocitrate dehydrogenase 1-mutated tumors. Isocitrate dehydrogenase 1 mutation was an independent prognostic factor in low-grade gliomas, whereas it showed no predictive value for chemotherapy response

  2. Isocitrate dehydrogenase 1 Gene Mutation Is Associated with Prognosis in Clinical Low-Grade Gliomas.

    Science.gov (United States)

    Li, Ming-Yang; Wang, Yin-Yan; Cai, Jin-Quan; Zhang, Chuan-Bao; Wang, Kuan-Yu; Cheng, Wen; Liu, Yan-Wei; Zhang, Wei; Jiang, Tao

    2015-01-01

    Isocitrate dehydrogenase 1 gene mutations are found in most World Health Organization grade II and III gliomas and secondary glioblastomas. Isocitrate dehydrogenase 1 mutations are known to have prognostic value in high-grade gliomas. However, their prognostic significance in low-grade gliomas remains controversial. We determined the predictive and prognostic value of isocitrate dehydrogenase 1 status in low-grade gliomas. The association of isocitrate dehydrogenase 1 status with clinicopathological and genetic factors was also evaluated. Clinical information and genetic data including isocitrate dehydrogenase 1 mutation, O 6-methylguanine DNA methyltransferase promoter methylation, 1p/19q chromosome loss, and TP53 mutation of 417 low-grade gliomas were collected from the Chinese Glioma Genome Atlas database. Kaplan-Meier and Cox proportional hazards regression analyses were performed to evaluate the prognostic effect of clinical characteristics and molecular biomarkers. Isocitrate dehydrogenase 1 mutation was identified as an independent prognostic factor for overall, but not progression-free, survival. Notably, isocitrate dehydrogenase 1 mutation was found to be a significant prognostic factor in patients with oligodendrogliomas, but not in patients with astrocytomas. Furthermore, O 6-methylguanine DNA methyltransferase promoter methylation (p = 0.017) and TP53 mutation (p isocitrate dehydrogenase 1-mutated tumors than in isocitrate dehydrogenase 1 wild-type tumors. Younger patient age (p = 0.041) and frontal lobe location (p = 0.010) were significantly correlated with isocitrate dehydrogenase 1 mutation. Chemotherapy did not provide a survival benefit in patients with isocitrate dehydrogenase 1-mutated tumors. Isocitrate dehydrogenase 1 mutation was an independent prognostic factor in low-grade gliomas, whereas it showed no predictive value for chemotherapy response. Isocitrate dehydrogenase 1 mutation was highly associated with O 6-methylguanine DNA

  3. High substrate specificity of ipsdienol dehydrogenase (IDOLDH), a short-chain dehydrogenase from Ips pini bark beetles.

    Science.gov (United States)

    Figueroa-Teran, Rubi; Pak, Heidi; Blomquist, Gary J; Tittiger, Claus

    2016-09-01

    Ips spp. bark beetles use ipsdienol, ipsenol, ipsdienone and ipsenone as aggregation pheromone components and pheromone precursors. For Ips pini, the short-chain oxidoreductase ipsdienol dehydrogenase (IDOLDH) converts (-)-ipsdienol to ipsdienone, and thus likely plays a role in determining pheromone composition. In order to further understand the role of IDOLDH in pheromone biosynthesis, we compared IDOLDH to its nearest functionally characterized ortholog with a solved structure: human L-3-hydroxyacyl-CoA dehydrogenase type II/ amyloid-β binding alcohol dehydrogenase (hHADH II/ABAD), and conducted functional assays of recombinant IDOLDH to determine substrate and product ranges and structural characteristics. Although IDOLDH and hHADH II/ABAD had only 35% sequence identity, their predicted tertiary structures had high identity. We found IDOLDH is a functional homo-tetramer. In addition to oxidizing (-)-ipsdienol, IDOLDH readily converted racemic ipsenol to ipsenone, and stereo-specifically reduced both ketones to their corresponding (-)-alcohols. The (+)-enantiomers were never observed as products. Assays with various substrate analogs showed IDOLDH had high substrate specificity for (-)-ipsdienol, ipsenol, ipsenone and ipsdienone, supporting that IDOLDH functions as a pheromone-biosynthetic enzyme. These results suggest that different IDOLDH orthologs and or activity levels contribute to differences in Ips spp. pheromone composition.

  4. 共转染小干扰RNA质粒联合抑制HeLa细胞葡萄糖-6-磷酸脱氢酶和转酮醇酶样基因-1表达%Combined inhibitory effect of co-transfected siRNA plasmids in Hela cells on the expressions of glucose-6-phosphate dehydrogenase and transketolase like-1

    Institute of Scientific and Technical Information of China (English)

    张德太; 杨文; 涂启明; 张科; 胡丽华

    2013-01-01

    目的 葡萄糖-6-磷酸脱氢酶(glucose-6-phosphate dehydrogenase, G6PD)及转酮醇酶样基因-1(transketolase like-1, TKTL-1)是肿瘤细胞磷酸戊糖代谢途径(pentose phosphate pathway, PPP)的2个重要关键调节酶.拟通过共转染小干扰RNA(small interfering RNA, siRNA)表达载体同时沉默人宫颈癌Hela G6PD及TKTL-1后,观察其对G6PD和TKTL1的联合抑制作用,旨在探讨共转染siRNA表达载体联合抑制PPP的效果及可行性.方法 分别构建靶向G6PD和TKTL1基因siRNA干扰质粒载体,通过酶切和测序鉴定siRNA干扰质粒载体构建成功后,单独或共转染HeLa细胞株,RT-PCR检测G6PD、TKTL1 mRNA表达并结合G6PD、转酮醇酶(transketolase, TKT)活性测定判断并比较共转染联合抑制Hela细胞G6PD、TKTL1表达的效果.结果 共转染靶向G6PD和TKTL1基因的siRNA干扰载体能显著下调G6PD和TKTL1基因表达水平[(0.96±0.05) vs (0.47±0.04),(0.98±0.05)vs(0.41±0.04), P<0.01].同时,2个酶的活性也显著下降(99.2%vs34.5%和99.8%vs40.1%, P<0.01).共转染抑制G6PD基因mRNA表达较单独转染靶向G6PD基因的siRNA干扰载体的效果有显著下降[(0.47±0.04 )vs(0.31±0.04), P<0.01)].结论 共转染siRNA干扰载体对人宫颈癌HeLa细胞PPP代谢通路进行联合抑制是一种有效的实验方案.

  5. 青海湖裸鲤三磷酸甘油醛脱氢酶基因的克隆和表达特性%Expression and cloning of two glyceraldehyde 3-phosphate dehydrogenase mRNAs from Gymnocypris przewalskii in Qinghai Lake

    Institute of Scientific and Technical Information of China (English)

    卫福磊; 李长忠; 史建全; 祁得林; 梁健; 谢保胜; 赵兰英; 祁洪芳

    2013-01-01

    Objective Gymnocypris przewalskii (naked carp) , a unique economic fish species distributed in Qinghai Lake and its periphery area on Qinghai-Tibet plateau , plays a key role in the ecosystem composed mainly of fish, birds and meadow. Research concerning Gymnocypris przewalskii biological characteristics and molecular mechanism adapted to hypoxia, low temperature and salinity stress will contribute to discovering the basic regular pattern of vital activity and provide theoretical support to conservation and artificial reproduction of this species. Methods In this study, two complete cDNA sequences of glyceraldehyde-3-phosphate dehydrogenase ( GPDH) paralogue isoforms, which were named as Gp-GAPDHα (JX287372) and Gp-GAPDHβ (JX287373) , respectively, were obtained from the naked carp through reverse transcriptase polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE). The transcription levels were determined based on semi-quantitative RT-PCR analysis. Results The transcription levels of Gp-GAPDHα and Gp-GAPDHβ were unstable in different organ tissues and during different periods of embryogenesis. Both two deduced nu-cleotide sequences have an identity of 72% , and show high similarity with GPDH sequences of other species. Most interestingly, Gp-GAPDHa displays a significant difference at different stages of embryogenesis. Conclusion Gp-GAPDHa is unsuitable to be used as a control for the molecular study in embryogenesis, and the functions of the paralogs need to be further confirmed.%目的 开展青海湖裸鲤基础生物学特征和适应低氧、低温、高盐度的分子机理的研究,揭示青海湖裸鲤的基本生命活动规律,为该鱼种的资源保护和人工增殖放流提供理论依据.方法通过RT-PCR和RACE技术,得到了青海湖裸鲤三磷酸甘油醛脱氢酶(Gp-GAPDH)两种旁系同源体的完整编码序列,分别命名为Gp-GAPDHα (JX287372)和Gp-GAPDHβ (JX287373).通过半定量RT-PCR分析Gp-GAPDHα

  6. Toxic response caused by a misfolding variant of the mitochondrial protein short-chain acyl-CoA dehydrogenase

    DEFF Research Database (Denmark)

    Schmidt, Stinne P; Corydon, Thomas J; Pedersen, Christina B;

    2011-01-01

    the disease-associated misfolding variant of SCAD protein, p.Arg107Cys, disturbs mitochondrial function. METHODS: We have developed a cell model system, stably expressing either the SCAD wild-type protein or the misfolding SCAD variant protein, p.Arg107Cys (c.319 C > T). The model system was used......BACKGROUND: Variations in the gene ACADS, encoding the mitochondrial protein short-chain acyl CoA-dehydrogenase (SCAD), have been observed in individuals with clinical symptoms. The phenotype of SCAD deficiency (SCADD) is very heterogeneous, ranging from asymptomatic to severe, without a clear...... for investigation of SCAD with respect to expression, degree of misfolding, and enzymatic SCAD activity. Furthermore, cell proliferation and expression of selected stress response genes were investigated as well as proteomic analysis of mitochondria-enriched extracts in order to study the consequences of p.Arg107...

  7. CcpA-independent glucose regulation of lactate dehydrogenase 1 in Staphylococcus aureus.

    Directory of Open Access Journals (Sweden)

    Adrianne K Crooke

    Full Text Available Lactate Dehydrogenase 1 (Ldh1 is a key enzyme involved in Staphylococcus aureus NO·-resistance. Full ldh1-induction requires the presence of glucose, and mutants lacking the Carbon-Catabolite Protein (CcpA exhibit decreased ldh1 transcription and diminished Ldh1 activity. The redox-regulator Rex represses ldh1 directly by binding to Rex-sites within the ldh1 promoter (P(ldh1. In the absence of Rex, neither glucose nor CcpA affect ldh1 expression implying that glucose/CcpA-mediated activation requires Rex activity. Rex-mediated repression of ldh1 depends on cellular redox status and is maximal when NADH levels are low. However, compared to WT cells, the ΔccpA mutant exhibited impaired redox balance with relatively high NADH levels, yet ldh1 was still poorly expressed. Furthermore, CcpA did not drastically alter Rex transcript levels, nor did glucose or CcpA affect the expression of other Rex-regulated genes indicating that the glucose/CcpA effect is specific for P(ldh1. A putative catabolite response element (CRE is located ∼30 bp upstream of the promoter-distal Rex-binding site in P(ldh1. However, CcpA had no affinity for P(ldh1 in vitro and a genomic mutation of CRE upstream of P(ldh1 in S. aureus had no affect on Ldh1 expression in vivo. In contrast to WT, ΔccpA S. aureus preferentially consumes non-glycolytic carbon sources. However when grown in defined medium with glucose as the primary carbon source, ΔccpA mutants express high levels of Ldh1 compared to growth in media devoid of glucose. Thus, the actual consumption of glucose stimulates Ldh1 expression rather than direct CcpA interaction at P(ldh1.

  8. Aldehyde dehydrogenase activity selects for lung adenocarcinoma stem cells dependent on notch signaling.

    Science.gov (United States)

    Sullivan, James P; Spinola, Monica; Dodge, Michael; Raso, Maria G; Behrens, Carmen; Gao, Boning; Schuster, Katja; Shao, Chunli; Larsen, Jill E; Sullivan, Laura A; Honorio, Sofia; Xie, Yang; Scaglioni, Pier P; DiMaio, J Michael; Gazdar, Adi F; Shay, Jerry W; Wistuba, Ignacio I; Minna, John D

    2010-12-01

    Aldehyde dehydrogenase (ALDH) is a candidate marker for lung cancer cells with stem cell-like properties. Immunohistochemical staining of a large panel of primary non-small cell lung cancer (NSCLC) samples for ALDH1A1, ALDH3A1, and CD133 revealed a significant correlation between ALDH1A1 (but not ALDH3A1 or CD133) expression and poor prognosis in patients including those with stage I and N0 disease. Flow cytometric analysis of a panel of lung cancer cell lines and patient tumors revealed that most NSCLCs contain a subpopulation of cells with elevated ALDH activity, and that this activity is associated with ALDH1A1 expression. Isolated ALDH(+) lung cancer cells were observed to be highly tumorigenic and clonogenic as well as capable of self-renewal compared with their ALDH(-) counterparts. Expression analysis of sorted cells revealed elevated Notch pathway transcript expression in ALDH(+) cells. Suppression of the Notch pathway by treatment with either a γ-secretase inhibitor or stable expression of shRNA against NOTCH3 resulted in a significant decrease in ALDH(+) lung cancer cells, commensurate with a reduction in tumor cell proliferation and clonogenicity. Taken together, these findings indicate that ALDH selects for a subpopulation of self-renewing NSCLC stem-like cells with increased tumorigenic potential, that NSCLCs harboring tumor cells with ALDH1A1 expression have inferior prognosis, and that ALDH1A1 and CD133 identify different tumor subpopulations. Therapeutic targeting of the Notch pathway reduces this ALDH(+) component, implicating Notch signaling in lung cancer stem cell maintenance.

  9. Gain of interaction of ALS-linked G93A superoxide dismutase with cytosolic malate dehydrogenase.

    Science.gov (United States)

    Mali, Yael; Zisapels, Nava

    2008-10-01

    Protein interactions of the Amyotrophic Lateral Sclerosis (ALS)-linked copper-zinc superoxide dismutase (hSOD1) G93A mutation were studied using a fluorescence resonance energy transfer (FRET) based screening system. The FRET results confirmed by pull-down immunoprecipitation indicated "gain-of-interaction" of the G93A-hSOD1 mutant with cytosolic malate dehydrogenase (cytMDH)-a key enzyme in the malate-aspartate shuttle which is vital to neurons. Furthermore, cytMDH mRNA expression was upregulated in G93A-hSOD1 expressing cells but endogenous cytMDH enzymatic activity was not enhanced, not even with exogenously added-on enzyme. Consistent with inhibition of the malate-aspartate shuttle, G93A-hSOD1 had lower malate and higher lactate levels compared to non-induced or Wild-Type-hSOD1 expressing cells. Mitochondrial NADH/NAD+ ratio is also elevated. Malate-aspartate shuttle dysfunction may explain the damage to neurons and the vulnerability to impairments of glycolytic pathways in ALS and provide a new target for the development of potential therapies.

  10. One-step purification of soluble recombinant human 6-phosphogluconate dehydrogenase from Escherichia coli.

    Science.gov (United States)

    Chan, Barden; Sukhatme, Vikas P

    2013-11-01

    6-Phosphogluconate dehydrogenase (6PGD), the third enzyme in the pentose phosphate pathway, was recently identified as a novel target in human lung cancer. In this report, we present an expression and purification scheme of recombinant human 6PGD from Escherichia coli. Using a DE3 derivative strain expressing tRNAs for seven rare codons in E. coli called Rosetta2 (DE3), a large quantity of soluble human 6PGD can be expressed with an N-terminal histidine tag and purified by a one-step purification procedure to near homogeneity without denaturants or refolding. Three to seven milligrams of purified protein could be obtained from 100 ml of culture. This recombinant human 6PGD follows classic Michaelis-Menton saturation kinetics with respect to both substrates NADP(+) and 6-phosphogluconate. The respective k(cat) and K(m) were comparable to those of 6PGDs purified from mammalian tissues. Using this purified 6PGD enzyme, we devised an endpoint colorimetric assay suitable for high-throughput screening for human 6PGD inhibitors.

  11. Application of NAD-dependent polyol dehydrogenases for enzymatic mannitol/sorbitol production with coenzyme regeneration.

    Science.gov (United States)

    Parmentier, S; Arnaut, F; Soetaert, W; Vandamme, E J

    2003-01-01

    D-Mannitol and D-sorbitol were produced enzymatically from D-fructose using NAD-dependent polyol dehydrogenases. For the production of D-mannitol the Leuconostoc mesenteroides mannitol dehydrogenase could be used. Gluconobacter oxydans cell extract contained however both mannitol and sorbitol dehydrogenase. When this cell extract was used, the reduction of D-fructose resulted in a mixture of D-sorbitol and D-mannitol. To determine the optimal bioconversion conditions the polyol dehydrogenases were characterized towards pH- and temperature-optimum and -stability. As a compromise between enzyme activity and stability, the bioconversion reactions were performed at pH 6.5 and 25 degrees C. Since the polyol dehydrogenases are NADH-dependent, an efficient coenzyme regeneration was needed. Regeneration of NADH was accomplished by formate dehydrogenase-mediated oxidation of formate into CO2.

  12. 甜菜碱合成酶CMO、BADH基因无抗生素标记植物表达载体的构建%Construction of Non-antibiotic Maker Plant Expression Vector on Choline Monooxygenase and Betaine Aldehyde Dehydrogenase Gene

    Institute of Scientific and Technical Information of China (English)

    邓川; 高翎; 张君; 宋冰; 王丕武

    2011-01-01

    利用基因工程技术,对植物表达载体进行改造,去除NptⅡ、Hyg等抗生素标记,获得安全载体骨架,分别构建了无抗生素选择标记的CMO、BADH以及双价基因的植物表达载体pROK-CMO、pCAMBIA-1301-BADH 1、pCAMBIA-1301-CMO+BADH.通过冻融法将其转入根癌农杆菌LBA 4404中得到工程菌株,为下一步安全转化奠定基础.%By the genetic engineering technology, plant expression vectors were reconstructed to form a safe carrier skeleton, which were knocked out the antibiotic markers genes, such as NptII and Hyg. The Non-antibiotic maker Plant Expression Vectors with CMO or BADH gene were constructed respectively. Together with dual price of the plant expression vectors such as pROK-CMO, pCAMBIA-1301-BADH 1, pCAMBIA-1301-CMO + BADH were constructed later. The freeze-thaw method was used to transfer these vectors into the agrobaeterium strain LBA 4404 in order to acquire the engineering bacteria and laid the foundation for the security transformation of the next step.

  13. Resveratrol inhibits 11β-hydroxysteroid dehydrogenase type 1 activity in rat adipose microsomes.

    Science.gov (United States)

    Tagawa, Noriko; Kubota, Sayaka; Kato, Ikuo; Kobayashi, Yoshiharu

    2013-09-01

    It has been suggested that resveratrol, a polyphenol in wine, can regulate adiposity because it decreases adipose deposition in mice and rats; however, the mechanism underlying this effect has not been fully clarified. In humans and rodents, 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) is expressed in liver and adipose tissue. 11β-HSD1 converts inactive glucocorticoid into active glucocorticoid in adipocytes. Activated glucocorticoid plays an important role in the pathogenesis of central obesity. The objective of this study was to investigate the effects of resveratrol on 11β-HSD1 activity in rodent adipose tissue. 11β-HSD1 activity in microsomes from rat mesenteric adipose depots and 3T3-L1 adipocytes was determined in the presence of 11-dehydrocorticosterone with or without varying concentrations of resveratrol. Significant inhibition of 11β-HSD1 by resveratrol was observed in rat adipose microsomes and 3T3-L1 adipocytes within 10 min. Time- and dose-dependent effects were also observed. The 11β-HSD1 activity by resveratrol was also inhibited in rat epididymal adipose tissue, and this inhibition was not recovered by estrogen receptor blockers. The kinetic study revealed that resveratrol acted as a non-competitive inhibitor of 11β-HSD1. Ki and IC50 values of resveratrol were 39.6 and 35.2 μM respectively. Further, resveratrol did not affect the activities of 11β-HSD2 and hexose-6-phosphate dehydrogenase. These results suggest that the most likely mechanism of 11β-HSD1 inhibition by resveratrol is via interaction between resveratrol and 11β-HSD1 enzyme, rather than via a transcriptional pathway. We demonstrated that the antiobesity effects of resveratrol may partially be attributed to the inhibition of 11β-HSD1 activity in adipocytes.

  14. Kinetic properties and metabolic contributions of yeast mitochondrial and cytosolic NADP+-specific isocitrate dehydrogenases.

    Science.gov (United States)

    Contreras-Shannon, Veronica; Lin, An-Ping; McCammon, Mark T; McAlister-Henn, Lee

    2005-02-11

    To compare kinetic properties of homologous isozymes of NADP+-specific isocitrate dehydrogenase, histidine-tagged forms of yeast mitochondrial (IDP1) and cytosolic (IDP2) enzymes were expressed and purified. The isozymes were found to share similar apparent affinities for cofactors. However, with respect to isocitrate, IDP1 had an apparent Km value approximately 7-fold lower than that of IDP2, whereas, with respect to alpha-ketoglutarate, IDP2 had an apparent Km value approximately 10-fold lower than that of IDP1. Similar Km values for substrates and cofactors in decarboxylation and carboxylation reactions were obtained for IDP2, suggesting a capacity for bidirectional catalysis in vivo. Concentrations of isocitrate and alpha-ketoglutarate measured in extracts from the parental strain were found to be similar with growth on different carbon sources. For mutant strains lacking IDP1, IDP2, and/or the mitochondrial NAD+-specific isocitrate dehydrogenase (IDH), metabolite measurements indicated that major cellular flux is through the IDH-catalyzed reaction in glucose-grown cells and through the IDP2-catalyzed reaction in cells grown with a nonfermentable carbon source (glycerol and lactate). A substantial cellular pool of alpha-ketoglutarate is attributed to IDH function during glucose growth, and to both IDP1 and IDH function during growth on glycerol/lactate. Complementation experiments using a strain lacking IDH demonstrated that overexpression of IDP1 partially compensated for the glutamate auxotrophy associated with loss of IDH. Collectively, these results suggest an ancillary role for IDP1 in cellular glutamate synthesis and a role for IDP2 in equilibrating and maintaining cellular levels of isocitrate and alpha-ketoglutarate.

  15. [Dihydropirymidine dehydrogenase (DPD)--a toxicity marker for 5-fluorouracil?].

    Science.gov (United States)

    Jedrzychowska, Adriana; Dołegowska, Barbara

    2013-01-01

    In proceedings relating to patients suffering from cancer, an important step is predicting response and toxicity to treatment. Depending on the type of cancer, physicians use the generally accepted schema of treatment, for example pharmacotherapy. 5-fluorouracil (5-FU) is the most widely used anticancer drug in chemotherapy for colon, breast, and head and neck cancer. Patients with dihydropyrimidine dehydrogenase (DPD) deficiency, which is responsible for the metabolism of 5-FU, may experience severe side effects during treatment, and even death. In many publications the need for determining the activity of DPD is discussed, which would protect the patient from the numerous side effects of treatment. However, in practice these assays are not done routinely, despite the high demand. In most cases, a genetic test is used to detect changes in the gene encoding DPD (such as in the USA), but because of the large number of mutations the genetic test cannot be used as a screening test. Dihydropyrimidine dehydrogenase activity has been shown to have high variability among the general population, with an estimated proportion of at least 3-5% of individuals showing low or deficient DPD activity. In this publication we presents data about average dihydropirymidine dehydrogenase activity in various populations of the world (e.g. Japan, Ghana, Great Britain) including gender differences and collected information about the possibility of determination of DPD activity in different countries. Detection of reduced DPD activity in patients with planned chemotherapy will allow a lower dosage of 5-FU or alternative treatment without exposing them to adverse reactions.

  16. Identification, Cloning, and Characterization of l-Phenylserine Dehydrogenase from Pseudomonas syringae NK-15

    Directory of Open Access Journals (Sweden)

    Sakuko Ueshima

    2010-01-01

    Full Text Available The gene encoding d-phenylserine dehydrogenase from Pseudomonas syringae NK-15 was identified, and a 9,246-bp nucleotide sequence containing the gene was sequenced. Six ORFs were confirmed in the sequenced region, four of which were predicted to form an operon. A homology search of each ORF predicted that orf3 encoded l-phenylserine dehydrogenase. Hence, orf3 was cloned and overexpressed in Escherichia coli cells and recombinant ORF3 was purified to homogeneity and characterized. The purified ORF3 enzyme showed l-phenylserine dehydrogenase activity. The enzymological properties and primary structure of l-phenylserine dehydrogenase (ORF3 were quite different from those of d-phenylserine dehydrogenase previously reported. l-Phenylserine dehydrogenase catalyzed the NAD+-dependent oxidation of the β-hydroxyl group of l-β-phenylserine. l-Phenylserine and l-threo-(2-thienylserine were good substrates for l-phenylserine dehydrogenase. The genes encoding l-phenylserine dehydrogenase and d-phenylserine dehydrogenase, which is induced by phenylserine, are located in a single operon. The reaction products of both enzymatic reactions were 2-aminoacetophenone and CO2.

  17. Arteriovenous malformation within an isocitrate dehydrogenase 1 mutated anaplastic oligodendroglioma

    Directory of Open Access Journals (Sweden)

    Grace Lai

    2015-01-01

    Full Text Available Background: The co-occurrence of intracranial arteriovenous malformations (AVMs and cerebral neoplasms is exceedingly rare but may harbor implications pertaining to the molecular medicine of brain cancer pathogenesis. Case Description: Here, we present a case of de novo AVM within an isocitrate dehydrogenase 1 mutated anaplastic oligodendroglioma (WHO Grade III and review the potential contribution of this mutation to aberrant angiogenesis as an interesting case study in molecular medicine. Conclusion: The co-occurrence of an IDH1 mutated neoplasm and AVM supports the hypothesis that IDH1 mutations may contribute to aberrant angiogenesis and vascular malformation.

  18. Deracemization of Secondary Alcohols by using a Single Alcohol Dehydrogenase

    KAUST Repository

    Karume, Ibrahim

    2016-03-01

    © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. We developed a single-enzyme-mediated two-step approach for deracemization of secondary alcohols. A single mutant of Thermoanaerobacter ethanolicus secondary alcohol dehydrogenase enables the nonstereoselective oxidation of racemic alcohols to ketones, followed by a stereoselective reduction process. Varying the amounts of acetone and 2-propanol cosubstrates controls the stereoselectivities of the consecutive oxidation and reduction reactions, respectively. We used one enzyme to accomplish the deracemization of secondary alcohols with up to >99% ee and >99.5% recovery in one pot and without the need to isolate the prochiral ketone intermediate.

  19. Structural determinants of stereospecificity in yeast alcohol dehydrogenase.

    OpenAIRE

    Weinhold, E G; Glasfeld, A; Ellington, A D; Benner, S A

    1991-01-01

    Replacing Leu-182 by Ala in yeast alcohol dehydrogenase (YADH; alcohol:NAD+ oxidoreductase, EC 1.1.1.1) yields a mutant that retains 34% of its kcat value and makes one stereochemical "mistake" every 850,000 turnovers (instead of approximately 1 error every 7,000,000,000 turnovers in native YADH) in its selection of the 4-Re hydrogen of NADH. Half of the decrease in stereochemical fidelity comes from an increase in the rate of transfer of the 4-Si hydrogen of NADH. The mutant also accepts 5-m...

  20. Structures of citrate synthase and malate dehydrogenase of Mycobacterium tuberculosis.

    Science.gov (United States)

    Ferraris, Davide M; Spallek, Ralf; Oehlmann, Wulf; Singh, Mahavir; Rizzi, Menico

    2015-02-01

    The tricarboxylic acid (TCA) cycle is a central metabolic pathway of all aerobic organisms and is responsible for the synthesis of many important precursors and molecules. TCA cycle plays a key role in the metabolism of Mycobacterium tuberculosis and is involved in the adaptation process of the bacteria to the host immune response. We present here the first crystal structures of M. tuberculosis malate dehydrogenase and citrate synthase, two consecutive enzymes of the TCA, at 2.6 Å and 1.5 Å resolution, respectively. General analogies and local differences with the previously reported homologous protein structures are described.

  1. Lactate dehydrogenase assay for assessment of polycation cytotoxicity

    DEFF Research Database (Denmark)

    Parhamifar, Ladan; Andersen, Helene; Moghimi, Seyed Moien

    2013-01-01

    Cellular toxicity and/or cell death entail complex mechanisms that require detailed evaluation for proper characterization. A detailed mechanistic assessment of cytotoxicity is essential for design and construction of more effective polycations for nucleic acid delivery. A single toxicity assay...... cannot stand alone in determining the type and extent of damage or cell death mechanism. In this chapter we describe a lactate dehydrogenase (LDH) assay for high-throughput screening that can be used as a starting point for further detailed cytotoxicity determination. LDH release is considered an early...

  2. In vitro hydrogen production by glucose dehydrogenase and hydrogenase

    Energy Technology Data Exchange (ETDEWEB)

    Woodward, J. [Oak Ridge National Lab., TN (United States)

    1996-10-01

    A new in vitro enzymatic pathway for the generation of molecular hydrogen from glucose has been demonstrated. The reaction is based upon the oxidation of glucose by Thermoplasma acidophilum glucose dehydrogenase with the concomitant oxidation of NADPH by Pyrococcus furiosus hydrogenase. Stoichiometric yields of hydrogen were produced from glucose with continuous cofactor recycle. This simple system may provide a method for the biological production of hydrogen from renewable sources. In addition, the other product of this reaction, gluconic acid, is a high-value commodity chemical.

  3. Selective inhibition of 6-phosphogluconate dehydrogenase from Trypanosoma brucei

    Science.gov (United States)

    Bertelli, Massimo; El-Bastawissy, Eman; Knaggs, Michael H.; Barrett, Michael P.; Hanau, Stefania; Gilbert, Ian H.

    2001-05-01

    A number of triphenylmethane derivatives have been screened against 6-phosphogluconate dehydrogenase from Trypanosoma brucei and sheep liver. Some of these compounds show good inhibition of the enzymes and also selectivity towards the parasite enzyme. Modelling was undertaken to dock the compounds into the active sites of both enzymes. Using a combination of DOCK 3.5 and FLEXIDOCK a correlation was obtained between docking score and both activity for the enzymes and selectivity. Visualisation of the docked structures of the inhibitors in the active sites of the enzymes yielded a possible explanation of the selectivity for the parasite enzyme.

  4. Essential histidine residue in 3-ketosteroid-Δ1-dehydrogenase

    OpenAIRE

    Matsushita, Hiroyuki; Itagaki, Eiji; 板垣, 英治

    1992-01-01

    The variation with pH of kinetic parameters was examined for 3-ketosteroid-Δ1-dehydrogenase from Nocardia corallina. The V(max)/K(m) profile for 4-androstenedione indicates that activity is lost upon protonation of a cationic acid-type group with a pK value of 7.7. The enzyme was inactivated by diethylpyrocarbonate at pH 7.4 and the inactivation was substantially prevented by androstadienedione. Analyses of reactivation with neutral hydroxylamine, pH variation, and spectral changes of the ina...

  5. 11β-羟基类固醇脱氢酶2基因表达作为葡萄籽提取物预防乳腺癌靶点的探讨%Expression of 11 beta-hydroxysteroid dehydrogenase type 2 genes as a molecular target endpoint for the prevention of breast cell carcinogenesis with grape seed extracts

    Institute of Scientific and Technical Information of China (English)

    宋筱瑜; 王华骞

    2011-01-01

    Objective To study the change of 11 β-HSD 2 gene expression in carcinogenesis and cancer prevention and to study the possibility of using 11 β-HSD 2 gene expression as a molecular target endpoint in the progression of breast cell carcinogenesis suppressed by Grape Seed Extract (GSE). Methods Cell carcinogenesis model for human breast epithelial MCF10A cell was induced by treating the cell with carcinogens NNK and B[ a] P repeatedly, and the cell model system for the prevention of carcinogenesis was developed by combining GSE with NNK and B[ a] P. Western blot analysis was used to detect the expression of 11 β-HSD 2 gene. The biological change of carcinogen treated cells was studied by transfecting small interference RNA ( siRNA ) to inhibit 11 β-HSD 2 gene expression of cells. Results The colony formation of carcinogen treated cells in low-mitogen medium was less after the expression of 11 β-HSD 2 gene was inhibited by specific siRNA, which was just like the colony formation of normal cells. The expression of 11 β-HSD 2 gene was high in carcinogen treated cells, and the gene expression was low or undetectable in normal breast epithelial cells and cells combined treated with GSE and carcinogen. Conclusion The biological display of carcinogen treated cells could be normalized after the expression of 11 β-HSD 2 gene was inhibited. The mechanism for GSE preventing carcinogenesis might be the result of GSE inhibiting the expression of 11β-HSD 2 gene. 11β-HSD 2 gene might be the molecular target endpoint for the suppression of breast cell carcinogenesis by GSE.%目的 研究11β-羟基类固醇脱氢酶2型基因(11β-HSD 2)表达在癌症发生及预防过程中的变化,探讨该基因作为葡萄籽提取物(GSE)抑制乳腺上皮细胞慢性癌变过程中靶点的可能性.方法 建立低浓度致癌物NNK和B[a]P刺激乳腺上皮细胞MCF 10A癌变及GSE抑制乳腺上皮细胞癌变过程的细胞模型,研究瞬时转染了靶向11β-HSD 2基因的

  6. A highly efficient sorbitol dehydrogenase from Gluconobacter oxydans G624 and improvement of its stability through immobilization.

    Science.gov (United States)

    Kim, Tae-Su; Patel, Sanjay K S; Selvaraj, Chandrabose; Jung, Woo-Suk; Pan, Cheol-Ho; Kang, Yun Chan; Lee, Jung-Kul

    2016-09-16

    A sorbitol dehydrogenase (GoSLDH) from Gluconobacter oxydans G624 (G. oxydans G624) was expressed in Escherichia coli BL21(DE3)-CodonPlus RIL. The complete 1455-bp codon-optimized gene was amplified, expressed, and thoroughly characterized for the first time. GoSLDH exhibited Km and kcat values of 38.9 mM and 3820 s(-1) toward L-sorbitol, respectively. The enzyme exhibited high preference for NADP(+) (vs. only 2.5% relative activity with NAD(+)). GoSLDH sequencing, structure analyses, and biochemical studies, suggested that it belongs to the NADP(+)-dependent polyol-specific long-chain sorbitol dehydrogenase family. GoSLDH is the first fully characterized SLDH to date, and it is distinguished from other L-sorbose-producing enzymes by its high activity and substrate specificity. Isothermal titration calorimetry showed that the protein binds more strongly to D-sorbitol than other L-sorbose-producing enzymes, and substrate docking analysis confirmed a higher turnover rate. The high oxidation potential of GoSLDH for D-sorbitol was confirmed by cyclovoltametric analysis. Further, stability of GoSLDH significantly improved (up to 13.6-fold) after cross-linking of immobilized enzyme on silica nanoparticles and retained 62.8% residual activity after 10 cycles of reuse. Therefore, immobilized GoSLDH may be useful for L-sorbose production from D-sorbitol.

  7. A highly efficient sorbitol dehydrogenase from Gluconobacter oxydans G624 and improvement of its stability through immobilization

    Science.gov (United States)

    Kim, Tae-Su; Patel, Sanjay K. S.; Selvaraj, Chandrabose; Jung, Woo-Suk; Pan, Cheol-Ho; Kang, Yun Chan; Lee, Jung-Kul

    2016-01-01

    A sorbitol dehydrogenase (GoSLDH) from Gluconobacter oxydans G624 (G. oxydans G624) was expressed in Escherichia coli BL21(DE3)-CodonPlus RIL. The complete 1455-bp codon-optimized gene was amplified, expressed, and thoroughly characterized for the first time. GoSLDH exhibited Km and kcat values of 38.9 mM and 3820 s−1 toward L-sorbitol, respectively. The enzyme exhibited high preference for NADP+ (vs. only 2.5% relative activity with NAD+). GoSLDH sequencing, structure analyses, and biochemical studies, suggested that it belongs to the NADP+-dependent polyol-specific long-chain sorbitol dehydrogenase family. GoSLDH is the first fully characterized SLDH to date, and it is distinguished from other L-sorbose-producing enzymes by its high activity and substrate specificity. Isothermal titration calorimetry showed that the protein binds more strongly to D-sorbitol than other L-sorbose-producing enzymes, and substrate docking analysis confirmed a higher turnover rate. The high oxidation potential of GoSLDH for D-sorbitol was confirmed by cyclovoltametric analysis. Further, stability of GoSLDH significantly improved (up to 13.6-fold) after cross-linking of immobilized enzyme on silica nanoparticles and retained 62.8% residual activity after 10 cycles of reuse. Therefore, immobilized GoSLDH may be useful for L-sorbose production from D-sorbitol. PMID:27633501

  8. 小分子干扰RNA抑制高氧暴露下人肺腺癌A549细胞中的硫氧还蛋白-2对还原型烟酰胺腺嘌呤二核苷酸脱氢酶亚单位1、细胞色素C氧化酶工表达的影响%Suppressed expression of thioredoxin-2 by small interference RNA in A549 cells exposed to hyperoxia reduced expression of nicotinamide-adenine dinucleotide dehydrogenase subunit 1 and cytochrome C oxidase Ⅰ

    Institute of Scientific and Technical Information of China (English)

    蔡成; 常立文; 李文斌; 陈燕; 单瑞艳; 刘伟; 潘睿

    2010-01-01

    Objective To explore the effects of expression of thioredoxin-2(Trx-2) suppressed by small interference RNA(SiRNA) in A549 cells exposed to hyperoxia on expression of nicotinamide adenine dinucleotide(NADH) dehydrogenase subunit 1(ND1)and cytochrome C oxidase Ⅰ(COX Ⅰ). Methods A549 cells were gained by serial subcultivation in vitro and transfered with synthetic Trx-2 sequence-specific SiRNA and then were randomly divided into air group without interference,hyperoxia group without interference,air group after interference,and hyperoxia group after interference.After exposure to oxygen or room air for 12,24 and 48 h,expressions of Trx-2,ND1 and COX Ⅰ mRNA of these cells were detected by reverse transcription-polymerase chain reaction (RT-PCR),and Trx-2 protein was detected by Western blot. Results (1)Sequence-specific SiRNA targeting Trx-2 could significantly down-regulate its expression in A549 cells.(2)Trx-2 mRNA levds in hyperoxia group without interference at 24 h was higher than those in air group without interference(0.7799±0.1249 VS 0.4424±Ⅰ.1140,P<0.05).Th-2 mRNA levels in hyperoxia group after ireedcrence at 24 h and 48 h were 0.2774±0.0174 and 0.2587±0.0069,lower than those in air group after interference and hyperoxia group without interference (P<0.05).(3)ND1 mRNA levels in hyperoxia group without interference at 24 h was 0.6609±0.0368,lower than those in air group without interference(0.8898±0.1049)(P<0.05).ND1 mRNA levels in hyperoxia group after interference at 12 h was 0.8848±0.0135,higher than those in air group after imederence(P<0.05).ND1 mRNA levels in hypemxia group after interference at 48 h was 0.3808±0.0937,lower than those in air group after imerference and hyperoxia group without interference(P<0.05).(4)COXI mRNA levels in hypemxia group without inteference at 12,24 and 48 h were 1.7313±0.4331,2.1929±0.6722 and 2.0754±0.2584,higher than those in air group witheUt interference,respectively (P<0.05). Conclusions ND1 and

  9. Ethanol Metabolism by HeLa Cells Transduced with Human Alcohol Dehydrogenase Isoenzymes: Control of the Pathway by Acetaldehyde Concentration†

    Science.gov (United States)

    Matsumoto, Michinaga; Cyganek, Izabela; Sanghani, Paresh C.; Cho, Won Kyoo; Liangpunsakul, Suthat; Crabb, David W.

    2010-01-01

    Background Human class I alcohol dehydrogenase 2 isoenzymes (encoded by the ADH1B locus) have large differences in kinetic properties; however, individuals inheriting the alleles for the different isoenzymes exhibit only small differences in alcohol elimination rates. This suggests that other cellular factors must regulate the activity of the isoenzymes. Methods The activity of the isoenzymes expressed from ADH1B*1, ADH1B*2, and ADH1B*3 cDNAs was examined in stably transduced HeLa cell lines, including lines which expressed human low Km aldehyde dehydrogenase (ALDH2). The ability of the cells to metabolize ethanol was compared with that of HeLa cells expressing rat class I ADH (HeLa-rat ADH cells), rat hepatoma (H4IIEC3) cells, and rat hepatocytes. Results The isoenzymes had similar protein half-lives in the HeLa cells. Rat hepatocytes, H4IIEC3 cells, and HeLa-rat ADH cells oxidized ethanol much faster than the cells expressing the ADH1B isoenzymes. This was not explained by high cellular NADH levels or endogenous inhibitors; but rather because the activity of the β1 and β2 ADHs were constrained by the accumulation of acetaldehyde, as shown by the increased rate of ethanol oxidation by cell lines expressing β2 ADH plus ALDH2. Conclusion The activity of the human β2 ADH isoenzyme is sensitive to inhibition by acetaldehyde, which likely limits its activity in vivo. This study emphasizes the importance of maintaining a low steady–state acetaldehyde concentration in hepatocytes during ethanol metabolism. PMID:21166830

  10. Evolution of D-lactate dehydrogenase activity from glycerol dehydrogenase and its utility for D-lactate production from lignocellulose.

    Science.gov (United States)

    Wang, Qingzhao; Ingram, Lonnie O; Shanmugam, K T

    2011-11-22

    Lactic acid, an attractive, renewable chemical for production of biobased plastics (polylactic acid, PLA), is currently commercially produced from food-based sources of sugar. Pure optical isomers of lactate needed for PLA are typically produced by microbial fermentation of sugars at temperatures below 40 °C. Bacillus coagulans produces L(+)-lactate as a primary fermentation product and grows optimally at 50 °C and pH 5, conditions that are optimal for activity of commercial fungal cellulases. This strain was engineered to produce D(-)-lactate by deleting the native ldh (L-lactate dehydrogenase) and alsS (acetolactate synthase) genes to impede anaerobic growth, followed by growth-based selection to isolate suppressor mutants that restored growth. One of these, strain QZ19, produced about 90 g L(-1) of optically pure D(-)-lactic acid from glucose in < 48 h. The new source of D-lactate dehydrogenase (D-LDH) activity was identified as a mutated form of glycerol dehydrogenase (GlyDH; D121N and F245S) that was produced at high levels as a result of a third mutation (insertion sequence). Although the native GlyDH had no detectable activity with pyruvate, the mutated GlyDH had a D-LDH specific activity of 0.8 μmoles min(-1) (mg protein)(-1). By using QZ19 for simultaneous saccharification and fermentation of cellulose to D-lactate (50 °C and pH 5.0), the cellulase usage could be reduced to 1/3 that required for equivalent fermentations by mesophilic lactic acid bacteria. Together, the native B. coagulans and the QZ19 derivative can be used to produce either L(+) or D(-) optical isomers of lactic acid (respectively) at high titers and yields from nonfood carbohydrates.

  11. Glutamate dehydrogenase from pumpkin cotyledons: characterization and isoenzymes.

    Science.gov (United States)

    Chou, K H; Splittstoesser, W E

    1972-04-01

    Glutamate dehydrogenase from pumpkin (Cucurbita moschata Pior. cultivar Dickinson Field) cotyledons was found in both soluble and particulate fractions with the bulk of the activity in the soluble fraction. Both enzymes used NAD(H) and NADP(H) but NAD(H) was favored. The enzymes were classified as glutamate-NAD oxidoreductase, deaminating (EC 1.4.1.3). Both enzymes were heat stable, had a pH optimum for reductive amination of 8.0, and were inhibited by high concentrations of NH(4) (+) or alpha-ketoglutarate. The soluble enzyme was more sensitive to NH(4) (+) inhibition and was activated by metal ions after ammonium sulfate fractionation while the solubilized particulate enzyme was not. Inhibition by ethylenediaminetetraacetate was restored by several divalent ions and inhibition by p-hydroxymercuribenzoate was reversed by glutathione. Particulate glutamate dehydrogenase showed a greater activity with NADP. The molecular weights of the enzymes are 250,000. Separation of the enzymes by disc gel electrophoresis showed that during germination the soluble isoenzymes increased from 1 to 7 in number, while only one particulate isoenzyme was found at any time. This particulate isoenzyme was identical with one of the soluble isoenzymes. A number of methods indicated that the soluble isoenzymes were not simply removed from the particulate fraction and that true isoenzymes were found.

  12. Orthodontic Force Application in Correlation with Salivary Lactate Dehydrogenase Activity

    Directory of Open Access Journals (Sweden)

    Erik Husin

    2013-07-01

    Full Text Available Orthodontic tooth movement generate mechanical forces to periodontal ligament and alveolar bone. The forces correlate with initial responses of periodontal tissues and involving many metabolic changes. One of the metabolic changes detected in saliva is lactate dehydrogenase (LDH activity. Objectives: To evaluate the correlation between orthodontic interrupted force application, lactate dehydrogenase activity and the distance of tooth movement. Methods: upper premolar, pre-retraction of upper canine and 1, 7, 14, 21 and 28 days post-retraction of upper canine with 100g interrupted orthodontic force. Results: duration of force (F=11.926 p 14 and 28 days post-retraction of canine. The region of retraction correlated with the distance of tooth movement (F=7.377 p=0.007. The duration of force correlated with the distance of tooth movement (F=66.554 p=0.000. retraction of canine. Conclusion: This study concluded that orthodontic interrupted force application on canine could increase the distance of tooth movement and LDH activity in saliva.

  13. Toxicity of Nitrification Inhibitors on Dehydrogenase Activity in Soils

    Directory of Open Access Journals (Sweden)

    Ferisman Tindaon

    2011-01-01

    Full Text Available The objective of this research was to determine the effects of nitrification inhibitors (NIs such as 3,4-dimethylpyrazolephosphate=DMPP, 4-Chlor-methylpyrazole phosphate=ClMPP and dicyandiamide,DCD which might be expected to inhibit microbial activity, on dehydrogenase activity (DRA,in three different soils in laboratory conditions. Dehydrogenase activity were assessed via reduction of 2-p-Iodophenyl-3-p-nitrophenyl-5-phenyltetrazoliumchloride (INT. The toxicity and dose response curve of three NIs were quantified under laboratory conditions using a loamy clay, a sandy loam and a sandy soil. The quantitative determination of DHA was carried out spectrophotometrically. In all experiments, the influence of 5-1000 times the base concentration were examined. To evaluate the rate of inhibition with the increasing NI concentrations, dose reponse curves were presented and no observable effect level =NOEL, as well as effective dose ED10 and ED 50(10% and 50% inhibition were calculated. The NOEL for common microbial activity such as DHA was about 30–70 times higher than base concentration in all investigated soils. ClMPP exhibited the strongest influence on the non target microbial processes in the three soils if it compare to DMPP and DCD. The NOEL,ED10 and ED50 values higher in clay than in loamy or sandy soil. The NIs were generally most effective in sandy soils. The three NIs considered at the present state of knowledge as environmentally safe in use.

  14. Crystal structure of a chimaeric bacterial glutamate dehydrogenase

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Tânia; Sharkey, Michael A.; Engel, Paul C.; Khan, Amir R.

    2016-05-23

    Glutamate dehydrogenases (EC 1.4.1.2–4) catalyse the oxidative deamination of L-glutamate to α-ketoglutarate using NAD(P)+as a cofactor. The bacterial enzymes are hexameric, arranged with 32 symmetry, and each polypeptide consists of an N-terminal substrate-binding segment (domain I) followed by a C-terminal cofactor-binding segment (domain II). The catalytic reaction takes place in the cleft formed at the junction of the two domains. Distinct signature sequences in the nucleotide-binding domain have been linked to the binding of NAD+versusNADP+, but they are not unambiguous predictors of cofactor preference. In the absence of substrate, the two domains move apart as rigid bodies, as shown by the apo structure of glutamate dehydrogenase fromClostridium symbiosum. Here, the crystal structure of a chimaeric clostridial/Escherichia colienzyme has been determined in the apo state. The enzyme is fully functional and reveals possible determinants of interdomain flexibility at a hinge region following the pivot helix. The enzyme retains the preference for NADP+cofactor from the parentE. colidomain II, although there are subtle differences in catalytic activity.

  15. Structural analysis of fungus-derived FAD glucose dehydrogenase.

    Science.gov (United States)

    Yoshida, Hiromi; Sakai, Genki; Mori, Kazushige; Kojima, Katsuhiro; Kamitori, Shigehiro; Sode, Koji

    2015-08-27

    We report the first three-dimensional structure of fungus-derived glucose dehydrogenase using flavin adenine dinucleotide (FAD) as the cofactor. This is currently the most advanced and popular enzyme used in glucose sensor strips manufactured for glycemic control by diabetic patients. We prepared recombinant nonglycosylated FAD-dependent glucose dehydrogenase (FADGDH) derived from Aspergillus flavus (AfGDH) and obtained the X-ray structures of the binary complex of enzyme and reduced FAD at a resolution of 1.78 Å and the ternary complex with reduced FAD and D-glucono-1,5-lactone (LGC) at a resolution of 1.57 Å. The overall structure is similar to that of fungal glucose oxidases (GOxs) reported till date. The ternary complex with reduced FAD and LGC revealed the residues recognizing the substrate. His505 and His548 were subjected for site-directed mutagenesis studies, and these two residues were revealed to form the catalytic pair, as those conserved in GOxs. The absence of residues that recognize the sixth hydroxyl group of the glucose of AfGDH, and the presence of significant cavity around the active site may account for this enzyme activity toward xylose. The structural information will contribute to the further engineering of FADGDH for use in more reliable and economical biosensing technology for diabetes management.

  16. 大黄素对胰岛素抵抗大鼠脂肪组织11β-羟基类固醇脱氢酶1表达的影响%Effect of emodin on the expression of 11β-hydroxysteroid dehydrogenase type 1 in adipose tissue of insulin resistance rats

    Institute of Scientific and Technical Information of China (English)

    孙红爽; 乜春城; 朱小丽; 马红芳; 陈赫军; 种宝贵

    2016-01-01

    To observe the effect of emodin on the expression of 11β-HSD1 in adipose tissue of insulin resistance rats and investigate the possible mechanism,30 male Wistar rats were randomly divided into three groups:the control,model group and treatment group (n=10).The model was established by high fat diet feeding and dexamethasone stimulation.After 12 weeks,the treatment group was given emodin 200 mg.kg-1 by intragastric administration.After 4 weeks,insulin tolerance test was performed.Blood sugar,lipid,insulin and corticosterone level were measured.Liver index,visceral obesity index and HOMA-IR index were computed.The 11β-HSD1 gene and protein expression were measured.As results,compared to the model group,the insulin resistance was significantly improved in the treatment group,while blood glucose,insulin,lipid level,liver index and visceral obesity index were significantly decreased.Meanwhile,the expression of llβ-HSDI and protein in visceral adipose tissues was significantly decreased.In conclusion,emodin can significantly improve the insulin resistance in rats,which maybe related to the inhibition of the llβ-HSDI gene and protein expression.%观察大黄素对胰岛素抵抗大鼠脂肪组织11β-HSD1表达的影响,探讨其改善胰岛素抵抗的可能机制.采用30只雄性Wistar大鼠作为研究对象,随机分为对照组、模型组和给药组,每组10只.模型建立通过高脂饲料喂养结合地塞米松刺激的方式.12周后造模成功,给药组予大黄素200 mg.kg-1灌胃.给药4周后,进行胰岛素耐量试验,检测血糖、血脂、血液胰岛素及皮质酮水平,计算肝指数、内脏肥胖指数及HOMA-IR指数和11β-HSD1基因及蛋白表达情况.结果表明,与模型组比较,给药组胰岛素抵抗状态显著改善,血糖、胰岛素及血脂水平明显降低,肝指数及内脏肥胖指数也明显下降,同时内脏脂肪组织11β-HSD1基因及蛋白表达明显下调.可见大黄素可显著改善胰岛素抵

  17. Metabolic impact of an NADH-producing glucose-6-phosphate dehydrogenase in Escherichia coli

    DEFF Research Database (Denmark)

    Olavarria, K.; De Ingeniis, J.; Zielinski, D. C.

    2014-01-01

    PDH(R46E,Q47E). Through homologous recombination, the zwf loci (encoding G6PDH) in the chromosomes of WT and Δpgi E. coli strains were replaced by DNA encoding LmG6PDH(R46E,Q47E). Contrary to some predictions performed with flux balance analysis, the replacements caused a substantial effect......, we studied the metabolic response of this bacterium to the replacement of its glucose-6-phosphate dehydrogenase (G6PDH) by an NADH-producing variant. The homologous enzyme from Leuconostoc mesenteroides was studied by molecular dynamics and site-directed mutagenesis to obtain the NAD-preferring LmG6...... on the growth rates, increasing 59 % in the Δpgi strain, while falling 44 % in the WT. Quantitative PCR (qPCR) analysis of the zwf locus showed that the expression level of the mutant enzyme was similar to the native enzyme and the expression of genes encoding key enzymes of the central pathways also showed...

  18. Hyperinsulinism/hyperammonemia syndrome: insights into the regulatory role of glutamate dehydrogenase in ammonia metabolism.

    Science.gov (United States)

    Stanley, Charles A

    2004-04-01

    The second most common form of congenital hyperinsulinism, the hyperinsulinism/hyperammonemia syndrome (HI/HA), is associated with dominantly expressed missense mutations of the mitochondrial matrix enzyme, glutamate dehydrogenase (GDH). GDH catalyzes the oxidative deamination of glutamate to alpha-ketoglutarate plus ammonia, using NAD or NADP as co-factor. HI/HA mutations impair GDH sensitivity to its allosteric inhibitor, GTP, resulting in a gain of enzyme function and increased sensitivity to its allosteric activator, leucine. The phenotype is dominated by hypoglycemia with post-prandial hypoglycemia following protein meals, as well as fasting hypoglycemia. Plasma ammonia levels are increased 3-5 times normal due to expression of mutant GDH in liver, probably reflecting increased ammonia release from glutamate as well as impaired synthesis of NAG, due to reduction of hepatic glutamate pools. Ammonia levels are unaffected by feeding or fasting and appear to cause no symptoms, perhaps due to a protective effect of increased GDH activity in brain. The clinical consequences of the HI/HA mutations imply that GDH plays a central role in overall control of amino acid catabolism and ammonia metabolism integrating responses to changes in intracellular energy potential and amino acid levels.

  19. Cloning and characterization of a novel betaine aldehyde dehydrogenase gene from Suaeda corniculata.

    Science.gov (United States)

    Wang, F W; Wang, M L; Guo, C; Wang, N; Li, X W; Chen, H; Dong, Y Y; Chen, X F; Wang, Z M; Li, H Y

    2016-06-20

    Glycine betaine is an important quaternary ammonium compound that is produced in response to several abiotic stresses in many organisms. The synthesis of glycine betaine requires the catalysis of betaine aldehyde dehydrogenase (BADH), which can convert betaine aldehyde into glycine betaine in plants, especially in halotolerant plants. In this study, we isolated the full-length cDNA of BADH from Suaeda corniculata (ScBADH) using reverse transcriptase-polymerase chain reaction and rapid amplification of cDNA ends. Next, we analyzed the expression profile of ScBADH using real-time PCR. The results showed that ScBADH expression was induced in the roots, stems, and leaves of S. corniculata seedlings under salt and drought stress. Next, ScBADH was overexpressed in Arabidopsis, resulting in the transgenic plants exhibiting enhanced tolerance over wild-type plants under salt and drought stress. We then analyzed the levels of glycine betaine and proline, as well as superoxide dismutase (SOD) activity, during salt stress in WT and transgenic Arabidopsis. The results indicated that overexpression of ScBADH produced more glycine betaine and proline, and increased SOD activity under NaCl treatment. Our results suggest that ScBADH might be a positive regulator in plants during the response to NaCl.

  20. Cloning of Lactate dehydrogenase Gene and Effect on the Waterlogging Tolerance of Brassica napus L.

    Directory of Open Access Journals (Sweden)

    Ben-bo Xu

    2012-10-01

    Full Text Available To investigate the mechanism on waterlogging tolerance in Brassica napus, 12 B. napus cultivars with different waterlogging tolerance were used in the research and Waterlogging Tolerance Index (WTI was calculated by multiplying relative percentage germination and the relative seedling height. The results indicated that Lactate Dehydrogenase (LDH enzyme activity rapidly increased at 24 h after waterlogging treatment and reached peak between 48-72 h. WTI was correlated with LDH enzyme activity at 24 h after water logging treatment and the correlation coefficient between them was 0.84. Transcription level of the BnLDH had significant difference in the 12 lines after waterlogging treatment. BnLDH expression level was very low before waterlogging treatment and induced by waterlogging treatment and arrived at peak at 48 h. Correlation analysis indicated correlation coefficient between WTI and BnLDH expression at 24 and 48 h after waterlogging treatment was 0.56 and 0.72, respectively. An LDH gene, denoted BnLDH-1, was cloned from oilseeds by the Rapid Amplification of CDNA Ends (RACE from 12 materials and the results indicated all of them had same protein sequence.

  1. Cellular thiamine status is coupled to function of mitochondrial 2-oxoglutarate dehydrogenase.

    Science.gov (United States)

    Mkrtchyan, G; Graf, A; Bettendorff, L; Bunik, V

    2016-12-01

    Decreased thiamine and reduced activity of thiamine diphosphate (ThDP)-dependent 2-oxoglutarate dehydrogenase (OGDH) cause neurodegeneration. We hypothesized on concerted cell-specific regulation of the thiamine metabolism and ThDP-dependent reactions. We identified a smaller thiamine pool, a lower expression of the mitochondrial ThDP transporter, and a higher expression of OGDH in rat astrocytes versus neuroblastoma N2A. According to the data, the astrocytic OGDH may be up-regulated by an increase in intracellular ThDP, while the neuroblastomal OGDH functions at full ThDP saturation. Indeed, in rat astrocytes and brain cortex, OGDH inhibition by succinyl phosphonate (SP) enlarged the pool of thiamine compounds. Increased ThDP level in response to the OGDH inhibition presumably up-regulated the enzyme to compensate for a decrease in reducing power which occurred in SP-treated astrocytes. Under the same SP treatment of N2A cells, their thiamine pool and reducing power were unchanged, although SP action was evident from accumulation of glutamate. The presented data indicate that functional interplay between OGDH, other proteins of the tricarbocylic acid cycle and proteins of thiamine metabolism is an important determinant of physiology-specific networks and their homeostatic mechanisms.

  2. 11 beta-hydroxysteroid dehydrogenase type 1 promotes differentiation of 3T3-L1 preadipocyte

    Institute of Scientific and Technical Information of China (English)

    Yun LIU; Yan SUN; Ting ZHU; Yu XIE; Jing YU; Wen-lan SUN; Guo-xian DING; Gang HU

    2007-01-01

    Aim: To investigate the relationship between 11 beta-hydroxysteroid dehydroge-nase type 1 (1 lbeta-HSD1), a potential link between obesity and type 2 diabetes,and preadipocyte differentiation. Methods: Mouse 11beta-HSD1 siRNA plasmids were transfected into 3T3-L1 preadipocytes (a cell line derived from mouse Swiss3T3 cells that were isolated from mouse embryo), for examination of the effect of targeted 11 beta-HSD1 inhibition on differentiation of 3T3-L1 cells. Dif-ferentiation was stimulated with 3-isobutyl-1-methyxanthine, insulin, and dexamethasone. The transcription level of the genes was detected by real-time PCR. Results: Lipid accumulation was significantly inhibited in cells transfected with mouse 11beta-HSD1 siRNA compared with non-transfected 3T3-L1 cells.Fewer lipid droplets were detected in the transfected cells both prior to stimulation and after stimulation with differentiation-inducing reagents. The expression of adipocyte differentiation-associated markers such as lipoprotein lipase and fatty acid synthetase were downregulated in the transfected cells. Similarly, the expres-sion of preadipocyte factor-1, an inhibitor of adipocyte differentiation, was downregulated upon stimulation of differentiation and had no changes in the transfected cells. Conclusion: 11 beta-HSD1 can promote preadipocyte differentiation. Based on this, we propose that 11 beta-HSD1 may be an important candidate mediator of obesity and obesity-induced insulin resistance.

  3. Molecular evidence of sorbitol dehydrogenase in tomato, a non-Rosaceae plant.

    Science.gov (United States)

    Ohta, Kazuhiro; Moriguchi, Ryo; Kanahama, Koki; Yamaki, Shohei; Kanayama, Yoshinori

    2005-12-01

    The enzyme NAD-dependent sorbitol dehydrogenase (SDH) is well characterized in the Rosaceae family of fruit trees, which synthesizes sorbitol as a translocatable photosynthate. Expressed sequence tags of SDH-like sequences have also been generated from various non-Rosaceae species that do not synthesize sorbitol as a primary photosynthetic product, but the physiological roles of the encoded proteins in non-Rosaceae plants are unknown. Therefore, we isolated an SDH-like cDNA (SDL) from tomato (Lycopersicon esculentum Mill.). Genomic Southern blot analysis suggested that SDL exists in the tomato genome as a single-copy gene. Northern blot analysis showed that SDL is ubiquitously expressed in tomato plants. Recombinant SDL protein was produced and purified for enzymatic characterization. SDL catalyzed the interconversion of sorbitol and fructose with NAD (H). SDL showed highest activity for sorbitol among the several substrates tested. SDL showed no activity with NADP+. Thus, SDL was identified as a SDH, although the Km values and substrate specificity of SDL were significantly different from those of SDH purified from the Japanese pear (Pyrus pyrifolia), a Rosaceae fruit tree. In addition, tomato was transformed with antisense SDL to evaluate the contribution of SDL to SDH activity in tomato. The transformation decreased SDH activity to approximately 50% on average. Taken together, these results provide molecular evidence of SDH in tomato, and SDL was renamed LeSDH.

  4. Ubiquitous distribution and different subcellular localization of sorbitol dehydrogenase in fruit and leaf of apple.

    Science.gov (United States)

    Wang, Xiu-Ling; Xu, Yan-Hong; Peng, Chang-Cao; Fan, Ren-Chun; Gao, Xin-Qi

    2009-01-01

    NAD(+)-dependent sorbitol dehydrogenase (NAD-SDH, EC 1.1.1.14), a key enzyme in sorbitol metabolism, plays an important role in regulating sink strength and determining the quality of apple fruit. Understanding the tissue and subcellular localization of NAD-SDH is helpful for understanding sorbitol metabolism in the apple. In this study, two NAD-SDH cDNA sequences were isolated from apple fruits (Malus domestica Borkh cv. Starkrimson) and named MdSDH5 and MdSDH6. Immunohistochemical analysis revealed that NAD-SDH is distributed in both the flesh and the vascular tissue of the fruit, and the vascular tissue and mesophyll tissue in the young and old leaves, indicating that it is a ubiquitous protein expressed in both sink and source organs. Immunogold electron microscopy analysis demonstrated that NAD-SDH is localized mainly in the cytoplasm and chloroplast of the fruit and leaves. The chloroplast localization of NAD-SDH was confirmed by the transient expression of MdSDH5-GFP and MdSDH6-GFP in the mesophyll protoplast of Arabidopsis. NAD-SDH was also found in electron opaque deposits of vacuoles in young and mature leaves. These data show that NAD-SDH has different subcellular localizations in fruit and leaves, indicating that it might play a different role in sorbitol metabolism in different tissues of apple.

  5. Alcohol dehydrogenase and aldehyde dehydrogenase gene polymorphisms, alcohol intake and the risk of colorectal cancer in the European Prospective Investigation into Cancer and Nutrition study

    DEFF Research Database (Denmark)

    Ferrari, P.; McKay, J. D.; Jenab, M.

    2012-01-01

    BACKGROUND/OBJECTIVES: Heavy alcohol drinking is a risk factor of colorectal cancer (CRC), but little is known on the effect of polymorphisms in the alcohol-metabolizing enzymes, alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) on the alcohol-related risk of CRC in Caucasian populati......BACKGROUND/OBJECTIVES: Heavy alcohol drinking is a risk factor of colorectal cancer (CRC), but little is known on the effect of polymorphisms in the alcohol-metabolizing enzymes, alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) on the alcohol-related risk of CRC in Caucasian...... populations.SUBJECTS/METHODS: A nested case-control study (1269 cases matched to 2107controls by sex, age, study centre and date of blood collection) was conducted within the European Prospective Investigation into Cancer and Nutrition (EPIC) to evaluate the impact of rs1229984 (ADH1B), rs1573496 (ADH7...

  6. Phosphoglycerate dehydrogenase is a novel predictor for poor prognosis in gastric cancer

    Directory of Open Access Journals (Sweden)

    Xian Y

    2016-09-01

    Full Text Available Yun Xian,1,* Shu Zhang,2,* Xudong Wang,3 Jin Qin,2 Wei Wang,2 Han Wu4 1School of Public Health, Nantong University, 2Department of Pathology, 3Department of Laboratory Medicine, 4Department of General Surgery, Affiliated Hospital of Nantong University, Nantong, Jiangsu, People’s Republic of China *These authors contributed equally to this work Purpose: Phosphoglycerate dehydrogenase (PHGDH acts as a key metabolic enzyme in the rate-limiting step in serine biosynthesis and plays an important role in metastasis of several cancers. The aim of this study was to investigate the prognostic value of PHGDH in gastric cancer (GC. Methods: The messenger RNA expression of PHGDH was determined in 20 pairs of cancerous and adjacent nontumor tissues by real-time polymerase chain reaction. Immunohistochemistry of PHGDH was performed on tissue microarray, composed of 482 GC and 64 matched adjacent nontumor tissues acquired from surgery, 20 chronic gastritis, 18 intestinal metaplasia, and 31 low-grade and 66 high-grade intraepithelial neoplasias acquired through gastric endoscopic biopsy. Univariate and multivariate Cox proportional hazard models were used to perform survival analyses. Results: Both PHGDH messenger RNA and protein product exhibited GC tissue-preferred expression, when compared with benign tissues. The high PHGDH expression was significantly correlated with histological type (P=0.011, tumor stage (P=0.014, and preoperative carcinoembryonic antigen (P<0.001. A negative correlation was found between PHGDH expression and the 5-year survival rate of patients with GC. Furthermore, multivariate analysis indicated that PHGDH was an independent prognostic factor for outcome in GC. Conclusion: PHGDH is important in predicting patient outcomes and is a potential target for the development of therapeutic approaches to GC. Keywords: metabolism, gastric cancer, prognosis, serine biosynthesis

  7. 11β-hydroxysteroid dehydrogenase enzymes modulate effects of glucocorticoids in rheumatoid arthritis synovial cells.

    Science.gov (United States)

    Schmidt, Martin; Straub, Rainer H

    2015-01-01

    The tissue availability of active glucocorticoids (cortisol in humans) depends on their rate of synthesis from cholesterol, downstream metabolism, excretion and interconversion. The latter is mediated by the 11β-hydroxysteroid dehydrogenases (11βHSDs). In this review, we summarize the features of the two isoenzymes, 11βHSD1 and 11βHSD2, and current available experimental data related to 11βHSDs, which are relevant in the context of synovial cells in rheumatoid arthritis (RA). We conclude that due to complex feedback mechanisms inherent to the hypothalamic-pituitary-adrenal axis, currently available transgenic animal models cannot display the full potential otherwise inherent to the techniques. Studies with tissue explants, mixed synovial cell preparations, cell lines derived from synovial cells, and related primary cells or established cell lines indicate that there are relatively clear differences between the two isoenzymes. 11βHSD1 is expressed primarily in fibroblasts and osteoblasts, and may be responsible for fibroblast survival and aid in the resolution of inflammation, but it is also involved in bone damage. 11βHSD2 is expressed primarily in macrophages and lymphocytes, and may be responsible for their survival, suggesting that it is critical in chronic inflammation. The situation in synovial tissue would allow 11βHSD2-expressing cells to tap the energy resources of 11βHSD1-expressing cells. The overall properties of this local glucocorticoid interconversion system might limit therapeutic use of glucocorticoids in RA. © 2014 S. Karger AG, Basel.

  8. The diagnostic value of alcohol dehydrogenase (ADH) isoenzymes and aldehyde dehydrogenase (ALDH) measurement in the sera of gastric cancer patients.

    Science.gov (United States)

    Jelski, Wojciech; Orywal, Karolina; Laniewska, Magdalena; Szmitkowski, Maciej

    2010-12-01

    Alcohol dehydrogenase (ADH) and aldehyde dehydrogenase (ALDH) are present in gastric cancer cells (GC). Moreover, the activity of total ADH and class IV isoenzymes is significantly higher in cancer tissue than in healthy mucosa. The activity of these enzymes in cancer cells is probably reflected in the sera and could thus be helpful for diagnostics of gastric cancer. The aim of this study was to investigate a potential role of ADH and ALDH as tumor markers for gastric cancer. We defined diagnostic sensitivity, specificity, predictive value for positive and negative results, and receiver-operating characteristics (ROC) curve for tested enzymes. Serum samples were taken from 168 patients with gastric cancer before treatment and from 168 control subjects. Total ADH activity and class III and IV isoenzymes were measured by photometric but ALDH activity and ADH I and II by the fluorometric method, with class-specific fluorogenic substrates. There was significant increase in the activity of ADH IV isoenzyme and ADH total in the sera of gastric cancer patients compared to the control. The diagnostic sensitivity for ADH IV was 73%, specificity 79%, positive and negative predictive values were 81 and 72% respectively. Area under ROC curve for ADH IV was 0.67. The results suggest a potential role for ADH IV as marker of gastric cancer.

  9. Structural basis for the dysfunctioning of human 2-oxo acid dehydrogenase complexes

    NARCIS (Netherlands)

    Hengeveld, A.F.; Kok, de A.

    2002-01-01

    2-oxo acid dehydrogenase complexes are a ubiquitous family of multienzyme systems that catalyse the oxidative decarboxylation of various 2-oxo acid substrates. They play a key role in the primary energy metabolism: in glycolysis (pyruvate dehydrogenase complex), the citric acid cycle (2-oxoglutarate

  10. Role of phosphoenolpyruvate in the NADP-isocitrate dehydrogenase and isocitrate lyase reaction in Escherichia coli.

    Science.gov (United States)

    Ogawa, Tadashi; Murakami, Keiko; Mori, Hirotada; Ishii, Nobuyoshi; Tomita, Masaru; Yoshin, Masataka

    2007-02-01

    Phosphoenolpyruvate inhibited Escherichia coli NADP-isocitrate dehydrogenase allosterically (Ki of 0.31 mM) and isocitrate lyase uncompetitively (Ki' of 0.893 mM). Phosphoenolpyruvate enhances the uncompetitive inhibition of isocitrate lyase by increasing isocitrate, which protects isocitrate dehydrogenase from the inhibition, and contributes to the control through the tricarboxylic acid cycle and glyoxylate shunt.

  11. Role of Phosphoenolpyruvate in the NADP-Isocitrate Dehydrogenase and Isocitrate Lyase Reaction in Escherichia coli▿

    OpenAIRE

    2006-01-01

    Phosphoenolpyruvate inhibited Escherichia coli NADP-isocitrate dehydrogenase allosterically (Ki of 0.31 mM) and isocitrate lyase uncompetitively (Ki′ of 0.893 mM). Phosphoenolpyruvate enhances the uncompetitive inhibition of isocitrate lyase by increasing isocitrate, which protects isocitrate dehydrogenase from the inhibition, and contributes to the control through the tricarboxylic acid cycle and glyoxylate shunt.

  12. P450BM3 fused to phosphite dehydrogenase allows phosphite-driven selective oxidations

    NARCIS (Netherlands)

    Beyer, Nina; Kulig, Justyna K; Bartsch, Anette; Hayes, Martin A; Janssen, Dick B; Fraaije, Marco W

    2016-01-01

    To facilitate the wider application of the NADPH-dependent P450BM3, we fused the monooxygenase with a phosphite dehydrogenase (PTDH). The resulting monooxygenase-dehydrogenase fusion enzyme acts as a self-sufficient bifunctional catalyst, accepting phosphite as a cheap electron donor for the regener

  13. Sorbitol production from lactose by engineered Lactobacillus casei deficient in sorbitol transport system and mannitol-1-phosphate dehydrogenase.

    Science.gov (United States)

    De Boeck, Reinout; Sarmiento-Rubiano, Luz Adriana; Nadal, Inmaculada; Monedero, Vicente; Pérez-Martínez, Gaspar; Yebra, María J

    2010-02-01

    Sorbitol is a sugar alcohol largely used in the food industry as a low-calorie sweetener. We have previously described a sorbitol-producing Lactobacillus casei (strain BL232) in which the gutF gene, encoding a sorbitol-6-phosphate dehydrogenase, was expressed from the lactose operon. Here, a complete deletion of the ldh1 gene, encoding the main L-lactate dehydrogenase, was performed in strain BL232. In a resting cell system with glucose, the new strain, named BL251, accumulated sorbitol in the medium that was rapidly metabolized after glucose exhaustion. Reutilization of produced sorbitol was prevented by deleting the gutB gene of the phosphoenolpyruvate: sorbitol phosphotransferase system (PTS(Gut)) in BL251. These results showed that the PTS(Gut) did not mediate sorbitol excretion from the cells, but it was responsible for uptake and reutilization of the synthesized sorbitol. A further improvement in sorbitol production was achieved by inactivation of the mtlD gene, encoding a mannitol-1-phosphate dehydrogenase. The new strain BL300 (lac::gutF Deltaldh1 DeltagutB mtlD) showed an increase in sorbitol production whereas no mannitol synthesis was detected, avoiding thus a polyol mixture. This strain was able to convert lactose, the main sugar from milk, into sorbitol, either using a resting cell system or in growing cells under pH control. A conversion rate of 9.4% of lactose into sorbitol was obtained using an optimized fed-batch system and whey permeate, a waste product of the dairy industry, as substrate.

  14. Pyruvate Kinase M2 and Lactate Dehydrogenase A Are Overexpressed in Pancreatic Cancer and Correlate with Poor Outcome.

    Science.gov (United States)

    Mohammad, Goran Hamid; Olde Damink, S W M; Malago, Massimo; Dhar, Dipok Kumar; Pereira, Stephen P

    2016-01-01

    Pancreatic cancer has a 5-year survival rate of less than 4%. Despite advances in diagnostic technology, pancreatic cancer continues to be diagnosed at a late and incurable stage. Accurate biomarkers for early diagnosis and to predict treatment response are urgently needed. Since alteration of glucose metabolism is one of the hallmarks of cancer cells, we proposed that pyruvate kinase type M2 (M2PK) and lactate dehydrogenase A (LDHA) enzymes could represent novel diagnostic markers and potential therapeutic targets in pancreatic cancer. In 266 tissue sections from normal pancreas, pancreatic cystic neoplasms, pancreatic intraepithelial neoplasia (PanIN) and cancer, we evaluated the expression of PKM2, LDHA, Ki-67 and CD8+ by immunohistochemistry and correlated these markers with clinicopathological characteristics and patient survival. PKM2 and LDHA expression was also assessed by Western blot in 10 human pancreatic cancer cell lines. PKM2 expression increased progressively from cyst through PanIN to cancer, whereas LDHA was overexpressed throughout the carcinogenic process. All but one cell line showed high expression of both proteins. Patients with strong PKM2 and LDHA expression had significantly worse survival than those with weak PKM2 and/or LDHA expression (7.0 months vs. 27.9 months, respectively, p = 0.003, log rank test). The expression of both PKM2 and LDHA correlated directly with Ki-67 expression, and inversely with intratumoral CD8+ cell count. PKM2 was significantly overexpressed in poorly differentiated tumours and both PKM2 and LDHA were overexpressed in larger tumours. Multivariable analysis showed that combined expression of PKM2 and LDHA was an independent poor prognostic marker for survival. In conclusion, our results demonstrate a high expression pattern of two major glycolytic enzymes during pancreatic carcinogenesis, with increased expression in aggressive tumours and a significant adverse effect on survival.

  15. Pyruvate Kinase M2 and Lactate Dehydrogenase A Are Overexpressed in Pancreatic Cancer and Correlate with Poor Outcome.

    Directory of Open Access Journals (Sweden)

    Goran Hamid Mohammad

    Full Text Available Pancreatic cancer has a 5-year survival rate of less than 4%. Despite advances in diagnostic technology, pancreatic cancer continues to be diagnosed at a late and incurable stage. Accurate biomarkers for early diagnosis and to predict treatment response are urgently needed. Since alteration of glucose metabolism is one of the hallmarks of cancer cells, we proposed that pyruvate kinase type M2 (M2PK and lactate dehydrogenase A (LDHA enzymes could represent novel diagnostic markers and potential therapeutic targets in pancreatic cancer. In 266 tissue sections from normal pancreas, pancreatic cystic neoplasms, pancreatic intraepithelial neoplasia (PanIN and cancer, we evaluated the expression of PKM2, LDHA, Ki-67 and CD8+ by immunohistochemistry and correlated these markers with clinicopathological characteristics and patient survival. PKM2 and LDHA expression was also assessed by Western blot in 10 human pancreatic cancer cell lines. PKM2 expression increased progressively from cyst through PanIN to cancer, whereas LDHA was overexpressed throughout the carcinogenic process. All but one cell line showed high expression of both proteins. Patients with strong PKM2 and LDHA expression had significantly worse survival than those with weak PKM2 and/or LDHA expression (7.0 months vs. 27.9 months, respectively, p = 0.003, log rank test. The expression of both PKM2 and LDHA correlated directly with Ki-67 expression, and inversely with intratumoral CD8+ cell count. PKM2 was significantly overexpressed in poorly differentiated tumours and both PKM2 and LDHA were overexpressed in larger tumours. Multivariable analysis showed that combined expression of PKM2 and LDHA was an independent poor prognostic marker for survival. In conclusion, our results demonstrate a high expression pattern of two major glycolytic enzymes during pancreatic carcinogenesis, with increased expression in aggressive tumours and a significant adverse effect on survival.

  16. Krebs cycle metabolite profiling for identification and stratification of pheochromocytomas/paragangliomas due to succinate dehydrogenase deficiency

    NARCIS (Netherlands)

    Richter, S; Peitzsch, M.; Rapizzi, E.; Lenders, J.W.M.; Qin, N.; Cubas, A.A. de; Schiavi, F.; Rao, J.U.; Beuschlein, F.; Quinkler, M.; Timmers, H.J.L.M.; Opocher, G.; Mannelli, M.; Pacak, K.; Robledo, M.; Eisenhofer, G.

    2014-01-01

    CONTEXT: Mutations of succinate dehydrogenase A/B/C/D genes (SDHx) increase susceptibility to development of pheochromocytomas and paragangliomas (PPGLs), with particularly high rates of malignancy associated with SDHB mutations. OBJECTIVE: We assessed whether altered succinate dehydrogenase product

  17. Identification and Overexpression of a Bifunctional Aldehyde/Alcohol Dehydrogenase Responsible for Ethanol Production in Thermoanaerobacter mathranii

    DEFF Research Database (Denmark)

    Yao, Shuo; Just Mikkelsen, Marie

    2010-01-01

    Thermoanaerobacter mathranii contains four genes, adhA, adhB, bdhA and adhE, predicted to code for alcohol dehydrogenases involved in ethanol metabolism. These alcohol dehydrogenases were characterized as NADP(H)-dependent primary alcohol dehydrogenase (AdhA), secondary alcohol dehydrogenase (Adh......B), butanol dehydrogenase (BdhA) and NAD(H)-dependent bifunctional aldehyde/alcohol dehydrogenase (AdhE), respectively. Here we observed that AdhE is an important enzyme responsible for ethanol production in T. mathranii based on the constructed adh knockout strains. An adhE knockout strain fails to produce...... ethanol as a fermentation product, while other adh knockout strains showed no significant difference from the wild type. Further analysis revealed that the ΔadhE strain was defective in aldehyde dehydrogenase activity, but still maintained alcohol dehydrogenase activity. This showed that AdhE is the major...

  18. The reaction of choline dehydrogenase with some electron acceptors.

    Science.gov (United States)

    Barrett, M C; Dawson, A P

    1975-12-01

    1. The choline dehydrogenase (EC 1.1.99.1) WAS SOLUBILIZED FROM ACETONE-DRIED POWDERS OF RAT LIVER MITOCHONDRIA BY TREATMENT WITH Naja naja venom. 2. The kinetics of the reaction of enzyme with phenazine methosulphate and ubiquinone-2 as electron acceptors were investigated. 3. With both electron acceptors the reaction mechanism appears to involve a free, modified-enzyme intermediate. 4. With some electron acceptors the maximum velocity of the reaction is independent of the nature of the acceptor. With phenazine methosulphate and ubiquinone-2 as acceptors the Km value for choline is also independent of the nature of the acceptor molecule. 5. The mechanism of the Triton X-100-solubilized enzyme is apparently the smae as that for the snake venom solubilized enzyme.

  19. Pyruvate dehydrogenase complex in cerebral ischemia-reperfusion injury

    Directory of Open Access Journals (Sweden)

    Alexa Thibodeau

    2016-01-01

    Full Text Available Pyruvate dehydrogenase (PDH complex is a mitochondrial matrix enzyme that serves a critical role in the conversion of anaerobic to aerobic cerebral energy. The regulatory complexity of PDH, coupled with its significant influence in brain metabolism, underscores its susceptibility to, and significance in, ischemia-reperfusion injury. Here, we evaluate proposed mechanisms of PDH-mediated neurodysfunction in stroke, including oxidative stress, altered regulatory enzymatic control, and loss of PDH activity. We also describe the neuroprotective influence of antioxidants, dichloroacetate, acetyl-L-carnitine, and combined therapy with ethanol and normobaric oxygen, explained in relation to PDH modulation. Our review highlights the significance of PDH impairment in stroke injury through an understanding of the mechanisms by which it is modulated, as well as an exploration of neuroprotective strategies available to limit its impairment.

  20. Fabricating polystyrene fiber-dehydrogenase assemble as a functional biocatalyst.

    Science.gov (United States)

    An, Hongjie; Jin, Bo; Dai, Sheng

    2015-01-01

    Immobilization of the enzymes on nano-structured materials is a promising approach to enhance enzyme stabilization, activation and reusability. This study aimed to develop polystyrene fiber-enzyme assembles to catalyze model formaldehyde to methanol dehydrogenation reaction, which is an essential step for bioconversion of CO2 to a renewable bioenergy. We fabricated and modified electrospun polystyrene fibers, which showed high capability to immobilize dehydrogenase for the fiber-enzyme assembles. Results from evaluation of biochemical activities of the fiber-enzyme assemble showed that nitriation with the nitric/sulfuric acid ratio (v/v, 10:1) and silanization treatment delivered desirable enzyme activity and long-term storage stability, showing great promising toward future large-scale applications.

  1. Benzaldehyde dehydrogenase from chitosan-treated Sorbus aucuparia cell cultures.

    Science.gov (United States)

    Gaid, Mariam M; Sircar, Debabrata; Beuerle, Till; Mitra, Adinpunya; Beerhues, Ludger

    2009-09-01

    Cell cultures of Sorbus aucuparia respond to the addition of chitosan with the accumulation of the biphenyl phytoalexin aucuparin. The carbon skeleton of this inducible defense compound is formed by biphenyl synthase (BIS) from benzoyl-CoA and three molecules of malonyl-CoA. The formation of benzoyl-CoA proceeds via benzaldehyde as an intermediate. Benzaldehyde dehydrogenase (BD), which converts benzaldehyde into benzoic acid, was detected in cell-free extracts from S. aucuparia cell cultures. BD and BIS were induced by chitosan treatment. The preferred substrate for BD was benzaldehyde (K(m)=49 microM). Cinnamaldehyde and various hydroxybenzaldehydes were relatively poor substrates. BD activity was strictly dependent on the presence of NAD(+) as a cofactor (K(m)=67 microM).

  2. Glucose-6 phosphate dehydrogenase deficiency and psychotic illness

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    Vijender Singh

    2012-01-01

    Full Text Available Mr. T, a 28-year-old unmarried male, a diagnosed case of Glucose-6 Phosphate Dehydrogenase (G6PD deficiency since childhood, presented with 13 years of psychotic illness and disturbed biological functions. He showed poor response to antipsychotics and mood stabilizers and had three prior admissions to Psychiatry. There was a family history of psychotic illness. The General Physical Examination and Systemic Examination were unremarkable. Mental Status Examination revealed increased psychomotor activity, pressure of speech, euphoric affect, prolixity, delusion of persecution, delusion of grandiosity, delusion of control, thought withdrawal and thought insertion, and second and third person auditory hallucinations, with impaired judgment and insight. A diagnosis of schizophrenia paranoid type, with a differential diagnosis of schizoaffective disorder manic subtype, was made. This case is being reported for its rarity and atypicality of clinical presentation, as well as a course of psychotic illness in the G6PD Deficiency state,with its implications on management.

  3. IMP Dehydrogenase: Structural Schizophrenia and an Unusual Base

    Energy Technology Data Exchange (ETDEWEB)

    Hedstrom,L.; Gan, L.

    2006-01-01

    Textbooks describe enzymes as relatively rigid templates for the transition state of a chemical reaction, and indeed an enzyme such as chymotrypsin, which catalyzes a relatively simple hydrolysis reaction, is reasonably well described by this model. Inosine monophosphate dehydrogenase (IMPDH) undergoes a remarkable array of conformational transitions in the course of a complicated catalytic cycle, offering a dramatic counterexample to this view. IMPDH displays several other unusual mechanistic features, including an Arg residue that may act as a general base catalyst and a dynamic monovalent cation site. Further, IMPDH appears to be involved in 'moon-lighting' functions that may require additional conformational states. How the balance between conformational states is maintained and how the various conformational states interconvert is only beginning to be understood.

  4. Microbial metabolic activity in soil as measured by dehydrogenase determinations

    Science.gov (United States)

    Casida, L. E., Jr.

    1977-01-01

    The dehydrogenase technique for measuring the metabolic activity of microorganisms in soil was modified to use a 6-h, 37 C incubation with either glucose or yeast extract as the electron-donating substrate. The rate of formazan production remained constant during this time interval, and cellular multiplication apparently did not occur. The technique was used to follow changes in the overall metabolic activities of microorganisms in soil undergoing incubation with a limiting concentration of added nutrient. The sequence of events was similar to that obtained by using the Warburg respirometer to measure O2 consumption. However, the major peaks of activity occurred earlier with the respirometer. This possibly is due to the lack of atmospheric CO2 during the O2 consumption measurements.

  5. Encapsulation of Alcohol Dehydrogenase in Mannitol by Spray Drying

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    Hirokazu Shiga

    2014-03-01

    Full Text Available The retention of the enzyme activity of alcohol dehydrogenase (ADH has been studied in various drying processes such as spray drying. The aim of this study is to encapsulate ADH in mannitol, either with or without additive in order to limit the thermal denaturation of the enzyme during the drying process. The retention of ADH activity was investigated at different drying temperatures. When mannitol was used, the encapsulated ADH was found inactive in all the dried powders. This is presumably due to the quick crystallization of mannitol during spray drying that resulted in the impairment of enzyme protection ability in comparison to its amorphous form. Maltodextin (dextrose equivalent = 11 was used to reduce the crystallization of mannitol. The addition of maltodextrin increased ADH activity and drastically changed the powder X-ray diffractogram of the spray-dried powders.

  6. Encapsulation of alcohol dehydrogenase in mannitol by spray drying.

    Science.gov (United States)

    Shiga, Hirokazu; Joreau, Hiromi; Neoh, Tze Loon; Furuta, Takeshi; Yoshii, Hidefumi

    2014-03-24

    The retention of the enzyme activity of alcohol dehydrogenase (ADH) has been studied in various drying processes such as spray drying. The aim of this study is to encapsulate ADH in mannitol, either with or without additive in order to limit the thermal denaturation of the enzyme during the drying process. The retention of ADH activity was investigated at different drying temperatures. When mannitol was used, the encapsulated ADH was found inactive in all the dried powders. This is presumably due to the quick crystallization of mannitol during spray drying that resulted in the impairment of enzyme protection ability in comparison to its amorphous form. Maltodextin (dextrose equivalent = 11) was used to reduce the crystallization of mannitol. The addition of maltodextrin increased ADH activity and drastically changed the powder X-ray diffractogram of the spray-dried powders.

  7. Glutamate oxidation in astrocytes: Roles of glutamate dehydrogenase and aminotransferases

    DEFF Research Database (Denmark)

    McKenna, Mary C; Stridh, Malin H; McNair, Laura Frendrup;

    2016-01-01

    The cellular distribution of transporters and enzymes related to glutamate metabolism led to the concept of the glutamate–glutamine cycle. Glutamate is released as a neurotransmitter and taken up primarily by astrocytes ensheathing the synapses. The glutamate carbon skeleton is transferred back...... oxidative degradation; thus, quantitative formation of glutamine from the glutamate taken up is not possible. Oxidation of glutamate is initiated by transamination catalyzed by an aminotransferase, or oxidative deamination catalyzed by glutamate dehydrogenase (GDH). We discuss methods available to elucidate...... the enzymes that mediate this conversion. Methods include pharmacological tools such as the transaminase inhibitor aminooxyacetic acid, studies using GDH knockout mice, and siRNA-mediated knockdown of GDH in astrocytes. Studies in brain slices incubated with [15N]glutamate demonstrated activity of GDH...

  8. Kinetics of myoglobin redox form stabilization by malate dehydrogenase.

    Science.gov (United States)

    Mohan, Anand; Muthukrishnan, S; Hunt, Melvin C; Barstow, Thomas J; Houser, Terry A

    2010-06-09

    This study reports the reduction of metmyoglobin (MMb) via oxidation of malate to oxaloacetate and the regeneration of reduced nicotinamide adenine dinucleotide (NADH) via malate dehydrogenase (MDH). Two experiments were conducted to evaluate a malate-MDH-NADH system as a possible mechanism for MMb reduction. In experiment 1, kinetics of MDH and MMb reduction were determined, and the results showed that increasing concentrations of oxidized nicotinamide adenine dinucleotide (NAD(+)) and l-malate also increased (p malate and NAD(+) added. Reduction of MMb in the muscle extracts via MDH was NAD(+), malate, and extract concentration dependent (p malate can replenish NADH via MDH activity in post-mortem muscle, ultimately resulting in a more functional meat color.

  9. In vitro interaction between psychotropic drugs and alcohol dehydrogenase activity.

    Science.gov (United States)

    Roig, M G; Bello, F; Burguillo, F J; Cachaza, J M; Kennedy, J F

    1991-03-01

    A series of CNS-stimulating and -depressant drugs have been studied for their in vitro interaction with horse liver alcohol dehydrogenase (ADH) activity. The depressant drugs studied included barbital, phenobarbital, thiopental, nitrazepam, chlorpromazine, sulpiride, clomethiazole, Li2CO3, diazepam, phenytoin, ethosuximide, morphine, and codeine. The stimulant drugs were theophylline, caffeine, amphetamine, imipramine, chlorimipramine, amitriptyline, and tranylcypromine. The results were as follows. First, ADH activity was inhibited by the action of chlorpromazine, tranylcypromine, imipramine, chlorimipramine, amitriptyline, sulpiride, amphetamine, codeine, ethosuximide, morphine, clomethiazole, nitrazepam, Li2CO3, theophylline, and phenobarbital, in descending order of inhibitory effect. Second, inhibition followed by activation of ADH activity was observed for imipramine and chlorimipramine. Third, activation of ADH activity was observed for phenytoin. Finally, the following drugs were not seen to exert any effect on ADH activity: barbital, thiopental, diazepam, and caffeine.

  10. A Case of Hyperammonemia Associated with High Dihydropyrimidine Dehydrogenase Activity

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    Keiki Nagaharu

    2016-01-01

    Full Text Available Over the past decades, 5-Fluorouracil (5-FU has been widely used to treat several types of carcinoma, including esophageal squamous cell carcinoma. In addition to its common side effects, including diarrhea, mucositis, neutropenia, and anemia, 5-FU treatment has also been reported to cause hyperammonemia. However, the exact mechanism responsible for 5-FU-induced hyperammonemia remains unknown. We encountered an esophageal carcinoma patient who developed hyperammonemia when receiving 5-FU-containing chemotherapy but did not exhibit any of the other common adverse effects of 5-FU treatment. At the onset of hyperammonemia, laboratory tests revealed high dihydropyrimidine dehydrogenase (DPD activity and rapid 5-FU clearance. Our findings suggested that 5-FU hypermetabolism may be one of the key mechanisms responsible for hyperammonemia during 5-FU treatment.

  11. Mechanistic enzymology of CO dehydrogenase from Clostridium thermoaceticum

    Energy Technology Data Exchange (ETDEWEB)

    Ragsdale, S.W.

    1992-01-01

    The final steps in acetyl-CoA biosynthesis by anaerobic bacteria are performed by carbon monoxide dehydrogenase (CODH), a nickel/iron-sulfur protein. An important achievement was to establish conditions under which acetyl-CoA synthesis by purified enzymes equals the in vivo rate of acetate synthesis. Under these optimized conditions we established that the rate limiting step in the synthesis of acetyl-CoA from methyl-H[sub 4]folate, CO and CoA is likely to be the methylation of CODH by the methylated corrinoid/iron-sulfur protein. We then focused on stopped flow studies of this rate limiting transmethylation reaction and established its mechanism. We have studied the carbonylation of CODH by infrared and resonance Raman spectroscopy and determined that the [Ni-Fe[sup 3-4]S[sub 4

  12. Crystallographic analysis of FAD-dependent glucose dehydrogenase.

    Science.gov (United States)

    Komori, Hirofumi; Inaka, Koji; Furubayashi, Naoki; Honda, Michinari; Higuchi, Yoshiki

    2015-08-01

    An FAD-dependent glucose dehydrogenase (GDH) from Aspergillus terreus was purified and crystallized at 293 K using the sitting-drop vapour-diffusion method. A data set was collected to a resolution of 1.6 Å from a single crystal at 100 K using a rotating-anode X-ray source. The crystal belonged to space group P21, with unit-cell parameters a = 56.56, b = 135.74, c = 74.13 Å, β = 90.37°. The asymmetric unit contained two molecules of GDH. The Matthews coefficient was calculated to be 2.2 Å(3) Da(-1) and the solvent content was estimated to be 44%.

  13. Conjugated bilirubin in neonates with glucose-6-phosphate dehydrogenase deficiency.

    Science.gov (United States)

    Kaplan, M; Rubaltelli, F F; Hammerman, C; Vilei, M T; Leiter, C; Abramov, A; Muraca, M

    1996-05-01

    We used a system capable of measuring conjugated bilirubin and its monoconjugated and diconjugated fractions in serum to assess bilirubin conjugation in 29 glucose-6-phosphate dehydrogenase (G6PD)-deficient, term, male newborn infants and 35 control subjects; all had serum bilirubin levels > or = 256 mumol/L (15 mg/dI). The median value for diconjugated bilirubin was lower in the G6PD-deficient neonates than in control subjects (0.06 (range 0.00 to 1.84) vs 0.21 (range 0.00 to 1.02) mumol/L, p = 0.006). Diglucuronide was undetectable in 11 (38.9%) of the G6PD-deficient infants versus 3 (8.6%) of the control subjects (p = 0.015). These findings imply a partial defect of bilirubin conjugation not previously demonstrated in G6PD-deficient newborn infants.

  14. Lactate dehydrogenase (LDH isoenzymes patterns in ocular tumours

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    Singh Rajendra

    1991-01-01

    Full Text Available Estimation of lactate dehydrogenase (LDH isoenzymes in the serum and aqueous humor was carried out in 15 cases of benign ocular tumour, 15 cases of malignant tumor and 15 normal cases. Cases of both sexes aged between 1 year and 75 years were included. LDH, isoenzymes specially LDH4 and LDH5 are higher and LDH1 and LDH2 lower in sera of patients with malignant tumor specially retinoblastoma as compared to benign tumor cases and control cases. LDH isoenzymes in aqueous humor are significantly higher and show a characteristic pattern in retinoblastoma cases, the concentration was presumably too low in the control, malignant tumor other than retinoblastoma and benign tumor cases as its fractionation was not possible.

  15. Pyruvate Dehydrogenase Kinase as a Novel Therapeutic Target in Oncology

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    Gopinath eSutendra

    2013-03-01

    Full Text Available Current drug development in oncology is non-selective as it typically focuses on pathways essential for the survival of all dividing cells. The unique metabolic profile of cancer, which is characterized by increased glycolysis and suppressed mitochondrial glucose oxidation provides cancer cells with a proliferative advantage, conducive with apoptosis resistance and even increased angiogenesis. Recent evidence suggests that targeting the cancer-specific metabolic and mitochondrial remodeling may offer selectivity in cancer treatment. Pyruvate dehydrogenase kinase (PDK is a mitochondrial enzyme that is activated in a variety of cancers and results in the selective inhibition of pyruvate dehydrogenase (PDH, a complex of enzymes that converts cytosolic pyruvate to mitochondrial acetyl-CoA, the substrate for the Krebs’ cycle. Inhibition of PDK with either small interfering RNAs or the orphan drug dichloroacetate (DCA shifts the metabolism of cancer cells from glycolysis to glucose oxidation and reverses the suppression of mitochondria-dependent apoptosis. In addition, this therapeutic strategy increases the production of diffusible Krebs’ cycle intermediates and mitochondria-derived reactive oxygen species (mROS, activating p53 or inhibiting pro-proliferative and pro-angiogenic transcription factors like nuclear factor of activated T-cells (NFAT and hypoxia-inducible factor 1α (HIF1α. These effects result in decreased tumor growth and angiogenesis in a variety of cancers with high selectivity. In a small but mechanistic clinical trial in patients with glioblastoma, a highly aggressive and vascular form of brain cancer, DCA decreased tumor angiogenesis and tumor growth, suggesting that metabolic targeting therapies can be translated directly to patients. Therefore, reversing the mitochondrial suppression with metabolic-modulating drugs, like PDK inhibitors holds promise in the rapidly expanding field of metabolic oncology.

  16. Biochemical and structural characterization of Plasmodium falciparum glutamate dehydrogenase 2.

    Science.gov (United States)

    Zocher, Kathleen; Fritz-Wolf, Karin; Kehr, Sebastian; Fischer, Marina; Rahlfs, Stefan; Becker, Katja

    2012-05-01

    Glutamate dehydrogenases (GDHs) play key roles in cellular redox, amino acid, and energy metabolism, thus representing potential targets for pharmacological interventions. Here we studied the functional network provided by the three known glutamate dehydrogenases of the malaria parasite Plasmodium falciparum. The recombinant production of the previously described PfGDH1 as hexahistidyl-tagged proteins was optimized. Additionally, PfGDH2 was cloned, recombinantly produced, and characterized. Like PfGDH1, PfGDH2 is an NADP(H)-dependent enzyme with a specific activity comparable to PfGDH1 but with slightly higher K(m) values for its substrates. The three-dimensional structure of hexameric PfGDH2 was solved to 3.1 Å resolution. The overall structure shows high similarity with PfGDH1 but with significant differences occurring at the subunit interface. As in mammalian GDH1, in PfGDH2 the subunit-subunit interactions are mainly assisted by hydrogen bonds and hydrophobic interactions, whereas in PfGDH1 these contacts are mediated by networks of salt bridges and hydrogen bonds. In accordance with this, the known bovine GDH inhibitors hexachlorophene, GW5074, and bithionol were more effective on PfGDH2 than on PfGDH1. Subcellular localization was determined for all three plasmodial GDHs by fusion with the green fluorescent protein. Based on our data, PfGDH1 and PfGDH3 are cytosolic proteins whereas PfGDH2 clearly localizes to the apicoplast, a plastid-like organelle specific for apicomplexan parasites. This study provides new insights into the structure and function of GDH isoenzymes of P. falciparum, which represent potential targets for the development of novel antimalarial drugs.

  17. Redesigning the substrate specificity of an enzyme: isocitrate dehydrogenase.

    Science.gov (United States)

    Doyle, S A; Fung, S Y; Koshland, D E

    2000-11-21

    Despite the structural similarities between isocitrate and isopropylmalate, isocitrate dehydrogenase (IDH) exhibits a strong preference for its natural substrate. Using a combination of rational and random mutagenesis, we have engineered IDH to use isopropylmalate as a substrate. Rationally designed mutations were based on comparison of IDH to a similar enzyme, isopropylmalate dehydrogenase (IPMDH). A chimeric enzyme that replaced an active site loop-helix motif with IPMDH sequences exhibited no activity toward isopropylmalate, and site-directed mutants that replaced IDH residues with their IPMDH equivalents only showed small improvements in k(cat). Random mutants targeted the IDH active site at positions 113 (substituted with glutamate), 115, and 116 (both randomized) and were screened for activity toward isopropylmalate. Six mutants were identified that exhibited up to an 8-fold improvement in k(cat) and increased the apparent binding affinity by as much as a factor of 80. In addition to the S113E mutation, five other mutants contained substitutions at positions 115 and/or 116. Most small hydrophobic substitutions at position 116 improved activity, possibly by generating space to accommodate the isopropyl group of isopropylmalate; however, substitution with serine yielded the most improvement in k(cat). Only two substitutions were identified at position 115, which suggests a more specific role for the wild-type asparagine residue in the utilization of isopropylmalate. Since interactions between neighboring residues in this region greatly influenced the effects of each other in unexpected ways, structural solutions were best identified in combinations, as allowed by random mutagenesis.

  18. Evaluation of Serum Lactate Dehydrogenase Activity in a Virtual Environment

    Directory of Open Access Journals (Sweden)

    V.M.T. Trindade

    2013-05-01

    Full Text Available Introduction: Lactate dehydrogenase is a citosolic enzyme involved in reversible transformation of pyruvate to lactate. It participates in anaerobic glycolysis of skeletal muscle and red blood cells, in liver gluconeogenesis and in aerobic metabolism of heart muscle. The determination of its activity helps in the diagnosis of various diseases, because it is increased in serum of patients suffering from myocardial infarction, acute hepatitis, muscular dystrophy and cancer. This paper presents a learning object, mediated by computer, which contains the simulation of the laboratory determination serum lactate dehydrogenase activity measured by the spectrophotometric method, based in the decrease of absorbance at 340 nm. Materials and Methods: Initially, pictures and videos were obtained recording the procedure of the methodology. The most representative images were selected, edited and inserted into an animation developed with the aid of the tool Adobe ® Flash ® CS3. The validation of the object was performed by the students of Biochemistry I (Pharmacy-UFRGS from the second semester of 2009 and both of 2010. Results and Discussion: The analysis of students' answers revealed that 80% attributed the excellence of the navigation program, the display format and to aid in learning. Conclusion: Therefore, this software can be considered an adequate teaching resource as well as an innovative support in the construction of theoretical and practical knowledge of Biochemistry. Available at: http://www6.ufrgs.br/gcoeb/LDH

  19. Lactate dehydrogenase concentration in nasal wash fluid indicates severity of rhinovirus-induced wheezy bronchitis in preschool children.

    Science.gov (United States)

    Cangiano, Giulia; Proietti, Elena; Kronig, Marie Noelle; Kieninger, Elisabeth; Sadeghi, Christine D; Gorgievski, Meri; Barbani, Maria Teresa; Midulla, Fabio; Tapparel, Caroline; Kaiser, Laurent; Alves, Marco P; Regamey, Nicolas

    2014-12-01

    The clinical course of rhinovirus (RV)-associated wheezing illnesses is difficult to predict. We measured lactate dehydrogenase concentrations, RV load, antiviral and proinflammatory cytokines in nasal washes obtained from 126 preschool children with RV wheezy bronchitis. lactate dehydrogenase values were inversely associated with subsequent need for oxygen therapy. lactate dehydrogenase may be a useful biomarker predicting disease severity in RV wheezy bronchitis.

  20. Group III alcohol dehydrogenase from Pectobacterium atrosepticum: insights into enzymatic activity and organization of the metal ion-containing region.

    Science.gov (United States)

    Elleuche, Skander; Fodor, Krisztian; von der Heyde, Amélie; Klippel, Barbara; Wilmanns, Matthias; Antranikian, Garabed

    2014-05-01

    NAD(P)(+)-dependent alcohol dehydrogenases (ADH) are widely distributed in all phyla. These proteins can be assigned to three nonhomologous groups of isozymes, with group III being highly diverse with regards to catalytic activity and primary structure. Members of group III ADHs share a conserved stretch of amino acid residues important for cofactor binding and metal ion coordination, while sequence identities for complete proteins are highly diverse (90 %). A putative group III ADH PaYqhD has been identified in BLAST analysis from the plant pathogenic enterobacterium Pectobacterium atrosepticum. The PaYqhD gene was expressed in the heterologous host Escherichia coli, and the recombinant protein was purified in a two-step purification procedure to homogeneity indicating an obligate dimerization of monomers. Four conserved amino acid residues involved in metal ion coordination were substituted with alanine, and their importance for catalytic activity was confirmed by circular dichroism spectrum determination, in vitro, and growth experiments. PaYqhD exhibits optimal activity at 40 °C with short carbon chain aldehyde compounds and NADPH as cofactor indicating the enzyme to be an aldehyde reductase. No oxidative activities towards alcoholic compounds were detectable. EDTA completely inhibited catalytic activity and was fully restored by the addition of Co(2+). Activity measurements together with sequence alignments and structure analysis confirmed that PaYqhD belongs to the butanol dehydrogenase-like enzymes within group III of ADHs.

  1. Fusarium graminearum pyruvate dehydrogenase kinase 1 (FgPDK1 Is Critical for Conidiation, Mycelium Growth, and Pathogenicity.

    Directory of Open Access Journals (Sweden)

    Tao Gao

    Full Text Available Pyruvate dehydrogenase kinase (PDK is an important mitochondrial enzyme that blocks the production of acetyl-CoA by selectively inhibiting the activity of pyruvate dehydrogenase (PDH through phosphorylation. PDK is an effectively therapeutic target in cancer cells, but the physiological roles of PDK in phytopathogens are largely unknown. To address these gaps, a PDK gene (FgPDK1 was isolated from Fusarium graminearum that is an economically important pathogen infecting cereals. The deletion of FgPDK1 in F. graminearum resulted in the increase in PDH activity, coinciding with several phenotypic defects, such as growth retardation, failure in perithecia and conidia production, and increase in pigment formation. The ΔFgPDK1 mutants showed enhanced sensitivity to osmotic stress and cell membrane-damaging agent. Physiological detection indicated that reactive oxygen species (ROS accumulation and plasma membrane damage (indicated by PI staining, lipid peroxidation, and electrolyte leakage occurred in ΔFgPDK1 mutants. The deletion of FgPDK1 also prohibited the production of deoxynivalenol (DON and pathogenicity of F. graminearum, which may resulted from the decrease in the expression of Tri6. Taken together, this study firstly identified the vital roles of FgPDK1 in the development of phytopathogen F. graminearum, which may provide a potentially novel clue for target-directed development of agricultural fungicides.

  2. An experimental test for lineage-specific position effects on alcohol dehydrogenase (Adh) genes in Drosophila

    Science.gov (United States)

    Siegal, Mark L.; Hartl, Daniel L.

    1998-01-01

    Independent transgene insertions differ in expression based on their location in the genome; these position effects are of interest because they reflect the influence of genome organization on gene regulation. Position effects also represent potentially insurmountable obstacles to the rigorous functional comparison of homologous genes from different species because (i) quantitative variation in expression of each gene across genomic positions (generalized position effects, or GPEs) may overwhelm differences between the genes of interest, or (ii) divergent genes may be differentially sensitive to position effects, reflecting unique interactions between each gene and its genomic milieu (lineage-specific position effects, or LSPEs). We have investigated both types of position-effect variation by applying our method of transgene coplacement, which allows comparisons of transgenes in the same position in the genome of Drosophila melanogaster. Here we report an experimental test for LSPE in Drosophila. The alcohol dehydrogenase (Adh) genes of D. melanogaster and Drosophila affinidisjuncta differ in both tissue distribution and amounts of ADH activity. Despite this striking regulatory divergence, we found a very high correlation in overall ADH activity between the genes of the two species when placed in the same genomic position as assayed in otherwise Adh-null adults and larvae. These results argue against the influence of LSPE for these sequences, although the effects of GPE are significant. Our new findings validate the coplacement approach and show that it greatly magnifies the power to detect differences in expression between transgenes. Transgene coplacement thus dramatically extends the range of functional and evolutionary questions that can be addressed by transgenic technology. PMID:9861000

  3. Deficiency of retinaldehyde dehydrogenase 1 induces BMP2 and increases bone mass in vivo.

    Directory of Open Access Journals (Sweden)

    Shriram Nallamshetty

    Full Text Available The effects of retinoids, the structural derivatives of vitamin A (retinol, on post-natal peak bone density acquisition and skeletal remodeling are complex and compartment specific. Emerging data indicates that retinoids, such as all trans retinoic acid (ATRA and its precursor all trans retinaldehyde (Rald, exhibit distinct and divergent transcriptional effects in metabolism. Despite these observations, the role of enzymes that control retinoid metabolism in bone remains undefined. In this study, we examined the skeletal phenotype of mice deficient in retinaldehyde dehydrogenase 1 (Aldh1a1, the enzyme responsible for converting Rald to ATRA in adult animals. Bone densitometry and micro-computed tomography (µCT demonstrated that Aldh1a1-deficient (Aldh1a1(-/- female mice had higher trabecular and cortical bone mass compared to age and sex-matched control C57Bl/6 wild type (WT mice at multiple time points. Histomorphometry confirmed increased cortical bone thickness and demonstrated significantly higher bone marrow adiposity in Aldh1a1(-/- mice. In serum assays, Aldh1a1(-/- mice also had higher serum IGF-1 levels. In vitro, primary Aldh1a1(-/- mesenchymal stem cells (MSCs expressed significantly higher levels of bone morphogenetic protein 2 (BMP2 and demonstrated enhanced osteoblastogenesis and adipogenesis versus WT MSCs. BMP2 was also expressed at higher levels in the femurs and tibias of Aldh1a1(-/- mice with accompanying induction of BMP2-regulated responses, including expression of Runx2 and alkaline phosphatase, and Smad phosphorylation. In vitro, Rald, which accumulates in Aldh1a1(-/- mice, potently induced BMP2 in WT MSCs in a retinoic acid receptor (RAR-dependent manner, suggesting that Rald is involved in the BMP2 increases seen in Aldh1a1 deficiency in vivo. Collectively, these data implicate Aldh1a1 as a novel determinant of cortical bone density and marrow adiposity in the skeleton in vivo through modulation of BMP signaling.

  4. Functional analysis of a cinnamyl alcohol dehydrogenase involved in lignin biosynthesis in wheat.

    Science.gov (United States)

    Ma, Qing-Hu

    2010-06-01

    Cinnamyl alcohol dehydrogenase (CAD) catalyses the final step in the biosynthesis of monolignols. In the present study, a cDNA encoding a CAD was isolated from wheat, designated as TaCAD1. A genome-wide data mining in the wheat EST database revealed another 10 CAD-like homologues, namely TaCAD2 to TaCAD11. A phylogenetic analysis showed that TaCAD1 belonged to the bona fide CAD group involved in lignin synthesis. Two other putative CADs from the wheat genome (TaCAD2 and TaCAD4) also belonged to this group and were very close to TaCAD1, but lacked C-terminal domain, suggesting that they are pseudogenes. DNA gel blot analysis for the wheat genome showed two to three copies of CAD related to TaCAD1, but RNA gel blot analysis revealed only single band for TaCAD1, which was highly expressed in stem, with quite low expression in leaf and undetectable expression in root. The predicted three-dimension structure of TaCAD1 resembled that of AtCAD5, but two amino acid substitutions were identified in the substrate binding region. Recombinant TaCAD1 protein used coniferyl aldehyde as the most favoured substrate, also showed high efficiencies toward sinapyl and p-coumaryl aldehydes. TaCAD1 was an enzyme being pH-dependent and temperature-sensitive, and showing a typical random catalysing mechanism. At the milky stage of wheat, TaCAD1 mRNA abundance, protein level and enzyme activity in stem tissues were higher in a lodging-resistant cultivar (H4546) than in lodging-sensitive cultivar (C6001). These properties were correlated to the lignin contents and lodging indices of the two cultivars. These data suggest that TaCAD1 is the predominant CAD in wheat stem for lignin biosynthesis and is critical for lodging resistance.

  5. ALCOHOL AND ALDEHYDE DEHYDROGENASES CONTRIBUTE TO SEX-RELATED DIFFERENCES IN CLEARANCE OF ZOLPIDEM IN RATS

    Directory of Open Access Journals (Sweden)

    Cody J Peer

    2016-08-01

    Full Text Available Objectives:  The recommended zolpidem starting dose was lowered in females (5mg vs 10mg since side effects were more frequent and severe than those of males; the mechanism underlying sex differences in pharmacokinetics (PK is unknown.  We hypothesized that such differences were caused by known sex-related variability in alcohol dehydrogenase (ADH expression. Methods:  Male, female, and castrated male rats were administered 2.6 mg/kg zolpidem, +/- disulfiram (ADH/ALDH pathway inhibitor to compare PK changes induced by sex and gonadal hormones.  PK analyses were conducted in rat plasma and rat brain. Key findings:  Sex differences in PK were evident: females had a higher CMAX (112.4 vs 68.1 ug/L and AUC (537.8 vs 231.8 hr*ug/L than uncastrated males.  Castration induced an earlier TMAX (0.25 vs 1 hr, greater CMAX (109.1 vs 68.1 ug/L, and a corresponding AUC increase (339.7 vs 231.8 hr*ug/L.  Administration of disulfiram caused more drastic CMAX and TMAX changes in male vs female rats that mirrored the effects of castration on first-pass metabolism, suggesting that the observed PK differences may be caused by ADH/ALDH expression. Brain concentrations paralleled plasma concentrations.Conclusions:  These findings indicate that sex differences in zolpidem PK are influenced by variation in the expression of ADH/ALDH due to gonadal androgens.

  6. Characterization Analysis of Response of Alcohol Dehydrogenase Gene (ADH1 in Coix lacroyma>/em> jobi L. to Waterlogging Stress

    Directory of Open Access Journals (Sweden)

    Daqing-chen

    2012-12-01

    Full Text Available The aim of this study was focused on response of Alcohol Dehydrogenase gene (ADH1 in Coix to waterlogging stress. Based on the conserved sequence of Alcphol Dehydrogenase (ADH1 gene in maize, rice, and wheat, primers were designed to isolate theADH1 product. The full-length sequence of cDNA was firstly cloned by using RACE technology. The acquired gene contains an open reading frame (ORF, DQ455071.2 of 1140 bp and encodes 379 amino acids residues with the molecular weight and theoretical isoelectric of 40.965 and 6.13 KD, respectively. The BlastN/P analysis revealed that the sequence was highly homologous with gramineous plants such as ADH1 in maize, rice, and wheat. Moreover, it could be found in the phylogenetic tree that the origin of ADH1- encoding protein was most close to gramineous plants. It was predicted that it had at least two standard transmembrane segments, and the three-dimensional structure had 54.38% consistency with the reference model of 2 fzwa. The characteristic belt of ADH1 target protein was obtained by prokaryotic expression. Semi-quantitative analysis suggested thatADH1 gene expression was induced by waterlogging, and the expression in the root tip reached the highest level after 4 h of waterlogging, while ADH enzyme activity was also increased after waterlogging and reached the highest level after 6 h. Significant difference occurred in the ADH enzyme activities at different treatment time (p<0.05. Results indicated that ADH1 was sensitive to waterlogging and took part in tolerant and adaptive process under anaerobic environment.

  7. Characterisation of 11β-hydroxysteroid dehydrogenase 1 in human orbital adipose tissue: a comparison with subcutaneous and omental fat

    Science.gov (United States)

    Bujalska, Iwona J; Durrani, Omar M; Abbott, Joseph; Onyimba, Claire U; Khosla, Pamela; Moosavi, Areeb H; Reuser, Tristan T Q; Stewart, Paul M; Tomlinson, Jeremy W; Walker, Elizabeth A; Rauz, Saaeha

    2007-01-01

    Glucocorticoids (GCs) have a profound effect on adipose biology increasing tissue mass causing central obesity. The pre-receptor regulation of GCs by 11β-hydroxysteroid dehydrogenase type 1 (11β-HSD1) that activates cortisol from cortisone has been postulated as a fundamental mechanism underlying the metabolic syndrome mediating adipocyte hyperplasia and hypertrophy in the omental (OM) depot. Orbital adipose tissue (OF) is the site of intense inflammation and tissue remodelling in several orbital inflammatory disease states. In this study, we describe features of the GC metabolic pathways in normal human OF depot and compare it with subcutaneous (SC) and OM depots. Using an automated histological characterisation technique, OF adipocytes were found to be significantly smaller (parameters: area, maximum diameter and perimeter) than OM and SC adipocytes (P<0·001). Although immunohistochemical analyses demonstrated resident CD68+ cells in all three whole tissue adipose depots, OF CD68 mRNA and protein expression exceeded that of OM and SC (mRNA, P<0·05; protein, P<0·001). In addition, there was higher expression of glucocorticoid receptor (GR)α mRNA in the OF whole tissue depot (P<0·05). Conversely, 11β-HSD1 mRNA together with the markers of late adipocyte differentiation (FABP4 and G3PDH) were significantly lower in OF. Primary cultures of OF preadipocytes demonstrated predominant 11β-HSD1 oxo-reductase activity with minimal dehydrogenase activity. Orbital adipocytes are smaller, less differentiated, and express low levels of 11β-HSD1 but abundant GRα compared with SC and OM. OF harbours a large CD68+ population. These characteristics define an orbital microenvironment that has the potential to respond to sight-threatening orbital inflammatory disease. PMID:17283228

  8. Characterisation of 11beta-hydroxysteroid dehydrogenase 1 in human orbital adipose tissue: a comparison with subcutaneous and omental fat.

    Science.gov (United States)

    Bujalska, Iwona J; Durrani, Omar M; Abbott, Joseph; Onyimba, Claire U; Khosla, Pamela; Moosavi, Areeb H; Reuser, Tristan T Q; Stewart, Paul M; Tomlinson, Jeremy W; Walker, Elizabeth A; Rauz, Saaeha

    2007-02-01

    Glucocorticoids (GCs) have a profound effect on adipose biology increasing tissue mass causing central obesity. The pre-receptor regulation of GCs by 11beta-hydroxysteroid dehydrogenase type 1 (11beta-HSD1) that activates cortisol from cortisone has been postulated as a fundamental mechanism underlying the metabolic syndrome mediating adipocyte hyperplasia and hypertrophy in the omental (OM) depot. Orbital adipose tissue (OF) is the site of intense inflammation and tissue remodelling in several orbital inflammatory disease states. In this study, we describe features of the GC metabolic pathways in normal human OF depot and compare it with subcutaneous (SC) and OM depots. Using an automated histological characterisation technique, OF adipocytes were found to be significantly smaller (parameters: area, maximum diameter and perimeter) than OM and SC adipocytes (P<0 x 001). Although immunohistochemical analyses demonstrated resident CD68+ cells in all three whole tissue adipose depots, OF CD68 mRNA and protein expression exceeded that of OM and SC (mRNA, P<0 x 05; protein, P<0 x 001). In addition, there was higher expression of glucocorticoid receptor (GR)alpha mRNA in the OF whole tissue depot (P<0 x 05). Conversely, 11beta-HSD1 mRNA together with the markers of late adipocyte differentiation (FABP4 and G3PDH) were significantly lower in OF. Primary cultures of OF preadipocytes demonstrated predominant 11beta-HSD1 oxo-reductase activity with minimal dehydrogenase activity. Orbital adipocytes are smaller, less differentiated, and express low levels of 11beta-HSD1 but abundant GRalpha compared with SC and OM. OF harbours a large CD68+ population. These characteristics define an orbital microenvironment that has the potential to respond to sight-threatening orbital inflammatory disease.

  9. Polymorphisms of alcohol dehydrogenase-2 and aldehyde dehydrogenase-2 and esophageal cancer risk in Southeast Chinese males

    Institute of Scientific and Technical Information of China (English)

    Jian-Hua Ding; Su-Ping Li; Hai-Xia Cao; Jian-Zhong Wu; Chang-Ming Gao; Ping Su; Yan-Ting Liu; Jian-Nong Zhou; Jun Chang; Gen-Hong Yao

    2009-01-01

    AIM: To evaluate the impact of alcohol dehydrogenase-2 (ADH2) and aldehyde dehydrogenase-2 (ALDH2) polymorphisms on esophageal cancer susceptibility in Southeast Chinese males. METHODS: Two hundred and twenty-one esophageal cancer patients and 191 healthy controls from Taixing city in Jiangsu Province were enrolled in this study. ADH2 and ALDH2 genotypes were examined by polymerase chain reaction and denaturing highperformance liquid chromatography. Unconditional logistic regression was used to calculate the odds ratios (OR) and 95% confidence interval (CI). RESULTS: The ADH G allele carriers were more susceptible to esophageal cancer, but no association was found between ADH2 genotypes and risk of esophageal cancer when disregarding alcohol drinking status. Regardless of ADH2 genotype, ALDH2G/A or A/A carriers had significantly increased risk of developing esophageal cancer, with homozygous individuals showing higher esophageal cancer risk than those who were heterozygous. A significant interaction between ALDH2 and drinking was detected regarding esophageal cancer risk; the OR was 3.05 (95% CI: 1.49-6.25). Compared with non-drinkers carrying both ALDH2 G/G and ADH2 A/A, drinkers carrying both ALDH2 A allele and ADH2 G allele showed a significantly higher risk of developing esophageal cancer (OR = 8.36, 95% CI: 2.98-23.46).CONCLUSION: Both ADH2 G allele and ALDH2 A allele significantly increase the risk of esophageal cancer development in Southeast Chinese males. ALDH2 A allele significantly increases the risk of esophageal cancer development especially in alcohol drinkers. Alcohol drinkers carrying both ADH2 G allele and ALDH2 A allele have a higher risk of developing esophageal cancer.

  10. Improved production of propionic acid in Propionibacterium jensenii via combinational overexpression of glycerol dehydrogenase and malate dehydrogenase from Klebsiella pneumoniae.

    Science.gov (United States)

    Liu, Long; Zhuge, Xin; Shin, Hyun-Dong; Chen, Rachel R; Li, Jianghua; Du, Guocheng; Chen, Jian

    2015-04-01

    Microbial production of propionic acid (PA), an important chemical building block used as a preservative and chemical intermediate, has gained increasing attention for its environmental friendliness over traditional petrochemical processes. In previous studies, we constructed a shuttle vector as a useful tool for engineering Propionibacterium jensenii, a potential candidate for efficient PA synthesis. In this study, we identified the key metabolites for PA synthesis in P. jensenii by examining the influence of metabolic intermediate addition on PA synthesis with glycerol as a carbon source under anaerobic conditions. We also further improved PA production via the overexpression of the identified corresponding enzymes, namely, glycerol dehydrogenase (GDH), malate dehydrogenase (MDH), and fumarate hydratase (FUM). Compared to those in wild-type P. jensenii, the activities of these enzymes in the engineered strains were 2.91- ± 0.17- to 8.12- ± 0.37-fold higher. The transcription levels of the corresponding enzymes in the engineered strains were 2.85- ± 0.19- to 8.07- ± 0.63-fold higher than those in the wild type. The coexpression of GDH and MDH increased the PA titer from 26.95 ± 1.21 g/liter in wild-type P. jensenii to 39.43 ± 1.90 g/liter in the engineered strains. This study identified the key metabolic nodes limiting PA overproduction in P. jensenii and further improved PA titers via the coexpression of GDH and MDH, making the engineered P. jensenii strain a potential industrial producer of PA.

  11. Dimerization and enzymatic activity of fungal 17β-hydroxysteroid dehydrogenase from the short-chain dehydrogenase/reductase superfamily

    Directory of Open Access Journals (Sweden)

    Kristan Katja

    2005-12-01

    Full Text Available Abstract Background 17β-hydroxysteroid dehydrogenase from the fungus Cochliobolus lunatus (17β-HSDcl is a member of the short-chain dehydrogenase/reductase (SDR superfamily. SDR proteins usually function as dimers or tetramers and 17β-HSDcl is also a homodimer under native conditions. Results We have investigated here which secondary structure elements are involved in the dimerization of 17β-HSDcl and examined the importance of dimerization for the enzyme activity. Sequence similarity with trihydroxynaphthalene reductase from Magnaporthe grisea indicated that Arg129 and His111 from the αE-helices interact with the Asp121, Glu117 and Asp187 residues from the αE and αF-helices of the neighbouring subunit. The Arg129Asp and His111Leu mutations both rendered 17β-HSDcl monomeric, while the mutant 17β-HSDcl-His111Ala was dimeric. Circular dichroism spectroscopy analysis confirmed the conservation of the secondary structure in both monomers. The three mutant proteins all bound coenzyme, as shown by fluorescence quenching in the presence of NADP+, but both monomers showed no enzymatic activity. Conclusion We have shown by site-directed mutagenesis and structure/function analysis that 17β-HSDcl dimerization involves the αE and αF helices of both subunits. Neighbouring subunits are connected through hydrophobic interactions, H-bonds and salt bridges involving amino acid residues His111 and Arg129. Since the substitutions of these two amino acid residues lead to inactive monomers with conserved secondary structure, we suggest dimerization is a prerequisite for catalysis. A detailed understanding of this dimerization could lead to the development of compounds that will specifically prevent dimerization, thereby serving as a new type of inhibitor.

  12. The Glutamate Dehydrogenase Pathway and Its Roles in Cell and Tissue Biology in Health and Disease

    Science.gov (United States)

    Plaitakis, Andreas; Kalef-Ezra, Ester; Kotzamani, Dimitra; Zaganas, Ioannis; Spanaki, Cleanthe

    2017-01-01

    Glutamate dehydrogenase (GDH) is a hexameric enzyme that catalyzes the reversible conversion of glutamate to α-ketoglutarate and ammonia while reducing NAD(P)+ to NAD(P)H. It is found in all living organisms serving both catabolic and anabolic reactions. In mammalian tissues, oxidative deamination of glutamate via GDH generates α-ketoglutarate, which is metabolized by the Krebs cycle, leading to the synthesis of ATP. In addition, the GDH pathway is linked to diverse cellular processes, including ammonia metabolism, acid-base equilibrium, redox homeostasis (via formation of fumarate), lipid biosynthesis (via oxidative generation of citrate), and lactate production. While most mammals possess a single GDH1 protein (hGDH1 in the human) that is highly expressed in the liver, humans and other primates have acquired, via duplication, an hGDH2 isoenzyme with distinct functional properties and tissue expression profile. The novel hGDH2 underwent rapid evolutionary adaptation, acquiring unique properties that enable enhanced enzyme function under conditions inhibitory to its ancestor hGDH1. These are thought to provide a biological advantage to humans with hGDH2 evolution occurring concomitantly with human brain development. hGDH2 is co-expressed with hGDH1 in human brain, kidney, testis and steroidogenic organs, but not in the liver. In human cerebral cortex, hGDH1 and hGDH2 are expressed in astrocytes, the cells responsible for removing and metabolizing transmitter glutamate, and for supplying neurons with glutamine and lactate. In human testis, hGDH2 (but not hGDH1) is densely expressed in the Sertoli cells, known to provide the spermatids with lactate and other nutrients. In steroid producing cells, hGDH1/2 is thought to generate reducing equivalents (NADPH) in the mitochondria for the biosynthesis of steroidal hormones. Lastly, up-regulation of hGDH1/2 expression occurs in cancer, permitting neoplastic cells to utilize glutamine/glutamate for their growth. In

  13. The Glutamate Dehydrogenase Pathway and Its Roles in Cell and Tissue Biology in Health and Disease

    Directory of Open Access Journals (Sweden)

    Andreas Plaitakis

    2017-02-01

    Full Text Available Glutamate dehydrogenase (GDH is a hexameric enzyme that catalyzes the reversible conversion of glutamate to α-ketoglutarate and ammonia while reducing NAD(P+ to NAD(PH. It is found in all living organisms serving both catabolic and anabolic reactions. In mammalian tissues, oxidative deamination of glutamate via GDH generates α-ketoglutarate, which is metabolized by the Krebs cycle, leading to the synthesis of ATP. In addition, the GDH pathway is linked to diverse cellular processes, including ammonia metabolism, acid-base equilibrium, redox homeostasis (via formation of fumarate, lipid biosynthesis (via oxidative generation of citrate, and lactate production. While most mammals possess a single GDH1 protein (hGDH1 in the human that is highly expressed in the liver, humans and other primates have acquired, via duplication, an hGDH2 isoenzyme with distinct functional properties and tissue expression profile. The novel hGDH2 underwent rapid evolutionary adaptation, acquiring unique properties that enable enhanced enzyme function under conditions inhibitory to its ancestor hGDH1. These are thought to provide a biological advantage to humans with hGDH2 evolution occurring concomitantly with human brain development. hGDH2 is co-expressed with hGDH1 in human brain, kidney, testis and steroidogenic organs, but not in the liver. In human cerebral cortex, hGDH1 and hGDH2 are expressed in astrocytes, the cells responsible for removing and metabolizing transmitter glutamate, and for supplying neurons with glutamine and lactate. In human testis, hGDH2 (but not hGDH1 is densely expressed in the Sertoli cells, known to provide the spermatids with lactate and other nutrients. In steroid producing cells, hGDH1/2 is thought to generate reducing equivalents (NADPH in the mitochondria for the biosynthesis of steroidal hormones. Lastly, up-regulation of hGDH1/2 expression occurs in cancer, permitting neoplastic cells to utilize glutamine/glutamate for their growth

  14. The Glutamate Dehydrogenase Pathway and Its Roles in Cell and Tissue Biology in Health and Disease.

    Science.gov (United States)

    Plaitakis, Andreas; Kalef-Ezra, Ester; Kotzamani, Dimitra; Zaganas, Ioannis; Spanaki, Cleanthe

    2017-02-08

    Glutamate dehydrogenase (GDH) is a hexameric enzyme that catalyzes the reversible conversion of glutamate to α-ketoglutarate and ammonia while reducing NAD(P)⁺ to NAD(P)H. It is found in all living organisms serving both catabolic and anabolic reactions. In mammalian tissues, oxidative deamination of glutamate via GDH generates α-ketoglutarate, which is metabolized by the Krebs cycle, leading to the synthesis of ATP. In addition, the GDH pathway is linked to diverse cellular processes, including ammonia metabolism, acid-base equilibrium, redox homeostasis (via formation of fumarate), lipid biosynthesis (via oxidative generation of citrate), and lactate production. While most mammals possess a single GDH1 protein (hGDH1 in the human) that is highly expressed in the liver, humans and other primates have acquired, via duplication, an hGDH2 isoenzyme with distinct functional properties and tissue expression profile. The novel hGDH2 underwent rapid evolutionary adaptation, acquiring unique properties that enable enhanced enzyme function under conditions inhibitory to its ancestor hGDH1. These are thought to provide a biological advantage to humans with hGDH2 evolution occurring concomitantly with human brain development. hGDH2 is co-expressed with hGDH1 in human brain, kidney, testis and steroidogenic organs, but not in the liver. In human cerebral cortex, hGDH1 and hGDH2 are expressed in astrocytes, the cells responsible for removing and metabolizing transmitter glutamate, and for supplying neurons with glutamine and lactate. In human testis, hGDH2 (but not hGDH1) is densely expressed in the Sertoli cells, known to provide the spermatids with lactate and other nutrients. In steroid producing cells, hGDH1/2 is thought to generate reducing equivalents (NADPH) in the mitochondria for the biosynthesis of steroidal hormones. Lastly, up-regulation of hGDH1/2 expression occurs in cancer, permitting neoplastic cells to utilize glutamine/glutamate for their growth. In

  15. Molecular phylogeny and evolution of alcohol dehydrogenase (Adh genes in legumes

    Directory of Open Access Journals (Sweden)

    Ochiai Toshinori

    2005-04-01

    Full Text Available Abstract Background Nuclear genes determine the vast range of phenotypes that are responsible for the adaptive abilities of organisms in nature. Nevertheless, the evolutionary processes that generate the structures and functions of nuclear genes are only now be coming understood. The aim of our study is to isolate the alcohol dehydrogenase (Adh genes in two distantly related legumes, and use these sequences to examine the molecular evolutionary history of this nuclear gene. Results We isolated the expressed Adh genes from two species of legumes, Sophora flavescens Ait. and Wisteria floribunda DC., by a RT-PCR based approach and found a new Adh locus in addition to homologues of the Adh genes found previously in legumes. To examine the evolution of these genes, we compared the species and gene trees and found gene duplication of the Adh loci in the legumes occurred as an ancient event. Conclusion This is the first report revealing that some legume species have at least two Adh gene loci belonging to separate clades. Phylogenetic analyses suggest that these genes resulted from relatively ancient duplication events.

  16. Molecular phylogeny and evolution of alcohol dehydrogenase (Adh) genes in legumes

    Science.gov (United States)

    Fukuda, Tatsuya; Yokoyama, Jun; Nakamura, Toru; Song, In-Ja; Ito, Takuro; Ochiai, Toshinori; Kanno, Akira; Kameya, Toshiaki; Maki, Masayuki

    2005-01-01

    Background Nuclear genes determine the vast range of phenotypes that are responsible for the adaptive abilities of organisms in nature. Nevertheless, the evolutionary processes that generate the structures and functions of nuclear genes are only now be coming understood. The aim of our study is to isolate the alcohol dehydrogenase (Adh) genes in two distantly related legumes, and use these sequences to examine the molecular evolutionary history of this nuclear gene. Results We isolated the expressed Adh genes from two species of legumes, Sophora flavescens Ait. and Wisteria floribunda DC., by a RT-PCR based approach and found a new Adh locus in addition to homologues of the Adh genes found previously in legumes. To examine the evolution of these genes, we compared the species and gene trees and found gene duplication of the Adh loci in the legumes occurred as an ancient event. Conclusion This is the first report revealing that some legume species have at least two Adh gene loci belonging to separate clades. Phylogenetic analyses suggest that these genes resulted from relatively ancient duplication events. PMID:15836788

  17. Alcohol dehydrogenase gene ADH3 activates glucose alcoholic fermentation in genetically engineered Dekkera bruxellensis yeast.

    Science.gov (United States)

    Schifferdecker, Anna Judith; Siurkus, Juozas; Andersen, Mikael Rørdam; Joerck-Ramberg, Dorte; Ling, Zhihao; Zhou, Nerve; Blevins, James E; Sibirny, Andriy A; Piškur, Jure; Ishchuk, Olena P

    2016-04-01

    Dekkera bruxellensis is a non-conventional Crabtree-positive yeast with a good ethanol production capability. Compared to Saccharomyces cerevisiae, its tolerance to acidic pH and its utilization of alternative carbon sources make it a promising organism for producing biofuel. In this study, we developed an auxotrophic transformation system and an expression vector, which enabled the manipulation of D. bruxellensis, thereby improving its fermentative performance. Its gene ADH3, coding for alcohol dehydrogenase, was cloned and overexpressed under the control of the strong and constitutive promoter TEF1. Our recombinant D. bruxellensis strain displayed 1.4 and 1.7 times faster specific glucose consumption rate during aerobic and anaerobic glucose fermentations, respectively; it yielded 1.2 times and 1.5 times more ethanol than did the parental strain under aerobic and anaerobic conditions, respectively. The overexpression of ADH3 in D. bruxellensis also reduced the inhibition of fermentation by anaerobiosis, the "Custer effect". Thus, the fermentative capacity of D. bruxellensis could be further improved by metabolic engineering.

  18. 15-Hydroxyprostaglandin dehydrogenase inactivation as a mechanism of resistance to celecoxib chemoprevention of colon tumors.

    LENUS (Irish Health Repository)

    Yan, Min

    2009-06-09

    Pharmacologic inhibitors of the prostaglandin-synthesizing COX-2 oncogene prevent the development of premalignant human colon adenomas. However, resistance to treatment is common. In this study, we show that the adenoma prevention activity of the COX-2 inhibitor celecoxib requires the concomitant presence of the 15-hydroxyprostaglandin dehydrogenase (15-PGDH) tumor suppressor gene, and that loss of 15-PGDH expression imparts resistance to celecoxib\\'s anti-tumor effects. We first demonstrate that the adenoma-preventive activity of celecoxib is abrogated in mice genetically lacking 15-PGDH. In FVB mice, celecoxib prevents 85% of azoxymethane-induced tumors >1 mm in size, but is essentially inactive in preventing tumor induction in 15-PGDH-null animals. Indeed, celecoxib treated 15-PGDH null animals develop more tumors than do celecoxib naive WT mice. In parallel with the loss of tumor prevention activity, celecoxib-mediated suppression of colonic PGE(2) levels is also markedly attenuated in 15-PGDH-null versus WT mice. Finally, as predicted by the murine models, humans with low colonic 15-PGDH levels also exhibit celecoxib resistance. Specifically, in a colon adenoma prevention trial, in all cases tested, individuals who developed new adenomas while receiving celecoxib treatment were also found as having low colonic 15-PGDH levels.

  19. Chemosensitivity of MCF-7 cells to eugenol: release of cytochrome-c and lactate dehydrogenase

    Science.gov (United States)

    Al Wafai, Rana; El-Rabih, Warde; Katerji, Meghri; Safi, Remi; El Sabban, Marwan; El-Rifai, Omar; Usta, Julnar

    2017-01-01

    Phytochemicals have been extensively researched for their potential anticancer effects. In previous study, direct exposure of rat liver mitochondria to eugenol main ingredient of clove, uncoupled mitochondria and increased F0F1ATPase activity. In the present study, we further investigated the effects of eugenol on MCF-7 cells in culture. Eugenol demonstrated: a dose-dependent decrease in viability (MTT assay), and proliferation (real time cell analysis) of MCF-7 cells, (EC50: 0.9 mM); an increase in reactive oxygen species; a decrease in ATP level and mitochondrial membrane potential (MitoPT JC-1 assay); and a release of cytochrome-c and lactate dehydrogenase (Cytotoxicity Detection Kit PLUS) into culture media at eugenol concentration >EC50. Pretreatment with the antioxidants Trolox and N-acetyl cysteine partially restored cell viability and decreased ROS, with Trolox being more potent. Expression levels of both anti- and pro-apoptotic markers (Bcl-2 and Bax, respectively) decreased with increasing eugenol concentration, with no variation in their relative ratios. Eugenol-treated MCF-7 cells overexpressing Bcl-2 exhibited results similar to those of MCF-7. Our findings indicate that eugenol toxicity is non-apoptotic Bcl-2 independent, affecting mitochondrial function and plasma membrane integrity with no effect on migration or invasion. We report here the chemo-sensitivity of MCF-7 cells to eugenol, a phytochemical with anticancer potential. PMID:28272477

  20. KR-62980 suppresses lipid metabolism through inhibition of cytosolic NADP isocitrate dehydrogenase in zebrafish.

    Science.gov (United States)

    Chun, Hang-Suk; Shin, Sun Hye; Ahn, Sunjoo; Shin, Dae-Seop; Choi, Sun-Sil; Ahn, Jin Hee; Bae, Myung Ae

    2014-04-01

    Peroxisome proliferator-activated receptor γ (PPARγ) is a target of antidiabetic drugs. However, many PPARγ activators, including rosiglitazone, show unwanted side effects, such as weight gain. The KR-62980 [1-(trans-methylimino-N-oxy)-3-phenyl-6-(3-phenylpropoxy)-1H-indene-2-carboxylic acid ethyl ester], a novel partial agonist of PPARγ, is a new compound for diabetes with antihyperglycemic activity and weak antiadipogenic activity. This study was performed to elucidate the mechanism of the weak adipogenesis induced by KR-62980 despite its being a PPARγ agonist in zebrafish. We elucidated the mechanism of KR-62980 in lipid metabolism using adipocytes and zebrafish. Since NADPH is a critical cofactor in fat metabolism, we investigated effect of KR-62980 on NADPH-producing enzymes such as cytosolic NADP(+) isocitrate dehydrogenase (cICDH). We found that the mRNA expression of cICDH was significantly decreased by KR-62980 in 3T3-L1 cells. KR-62980 inhibited lipase activity and lipid metabolism in zebrafish. Further, KR-62980 substantially suppressed cICDH in adipocytes and zebrafish. These results suggest that cICDH may be one of the targets of KR-62980 responsible for weight gain and adipogenesis.

  1. Sulfoacetate released during the assimilation of taurine-nitrogen by Neptuniibacter caesariensis: purification of sulfoacetaldehyde dehydrogenase.

    Science.gov (United States)

    Krejcík, Zdenĕk; Denger, Karin; Weinitschke, Sonja; Hollemeyer, Klaus; Paces, Václav; Cook, Alasdair M; Smits, Theo H M

    2008-08-01

    Taurine (2-aminoethanesulfonate) is a widespread natural product whose nitrogen moiety was recently shown to be assimilated by bacteria, usually with excretion of an organosulfonate via undefined novel pathways; other data involve transcriptional regulator TauR in taurine metabolism. A screen of genome sequences for TauR with the BLAST algorithm allowed the hypothesis that the marine gammaproteobacterium Neptuniibacter caesariensis MED92 would inducibly assimilate taurine-nitrogen and excrete sulfoacetate. The pathway involved an ABC transporter (TauABC), taurine:pyruvate aminotransferase (Tpa), a novel sulfoacetaldehyde dehydrogenase (SafD) and exporter(s) of sulfoacetate (SafE) (DUF81). Ten candidate genes in two clusters involved three sets of paralogues (for TauR, Tpa and SafE). Inducible Tpa and SafD were detected in cell extracts. SafD was purified 600-fold to homogeneity in two steps. The monomer had a molecular mass of 50 kDa (SDS-PAGE); data from gel filtration chromatography indicated a tetrameric native protein. SafD was specific for sulfoacetaldehyde with a K (m)-value of 0.12 mM. The N-terminal amino acid sequence of SafD confirmed the identity of the safD gene. The eight pathway genes were transcribed inducibly, which indicated expression of the whole hypothetical pathway. We presume that this pathway is one source of sulfoacetate in nature, where this compound is dissimilated by many bacteria.

  2. Alternative splicing of testis-specific lactate dehydrogenase C gene in mammals and pigeon.

    Science.gov (United States)

    Huang, Lin; Lin, Yaqiu; Jin, Suyu; Liu, Wei; Xu, Yaou; Zheng, Yucai

    2012-04-01

    The objective of the present study was to confirm the widespread existence of alternative splicing of lactate dehydrogenase c (ldhc) gene in mammals. RT-PCR was employed to amplify cDNAs of ldhc from testes of mammals including pig, dog, rabbit, cat, rat, and mouse, as well as pigeon. Two to six kinds of splice variants of ldhc were observed in the seven species as a result of deletion of one or more exons or insertion of partial sequence of an intron in the mature mRNA. The deleted exons occur mostly in exons 5, 4, 6, and 3. The insertion of a partial sequence of introns, which resulted in an abnormal stop codon in the inserted intron sequence, was observed only in dog and rat. The deletion of exons also resulted in a reading frame shift and formation of a stop codon in some variants. No alternative splicing was observed for ldha and ldhb genes in testis of yak. Native polyacrylamide gel electrophoresis and Western blot analysis revealed no obvious LDH-C4 activity derived from expressed ldhc variants. Our results demonstrated the widespread and unique existence of alternative splicing of ldhc genes in mammals.

  3. Arabidopsis mutant analysis and gene regulation define a nonredundant role for glutamate dehydrogenase in nitrogen assimilation.

    Science.gov (United States)

    Melo-Oliveira, R; Oliveira, I C; Coruzzi, G M

    1996-05-14

    Glutamate dehydrogenase (GDH) is ubiquitous to all organisms, yet its role in higher plants remains enigmatic. To better understand the role of GDH in plant nitrogen metabolism, we have characterized an Arabidopsis mutant (gdh1-1) defective in one of two GDH gene products and have studied GDH1 gene expression. GDH1 mRNA accumulates to highest levels in dark-adapted or sucrose-starved plants, and light or sucrose treatment each repress GDH1 mRNA accumulation. These results suggest that the GDH1 gene product functions in the direction of glutamate catabolism under carbon-limiting conditions. Low levels of GDH1 mRNA present in leaves of light-grown plants can be induced by exogenously supplied ammonia. Under such conditions of carbon and ammonia excess, GDH1 may function in the direction of glutamate biosynthesis. The Arabidopsis gdh-deficient mutant allele gdh1-1 cosegregates with the GDH1 gene and behaves as a recessive mutation. The gdh1-1 mutant displays a conditional phenotype in that seedling growth is specifically retarded on media containing exogenously supplied inorganic nitrogen. These results suggest that GDH1 plays a nonredundant role in ammonia assimilation under conditions of inorganic nitrogen excess. This notion is further supported by the fact that the levels of mRNA for GDH1 and chloroplastic glutamine synthetase (GS2) are reciprocally regulated by light.

  4. Novel non-steroidal inhibitors of human 11beta-hydroxysteroid dehydrogenase type 1.

    Science.gov (United States)

    Vicker, Nigel; Su, Xiangdong; Ganeshapillai, Dharshini; Smith, Andrew; Purohit, Atul; Reed, Michael J; Potter, Barry V L

    2007-05-01

    11beta-Hydroxysteroid dehydrogenase type 1 (11beta-HSD1) regulates glucocorticoid action at the pre-receptor stage by converting cortisone to cortisol. 11beta-HSD1 is selectively expressed in many tissues including the liver and adipose tissue where metabolic events are important. Metabolic syndrome relates to a number of metabolic abnormalities and currently has a prevalence of >20% in adult Americans. 11beta-HSD1 inhibitors are being investigated by many major pharmaceutical companies for type 2 diabetes and other abnormalities associated with metabolic syndrome. In this area of intense interest a number of structural types of 11beta-HSD1 inhibitor have been identified. It is important to have an array of structural types as the physicochemical properties of the compounds will determine tissue distribution, HPA effects, and ultimately clinical utility. Here we report the discovery and synthesis of three structurally different series of novel 11beta-HSD1 inhibitors that inhibit human 11beta-HSD1 in the low micromolar range. Docking studies with 1-3 into the crystal structure of human 11beta-HSD1 reveal how the molecules may interact with the enzyme and cofactor and give further scope for structure based drug design in the optimisation of these series.

  5. The design of novel 17beta-hydroxysteroid dehydrogenase type 3 inhibitors.

    Science.gov (United States)

    Vicker, Nigel; Sharland, Christopher M; Heaton, Wesley B; Gonzalez, Ana M Ramos; Bailey, Helen V; Smith, Andrew; Springall, Jeremy S; Day, Joanna M; Tutill, Helena J; Reed, Michael J; Purohit, Atul; Potter, Barry V L

    2009-03-25

    17beta-Hydroxysteroid dehydrogenase type 3 (17beta-HSD3) is expressed at high levels in the testes and seminal vesicles but has also been shown to be present in prostate tissue, suggesting its potential involvement in both gonadal and non-gonadal testosterone biosynthesis. The role of 17beta-HSD3 in testosterone biosynthesis makes this enzyme an attractive molecular target for small molecule inhibitors for the treatment of prostate cancer. Here we report the design of selective inhibitors of 17beta-HSD3 as potential anti-cancer agents. Due to 17beta-HSD3 being a membrane-bound protein a crystal structure is not yet available. A homology model of 17beta-HSD3 has been built to aid structure-based drug design. This model has been used with docking studies to identify a series of lead compounds that may give an insight as to how inhibitors interact with the active site. Compound 1 was identified as a potent selective inhibitor of 17beta-HSD3 with an IC(50)=700nM resulting in the discovery of a novel lead series for further optimisation. Using our homology model as a tool for inhibitor design compound 5 was discovered as a novel potent and selective inhibitor of 17beta-HSD3 with an IC(50) approximately 200nM.

  6. NAD-dependent isocitrate dehydrogenase as a novel target of tributyltin in human embryonic carcinoma cells

    Science.gov (United States)

    Yamada, Shigeru; Kotake, Yaichiro; Demizu, Yosuke; Kurihara, Masaaki; Sekino, Yuko; Kanda, Yasunari

    2014-08-01

    Tributyltin (TBT) is known to cause developmental defects as endocrine disruptive chemicals (EDCs). At nanomoler concentrations, TBT actions were mediated by genomic pathways via PPAR/RXR. However, non-genomic target of TBT has not been elucidated. To investigate non-genomic TBT targets, we performed comprehensive metabolomic analyses using human embryonic carcinoma NT2/D1 cells. We found that 100 nM TBT reduced the amounts of α-ketoglutarate, succinate and malate. We further found that TBT decreased the activity of NAD-dependent isocitrate dehydrogenase (NAD-IDH), which catalyzes the conversion of isocitrate to α-ketoglutarate in the TCA cycle. In addition, TBT inhibited cell growth and enhanced neuronal differentiation through NAD-IDH inhibition. Furthermore, studies using bacterially expressed human NAD-IDH and in silico simulations suggest that TBT inhibits NAD-IDH due to a possible interaction. These results suggest that NAD-IDH is a novel non-genomic target of TBT at nanomolar levels. Thus, a metabolomic approach may provide new insights into the mechanism of EDC action.

  7. Photoactivation of Mutant Isocitrate Dehydrogenase 2 Reveals Rapid Cancer-Associated Metabolic and Epigenetic Changes.

    Science.gov (United States)

    Walker, Olivia S; Elsässer, Simon J; Mahesh, Mohan; Bachman, Martin; Balasubramanian, Shankar; Chin, Jason W

    2016-01-27

    Isocitrate dehydrogenase is mutated at a key active site arginine residue (Arg172 in IDH2) in many cancers, leading to the synthesis of the oncometabolite (R)-2-hydroxyglutarate (2HG). To investigate the early events following acquisition of this mutation in mammalian cells we created a photoactivatable version of IDH2(R172K), in which K172 is replaced with a photocaged lysine (PCK), via genetic code expansion. Illumination of cells expressing this mutant protein led to a rapid increase in the levels of 2HG, with 2HG levels reaching those measured in patient tumor samples, within 8 h. 2HG accumulation is closely followed by a global decrease in 5-hydroxymethylcytosine (5-hmC) in DNA, demonstrating that perturbations in epigenetic DNA base modifications are an early consequence of mutant IDH2 in cells. Our results provide a paradigm for rapidly and synchronously uncloaking diverse oncogenic mutations in live cells to reveal the sequence of events through which they may ultimately cause transformation.

  8. Plastidial NAD-dependent malate dehydrogenase is critical for embryo development and heterotrophic metabolism in Arabidopsis.

    Science.gov (United States)

    Beeler, Seraina; Liu, Hung-Chi; Stadler, Martha; Schreier, Tina; Eicke, Simona; Lue, Wei-Ling; Truernit, Elisabeth; Zeeman, Samuel C; Chen, Jychian; Kötting, Oliver

    2014-03-01

    In illuminated chloroplasts, one mechanism involved in reduction-oxidation (redox) homeostasis is the malate-oxaloacetate (OAA) shuttle. Excess electrons from photosynthetic electron transport in the form of nicotinamide adenine dinucleotide phosphate, reduced are used by NADP-dependent malate dehydrogenase (MDH) to reduce OAA to malate, thus regenerating the electron acceptor NADP. NADP-MDH is a strictly redox-regulated, light-activated enzyme that is inactive in the dark. In the dark or in nonphotosynthetic tissues, the malate-OAA shuttle was proposed to be mediated by the constitutively active plastidial NAD-specific MDH isoform (pdNAD-MDH), but evidence is scarce. Here, we reveal the critical role of pdNAD-MDH in Arabidopsis (Arabidopsis thaliana) plants. A pdnad-mdh null mutation is embryo lethal. Plants with reduced pdNAD-MDH levels by means of artificial microRNA (miR-mdh-1) are viable, but dark metabolism is altered as reflected by increased nighttime malate, starch, and glutathione levels and a reduced respiration rate. In addition, miR-mdh-1 plants exhibit strong pleiotropic effects, including dwarfism, reductions in chlorophyll levels, photosynthetic rate, and daytime carbohydrate levels, and disordered chloroplast ultrastructure, particularly in developing leaves, compared with the wild type. pdNAD-MDH deficiency in miR-mdh-1 can be functionally complemented by expression of a microRNA-insensitive pdNAD-MDH but not NADP-MDH, confirming distinct roles for NAD- and NADP-linked redox homeostasis.

  9. Lactate dehydrogenase B is associated with the response to neoadjuvant chemotherapy in oral squamous cell carcinoma.

    Directory of Open Access Journals (Sweden)

    Wenyi Sun

    Full Text Available Oral squamous cell carcinoma (OSCC comprises a subset of head and neck squamous cell carcinoma (HNSCC with poor therapeutic outcomes and high glycolytic dependency. Neoadjuvant chemotherapy regimens of docetaxel, cisplatin and 5-fluorouracil (TPF are currently accepted as standard regimens for HNSCC patients with a high risk of distant metastatic spread. However, the antitumor outcomes of TPF neoadjuvant chemotherapy in HNSCC remain controversial. This study investigated the role of lactate dehydrogenase B (LDHB, a key glycolytic enzyme catalyzing the inter-conversion between pyruvate and lactate, in determining chemotherapy response and prognosis in OSCC patients. We discovered that a high protein level of LDHB in OSCC patients was associated with a poor response to TPF regimen chemotherapy as well as poor overall survival and disease-free survival. Our in-depth study revealed that high LDHB expression conferred resistance to taxol but not 5-fluorouracil or cisplatin. LDHB deletion sensitized OSCC cell lines to taxol, whereas the introduction of LDHB decreased sensitivity to taxol treatment. Taxol induced a pronounced impact on LDHB-down-regulated OSCC cells in terms of apoptosis, G2/M phase cell cycle arrest and energy metabolism. In conclusion, our study highlighted the critical role of LDHB in OSCC and proposed that LDHB could be used as a biomarker for the stratification of patients for TPF neoadjuvant chemotherapy and the determination of prognosis in OSCC patients.

  10. Sequestration of Glyceraldehyde-3-phosphate Dehydrogenase to Aggregates Formed by Mutant Huntingtin

    Institute of Scientific and Technical Information of China (English)

    Junchao WU; Fang LIN; Zhenghong QIN

    2007-01-01

    Glyceraldehyde-3-phosphate dehydrogenase (GAPDH) has been reported to interact with proteins containing the polyglutamine (polyQ) domain. The present study was undertaken to evaluate the potential contributions of the polyQ and polyproline (polyP) domains to the co-localization of mutant huntingtin (htt) and GAPDH. Overexpression of N-terminal htt (1-969 amino acids) with 100Q and 46Q (htt1-969-100Q and httl-969-46Q, mutant htt) in human mammary gland carcinoma MCF-7 cells formed more htt aggregates than that of htt1-969-18Q (wild-type htt). The co-localization of GAPDH with htt aggregates was found in the cells expressing mutant but not wild-type htt. Deletion of the polyp region in the N-terminal htt had no effect on the co-localization of GAPDH and mutant htt aggregates. These results suggest that the polyQ domain, but not the polyp domain, plays a role in the sequestration of GAPDH to aggregates by mutant htt. This effect might contribute to the dysfunction of neurons caused by mutant htt in Huntington's disease.

  11. Green Tea Polyphenols Control Dysregulated Glutamate Dehydrogenase in Transgenic Mice by Hijacking the ADP Activation Site

    Energy Technology Data Exchange (ETDEWEB)

    Li, Changhong; Li, Ming; Chen, Pan; Narayan, Srinivas; Matschinsky, Franz M.; Bennett, Michael J.; Stanley, Charles A.; Smith, Thomas J. (CH-PA); (UPENN); (Danforth)

    2012-05-09

    Glutamate dehydrogenase (GDH) catalyzes the oxidative deamination of L-glutamate and, in animals, is extensively regulated by a number of metabolites. Gain of function mutations in GDH that abrogate GTP inhibition cause the hyperinsulinism/hyperammonemia syndrome (HHS), resulting in increased pancreatic {beta}-cell responsiveness to leucine and susceptibility to hypoglycemia following high protein meals. We have previously shown that two of the polyphenols from green tea (epigallocatechin gallate (EGCG) and epicatechin gallate (ECG)) inhibit GDH in vitro and that EGCG blocks GDH-mediated insulin secretion in wild type rat islets. Using structural and site-directed mutagenesis studies, we demonstrate that ECG binds to the same site as the allosteric regulator, ADP. Perifusion assays using pancreatic islets from transgenic mice expressing a human HHS form of GDH demonstrate that the hyperresponse to glutamine caused by dysregulated GDH is blocked by the addition of EGCG. As observed in HHS patients, these transgenic mice are hypersensitive to amino acid feeding, and this is abrogated by oral administration of EGCG prior to challenge. Finally, the low basal blood glucose level in the HHS mouse model is improved upon chronic administration of EGCG. These results suggest that this common natural product or some derivative thereof may prove useful in controlling this genetic disorder. Of broader clinical implication is that other groups have shown that restriction of glutamine catabolism via these GDH inhibitors can be useful in treating various tumors. This HHS transgenic mouse model offers a highly useful means to test these agents in vivo.

  12. Regulation of human cerebrospinal fluid malate dehydrogenase 1 in sporadic Creutzfeldt-Jakob disease patients

    Science.gov (United States)

    Schmitz, Matthias; Llorens, Franc; Pracht, Alexander; Thom, Tobias; Correia, Ângela; Zafar, Saima; Ferrer, Isidre; Zerr, Inga

    2016-01-01

    The identification of reliable diagnostic biomarkers in differential diagnosis of neurodegenerative diseases is an ongoing topic. A previous two-dimensional proteomic study on cerebrospinal fluid (CSF) revealed an elevated level of an enzyme, mitochondrial malate dehydrogenase 1 (MDH1), in sporadic Creutzfeldt-Jakob disease (sCJD) patients. Here, we could demonstrate the expression of MDH1 in neurons as well as in the neuropil. Its levels are lower in sCJD brains than in control brains. An examination of CSF-MDH1 in sCJD patients by ELISA revealed a significant elevation of CSF-MDH1 levels in sCJD patients (independently from the PRNP codon 129 MV genotype or the prion protein scrapie (PrPSc) type) in comparison to controls. In combination with total tau (tau), CSF-MDH1 detection exhibited a high diagnostic accuracy for sCJD diagnosis with a sensitivity of 97.5% and a specificity of 95.6%. A correlation study of MDH1 level in CSF with other neurodegenerative marker proteins revealed a significant positive correlation between MDH1 concentration with tau, 14-3-3 and neuron specific enolase level. In conclusion, our study indicated the potential of MDH1 in combination with tau as an additional biomarker in sCJD improving diagnostic accuracy of tau markedly. PMID:27852982

  13. Sorbitol dehydrogenase is a cytosolic protein required for sorbitol metabolism in Arabidopsis thaliana.

    Science.gov (United States)

    Aguayo, María Francisca; Ampuero, Diego; Mandujano, Patricio; Parada, Roberto; Muñoz, Rodrigo; Gallart, Marta; Altabella, Teresa; Cabrera, Ricardo; Stange, Claudia; Handford, Michael

    2013-05-01

    Sorbitol is converted to fructose in Rosaceae species by SORBITOL DEHYDROGENASE (SDH, EC 1.1.1.14), especially in sink organs. SDH has also been found in non-Rosaceae species and here we show that the protein encoded by At5g51970 in Arabidopsis thaliana (L.) Heynh. possesses the molecular characteristics of an SDH. Using a green fluorescent protein-tagged version and anti-SDH antisera, we determined that SDH is cytosolically localized, consistent with bioinformatic predictions. We also show that SDH is widely expressed, and that SDH protein accumulates in both source and sink organs. In the presence of NAD+, recombinant SDH exhibited greatest oxidative activity with sorbitol, ribitol and xylitol as substrates; other sugar alcohols were oxidized to a lesser extent. Under standard growth conditions, three independent sdh- mutants developed as wild-type. Nevertheless, all three exhibited reduced dry weight and primary root length compared to wild-type when grown in the presence of sorbitol. Additionally, under short-day conditions, the mutants were more resistant to dehydration stress, as shown by a reduced loss of leaf water content when watering was withheld, and a greater survival rate on re-watering. This evidence suggests that limitations in the metabolism of sugar alcohols alter the growth of Arabidopsis and its response to drought.

  14. Green tea polyphenols control dysregulated glutamate dehydrogenase in transgenic mice by hijacking the ADP activation site.

    Science.gov (United States)

    Li, Changhong; Li, Ming; Chen, Pan; Narayan, Srinivas; Matschinsky, Franz M; Bennett, Michael J; Stanley, Charles A; Smith, Thomas J

    2011-09-30

    Glutamate dehydrogenase (GDH) catalyzes the oxidative deamination of L-glutamate and, in animals, is extensively regulated by a number of metabolites. Gain of function mutations in GDH that abrogate GTP inhibition cause the hyperinsulinism/hyperammonemia syndrome (HHS), resulting in increased pancreatic β-cell responsiveness to leucine and susceptibility to hypoglycemia following high protein meals. We have previously shown that two of the polyphenols from green tea (epigallocatechin gallate (EGCG) and epicatechin gallate (ECG)) inhibit GDH in vitro and that EGCG blocks GDH-mediated insulin secretion in wild type rat islets. Using structural and site-directed mutagenesis studies, we demonstrate that ECG binds to the same site as the allosteric regulator, ADP. Perifusion assays using pancreatic islets from transgenic mice expressing a human HHS form of GDH demonstrate that the hyperresponse to glutamine caused by dysregulated GDH is blocked by the addition of EGCG. As observed in HHS patients, these transgenic mice are hypersensitive to amino acid feeding, and this is abrogated by oral administration of EGCG prior to challenge. Finally, the low basal blood glucose level in the HHS mouse model is improved upon chronic administration of EGCG. These results suggest that this common natural product or some derivative thereof may prove useful in controlling this genetic disorder. Of broader clinical implication is that other groups have shown that restriction of glutamine catabolism via these GDH inhibitors can be useful in treating various tumors. This HHS transgenic mouse model offers a highly useful means to test these agents in vivo.

  15. Subcellular localization and vacuolar targeting of sorbitol dehydrogenase in apple seed.

    Science.gov (United States)

    Wang, Xiu-Ling; Hu, Zi-Ying; You, Chun-Xiang; Kong, Xiu-Zhen; Shi, Xiao-Pu

    2013-09-01

    Sorbitol is the primary photosynthate and translocated carbohydrate in fruit trees of the Rosaceae family. NAD(+)-dependent sorbitol dehydrogenase (NAD-SDH, EC 1.1.1.14), which mainly catalyzes the oxidation of sorbitol to fructose, plays a key role in regulating sink strength in apple. In this study, we found that apple NAD-SDH was ubiquitously distributed in epidermis, parenchyma, and vascular bundle in developing cotyledon. NAD-SDH was localized in the cytosol, the membranes of endoplasmic reticulum and vesicles, and the vacuolar lumen in the cotyledon at the middle stage of seed development. In contrast, NAD-SDH was mainly distributed in the protein storage vacuoles in cotyledon at the late stage of seed development. Sequence analysis revealed there is a putative signal peptide (SP), also being predicated to be a transmembrane domain, in the middle of proteins of apple NAD-SDH isoforms. To investigate whether the putative internal SP functions in the vacuolar targeting of NAD-SDH, we analyzed the localization of the SP-deletion mutants of MdSDH5 and MdSDH6 (two NAD-SDH isoforms in apple) by the transient expression system in Arabidopsis protoplasts. MdSDH5 and MdSDH6 were not localized in the vacuoles after their SPs were deleted, suggesting the internal SP functions in the vacuolar targeting of apple NAD-SDH.

  16. The glyceraldehyde-3-phosphate dehydrogenase and the small GTPase Rab 2 are crucial for Brucella replication.

    Directory of Open Access Journals (Sweden)

    Emilie Fugier

    2009-06-01

    Full Text Available The intracellular pathogen Brucella abortus survives and replicates inside host cells within an endoplasmic reticulum (ER-derived replicative organelle named the "Brucella-containing vacuole" (BCV. Here, we developed a subcellular fractionation method to isolate BCVs and characterize for the first time the protein composition of its replicative niche. After identification of BCV membrane proteins by 2 dimensional (2D gel electrophoresis and mass spectrometry, we focused on two eukaryotic proteins: the glyceraldehyde-3-phosphate dehydrogenase (GAPDH and the small GTPase Rab 2 recruited to the vacuolar membrane of Brucella. These proteins were previously described to localize on vesicular and tubular clusters (VTC and to regulate the VTC membrane traffic between the endoplasmic reticulum (ER and the Golgi. Inhibition of either GAPDH or Rab 2 expression by small interfering RNA strongly inhibited B. abortus replication. Consistent with this result, inhibition of other partners of GAPDH and Rab 2, such as COPI and PKC iota, reduced B. abortus replication. Furthermore, blockage of Rab 2 GTPase in a GDP-locked form also inhibited B. abortus replication. Bacteria did not fuse with the ER and instead remained in lysosomal-associated membrane vacuoles. These results reveal an essential role for GAPDH and the small GTPase Rab 2 in B. abortus virulence within host cells.

  17. Contribution of haemolysis to jaundice in Sephardic Jewish glucose-6-phosphate dehydrogenase deficient neonates.

    Science.gov (United States)

    Kaplan, M; Vreman, H J; Hammerman, C; Leiter, C; Abramov, A; Stevenson, D K

    1996-06-01

    We determined the contribution of haemolysis to the development of hyperbilirubinaemia in glucose-6-phosphate dehydrogenase (G-6-PD) deficient neonates and G-6-PD normal controls. Blood carboxyhaemoglobin (COHb), sampled on the third day of life, was measured by gas chromatography, corrected for inhaled carbon monoxide (COHbC), and expressed as a percentage of total haemoglobin concentration (Hb). Serum bilirubin was tested as clinically necessary. 37 non-jaundiced (peak serum total bilirubin (PSTB) or = 257 mumol/l) G-6-PD-deficient neonates were compared to 31 non-jaundiced and 24 jaundiced controls with comparable PSTB values, respectively. COHbC values for the entire G-6-PD deficient group were higher than in the controls (0.75 +/- 0.17% v 0.62 +/- 0.19%, P 0.05) but did in the controls (r = 0.58, P < 0.001). COHbC values were increased to a similar extent in the G-6-PD-deficient, non-jaundiced (0.72 +/- 0.16%), the G-6-PD-deficient, jaundiced (0.80 +/- 0.19%) and the control, jaundiced (0.75 +/- 0.18%) subgroups, compared to the control, non-jaundiced subgroup (0.53 +/- 0.13%) (P < 0.05). Although present in G-6-PD deficient neonates, increased haemolysis was not directly related to the PSTB.

  18. An atypical distribution of lactate dehydrogenase isoenzymes in the hooded seal (Cystophora cristata) brain may reflect a biochemical adaptation to diving.

    Science.gov (United States)

    Hoff, Mariana Leivas Müller; Fabrizius, Andrej; Folkow, Lars P; Burmester, Thorsten

    2016-04-01

    The brains of some diving mammals can withstand periods of severe hypoxia without signs of deleterious effects. This may in part be due to an enhanced cerebral capacity for anaerobic energy production. Here, we have tested this hypothesis by comparing various parameters of the lactate dehydrogenase (LDH) in the brain of the hooded seal (Cystophora cristata) with those in the brains of the ferret (Mustela putorius furo) and mouse (Mus musculus). We found that mRNA and protein expression of lactate dehydrogenase a (LDHA) and lactate dehydrogenase b (LDHB), and also the LDH activity were significantly higher in the ferret brain than in brains of the hooded seal and the mouse (p diving mammals. Moreover, immunofluorescence studies showed more pronounced co-localization of LDHB and glial fibrillary acidic protein in the cortex of the hooded seal. Since LDHB isoenzymes primarily catalyze the conversion of lactate to pyruvate, this finding suggests that the contribution of astrocytes to the brain aerobic metabolism is higher in the hooded seal than in non-diving species. The cerebral tolerance of the hooded seal to hypoxia may therefore partly rely on different LDH isoenzymes distribution.