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Sample records for oral farnesyl transferase

  1. A phase II trial of R115777, an oral farnesyl transferase inhibitor, in      patients with advanced urothelial tract transitional cell carcinoma

    DEFF Research Database (Denmark)

    Rosenberg, Jonathan E.; Maase, Hans von der; Seigne, John D.;

    2005-01-01

    BACKGROUND: R115777 is a potent farnesyl transferase inhibitor and has       significant antitumor effects in vitro and in vivo. METHODS: The objective       of the current study was to determine the objective response proportion in       patients with metastatic transitional cell carcinoma (TCC......) of the       urothelial tract who received treatment with R115777 at a dose of 300 mg       orally given twice daily for 21 days followed by 7 days of rest for every       4-week cycle. Thirty-four patients with TCC were enrolled in this Phase II       study. Patients were allowed to have received a maximum of one prior......       observed. CONCLUSIONS: The objective response rate of R115777 was not       sufficient to warrant future investigation in TCC as a single agent.       Preliminary evidence of the activity of R115777 in 2 chemotherapy-naive       patients may warrant further investigation in combination with first...

  2. A phase II trial of R115777, an oral farnesyl transferase inhibitor, in      patients with advanced urothelial tract transitional cell carcinoma

    DEFF Research Database (Denmark)

    Rosenberg, Jonathan E.; Maase, Hans von der; Seigne, John D.

    2005-01-01

    BACKGROUND: R115777 is a potent farnesyl transferase inhibitor and has       significant antitumor effects in vitro and in vivo. METHODS: The objective       of the current study was to determine the objective response proportion in       patients with metastatic transitional cell carcinoma (TCC......) of the       urothelial tract who received treatment with R115777 at a dose of 300 mg       orally given twice daily for 21 days followed by 7 days of rest for every       4-week cycle. Thirty-four patients with TCC were enrolled in this Phase II       study. Patients were allowed to have received a maximum of one prior......       observed. CONCLUSIONS: The objective response rate of R115777 was not       sufficient to warrant future investigation in TCC as a single agent.       Preliminary evidence of the activity of R115777 in 2 chemotherapy-naive       patients may warrant further investigation in combination with first...

  3. Synthesis and evaluation of a novel series of farnesyl protein transferase inhibitors as non-peptidic CAAX tetrapeptide analogues.

    Science.gov (United States)

    Perez, Michel; Maraval, Catherine; Dumond, Stephan; Lamothe, Marie; Schambel, Philippe; Etiévant, Chantal; Hill, Bridget

    2003-04-17

    A novel series of compounds, derived from 4-amino-phenyl piperazine, has been designed to selectively inhibit farnesyl protein transferase (FPTase) as CAAX tetrapeptide analogues. Certain of these compounds were shown to possess low nanomolar inhibitory activity both against the isolated enzyme and in cultured cells.

  4. Novel derivatives of aclacinomycin A block cancer cell migration through inhibition of farnesyl transferase.

    Science.gov (United States)

    Magi, Shigeyuki; Shitara, Tetsuo; Takemoto, Yasushi; Sawada, Masato; Kitagawa, Mitsuhiro; Tashiro, Etsu; Takahashi, Yoshikazu; Imoto, Masaya

    2013-03-01

    In the course of screening for an inhibitor of farnesyl transferase (FTase), we identified two compounds, N-benzyl-aclacinomycin A (ACM) and N-allyl-ACM, which are new derivatives of ACM. N-benzyl-ACM and N-allyl-ACM inhibited FTase activity with IC50 values of 0.86 and 2.93 μM, respectively. Not only ACM but also C-10 epimers of each ACM derivative failed to inhibit FTase. The inhibition of FTase by N-benzyl-ACM and N-allyl-ACM seems to be specific, because these two compounds did not inhibit geranylgeranyltransferase or geranylgeranyl pyrophosphate (GGPP) synthase up to 100 μM. In cultured A431 cells, N-benzyl-ACM and N-allyl-ACM also blocked both the membrane localization of H-Ras and activation of the H-Ras-dependent PI3K/Akt pathway. In addition, they inhibited epidermal growth factor (EGF)-induced migration of A431 cells. Thus, N-benzyl-ACM and N-allyl-ACM inhibited EGF-induced migration of A431 cells by inhibiting the farnesylation of H-Ras and subsequent H-Ras-dependent activation of the PI3K/Akt pathway.

  5. Farnesyl transferase inhibitors induce extended remissions in transgenic mice with mature B cell lymphomas

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    Refaeli Yosef

    2008-05-01

    Full Text Available Abstract Background We have used a mouse model based on overexpression of c-Myc in B cells genetically engineered to be self-reactive to test the hypothesis that farnesyl transferase inhibitors (FTIs can effectively treat mature B cell lymphomas. FTIs are undergoing clinical trials to treat both lymphoid and non-lymphoid malignancies and we wished to obtain evidence to support the inclusion of B cell lymphomas in future trials. Results We report that two FTIs, L-744,832 and SCH66336, blocked the growth of mature B cell lymphoma cells in vitro and in vivo. The FTI treatment affected the proliferation and survival of the transformed B cells to a greater extent than naïve B cells stimulated with antigen. In syngeneic mice transplanted with the transgenic lymphoma cells, L-744,832 treatment prevented the growth of the tumor cells and the morbidity associated with the resulting lymphoma progression. Tumors that arose from transplantation of the lymphoma cells regressed with as little as three days of treatment with L-744,832 or SCH66336. Treatment of these established lymphomas with L-744,832 for seven days led to long-term remission of the disease in approximately 25% of animals. Conclusion FTI treatment can block the proliferation and survival of self-reactive transformed B cells that overexpress Myc. In mice transplanted with mature B cell lymphomas, we found that FTI treatment led to regression of disease. FTIs warrant further consideration as therapeutic agents for mature B cell lymphomas and other lymphoid tumors.

  6. Inhibitors of protein:farnesyl transferase and protein:geranylgeranyl transferase I : Synthesis of homologous diphosphonate analogs of isoprenylated pyrophosphate

    NARCIS (Netherlands)

    Overhand, M.; Stuivenberg, H.R.; Pieterman, E.; Cohen, L.H.; Leeuwen, R.E.W. van; Valentijn, A.R.P.M.; Overkleeft, H.S.; Marel, G.A. van der; Boom, J.H. van

    1998-01-01

    Novel diphosphonate homologs 7a-7c, and their cyclic counterparts 8a- 8c, of the previously synthesized farnesyl pyrophosphate analogs 1 and 2 were prepared and tested for their inhibition potency and specificity of the enzymes PFT and PGGT-I. Compound 2 was shown to be the most potent inhibitor of

  7. Weekly paclitaxel, gemcitabine, and external irradiation followed by randomized farnesyl transferase inhibitor R115777 for locally advanced pancreatic cancer

    Science.gov (United States)

    Rich, Tyvin A; Winter, Kathryn; Safran, Howard; Hoffman, John P; Erickson, Beth; Anne, Pramila R; Myerson, Robert J; Cline-Burkhardt, Vivian JM; Perez, Kimberly; Willett, Christopher

    2012-01-01

    Purpose The Radiation Therapy Oncology Group (RTOG) multi-institutional Phase II study 98-12, evaluating paclitaxel and concurrent radiation (RT) for locally advanced pancreatic cancer, demonstrated a median survival of 11.3 months and a 1-year survival of 43%. The purpose of the randomized Phase II study by RTOG 0020 was to evaluate the addition of weekly low- dose gemcitabine with concurrent paclitaxel/RT and to evaluate the efficacy and safety of the farnesyl transferase inhibitor R115777 following chemoradiation. Patients and methods Patients with unresectable, nonmetastatic adenocarcinoma of the pancreas were eligible. Patients in Arm 1 received gemcitabine, 75 mg/m2/week, and paclitaxel, 40 mg/m2/week, for 6 weeks, with 50.4 Gy radiation (CXRT). Patients in Arm 2 received an identical chemoradiation regimen but then received maintenance R115777, 300 mg twice a day for 21 days every 28 days (CXRT+R115777), until disease progression or unacceptable toxicity. Results One hundred ninety-five patients were entered into this study, and 184 were analyzable. Grade 4 nonhematologic toxicities occurred in less than 5% of CXRT patients. The most common grade 3/4 toxicity from R115777 was myelosuppression; however, grade 3/4 hepatic, metabolic, musculoskeletal, and neurologic toxicities were also reported. The median survival time was 11.5 months and 8.9 months for the CXRT and CXRT+R115777 arms, respectively. Conclusions The CXRT arm achieved a median survival of almost 1-year, supporting chemoradiation as an important therapeutic modality for locally advanced pancreatic cancer. Maintenance R115777 is not effective and is associated with a broad range of toxicities. These findings provide clinical evidence that inhibition of farnesylation affects many metabolic pathways, underscoring the challenge of developing an effective K-ras inhibitor. PMID:22977306

  8. Weekly paclitaxel, gemcitabine, and external irradiation followed by randomized farnesyl transferase inhibitor R115777 for locally advanced pancreatic cancer

    Directory of Open Access Journals (Sweden)

    Rich TA

    2012-08-01

    Full Text Available Tyvin A Rich,1 Kathryn Winter,2 Howard Safran,3 John P Hoffman,4 Beth Erickson,5 Pramila R Anne,6 Robert J Myerson,7 Vivian JM Cline-Burkhardt,8 Kimberly Perez,3 Christopher Willett91The Cancer Center, University of Virginia Health System West, University of Virginia, Charlottesville, VA, USA; 2RTOG Statistical Center, Philadelphia, PA, USA; 3Brown University, Providence, RI, USA; 4Foxchase Cancer Center, Philadelphia, PA, USA; 5Medical College of Wisconsin, Milwaukee, WI, USA; 6Thomas Jefferson University, Philadelphia, PA, USA; 7Washington University, St Louis, MO, USA; 8Comprehensive Cancer Centers of Nevada, Las Vegas, NV, USA; 9Duke University, Durham, NC, USAPurpose: The Radiation Therapy Oncology Group (RTOG multi-institutional Phase II study 98-12, evaluating paclitaxel and concurrent radiation (RT for locally advanced pancreatic cancer, demonstrated a median survival of 11.3 months and a 1-year survival of 43%. The purpose of the randomized Phase II study by RTOG 0020 was to evaluate the addition of weekly low-dose gemcitabine with concurrent paclitaxel/RT and to evaluate the efficacy and safety of the farnesyl transferase inhibitor R115777 following chemoradiation.Patients and methods: Patients with unresectable, nonmetastatic adenocarcinoma of the pancreas were eligible. Patients in Arm 1 received gemcitabine, 75 mg/m2/week, and paclitaxel, 40 mg/m2/week, for 6 weeks, with 50.4 Gy radiation (CXRT. Patients in Arm 2 received an identical chemoradiation regimen but then received maintenance R115777, 300 mg twice a day for 21 days every 28 days (CXRT+R115777, until disease progression or unacceptable toxicity.Results: One hundred ninety-five patients were entered into this study, and 184 were analyzable. Grade 4 nonhematologic toxicities occurred in less than 5% of CXRT patients. The most common grade 3/4 toxicity from R115777 was myelosuppression; however, grade 3/4 hepatic, metabolic, musculoskeletal, and neurologic toxicities were

  9. Targeting farnesyl-transferase as a novel therapeutic strategy for mevalonate kinase deficiency: in vitro and in vivo approaches.

    Science.gov (United States)

    De Leo, Luigina; Marcuzzi, Annalisa; Decorti, Giuliana; Tommasini, Alberto; Crovella, Sergio; Pontillo, Alessandra

    2010-06-01

    Mevalonate kinase deficiency (MKD) is a rare inborn auto-inflammatory disease due to the impairment of the pathway for the biosynthesis of cholesterol and non-sterol isoprenoids. The shortage of isoprenoids compounds and in particular of geranylgeranylpyrophosphate (GGPP) was recently associated to the MKD characteristic inflammatory attacks. The aim of this study is to demonstrate that the normalization of the mevalonate pathway intermediates levels and in particular of GGPP, through the specific inhibition of farnesyl-transferase (FT) with Manumycin A could ameliorate the inflammatory phenotype of MKD patients. The effect of Manumycin A was first evaluated in MKD mouse and cellular models, chemically obtained using the aminobisphosphonate alendronate (ALD), and then in monocytes isolated from 2 MKD patients. Our findings were compared to those obtained by using natural exogenous isoprenoids (NEIs). Manumycin A was able to significantly reduce the inflammatory marker serum amyloid A in ALD-treated Balb/c mice, as well as IL-1 beta secretion in ALD-monocytes and in MKD patients. These results clearly showed that, through the inhibition of FT, an increased number of mevalonate pathway intermediates could be redirected towards the synthesis of GGPP diminishing the inflammatory response. The importance in limiting the shortage of GGPP was emphasized by the anti-inflammatory effect of NEIs that, due to their biochemical structure, can enter the MKD pathway. In conclusion, manumycin A, as well as NEIs, showed anti-inflammatory effect in MKD models and especially in MKD-monocytes, suggesting novel approaches in the treatment of MKD, an orphan disease without any efficacious treatment currently available.

  10. Design, synthesis and evaluation of Novel 1-(Substituted Acetyl-4-(10-Bromo-8-Chloro-5,6-Dihydro-11H-Benzo[5,6]Cyclohepta[1,2-B]Pyridine-11-Ylidenepiperidines as antitumor agents and farnesyl protein transferase inhibitors

    Directory of Open Access Journals (Sweden)

    Gatne P

    2010-01-01

    Full Text Available Eight novel 1-(substituted acetyl-4-(10-bromo-8-chloro-5,6-dihydro-11H-benzo[5,6] cyclohepta [1,2-b] pyridine-11-ylidenepiperidines were designed by incorporating zinc binding groups to enhance activity. The designed molecules were synthesized and were evaluated for antitumor activity in vitro in five cell lines and for farnesyl protein transferase inhibition. Test compounds (6a-h exhibited antitumor activity in most of the cell lines but were less potent than adriamycin. Compound 6e was most active with IC 50 values of <15 μM in two cell lines tested. Test compounds also exhibited potent FPT inhibitory activity and 6c was most potent with IC 50 value of <30 μM.

  11. Drug screening on Hutchinson Gilford progeria pluripotent stem cells reveals aminopyrimidines as new modulators of farnesylation.

    Science.gov (United States)

    Blondel, S; Egesipe, A-L; Picardi, P; Jaskowiak, A-L; Notarnicola, M; Ragot, J; Tournois, J; Le Corf, A; Brinon, B; Poydenot, P; Georges, P; Navarro, C; Pitrez, P R; Ferreira, L; Bollot, G; Bauvais, C; Laustriat, D; Mejat, A; De Sandre-Giovannoli, A; Levy, N; Bifulco, M; Peschanski, M; Nissan, X

    2016-02-18

    Hutchinson-Gilford progeria syndrome (HGPS) is a rare genetic disorder characterized by a dramatic appearance of premature aging. HGPS is due to a single-base substitution in exon 11 of the LMNA gene (c.1824C>T) leading to the production of a toxic form of the prelamin A protein called progerin. Because farnesylation process had been shown to control progerin toxicity, in this study we have developed a screening method permitting to identify new pharmacological inhibitors of farnesylation. For this, we have used the unique potential of pluripotent stem cells to have access to an unlimited and relevant biological resource and test 21,608 small molecules. This study identified several compounds, called monoaminopyrimidines, which target two key enzymes of the farnesylation process, farnesyl pyrophosphate synthase and farnesyl transferase, and rescue in vitro phenotypes associated with HGPS. Our results opens up new therapeutic possibilities for the treatment of HGPS by identifying a new family of protein farnesylation inhibitors, and which may also be applicable to cancers and diseases associated with mutations that involve farnesylated proteins.

  12. Reversible inactivation of the transcriptional function of P53 protein by farnesylation

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    Berg Danièle

    2006-05-01

    Full Text Available Abstract Background The use of integrating viral vectors in Gene therapy clinical trials has pointed out the problem of the deleterous effect of the integration of the ectopic gene to the cellular genome and the safety of this strategy. We proposed here a way to induce the death of gene modified cells upon request by acting on a pro-apoptotic protein cellular localization and on the activation of its apoptotic function. Results We constructed an adenoviral vector coding a chimeric p53 protein by fusing p53 sequence with the 21 COOH term amino acids sequence of H-Ras. Indeed, the translation products of Ras genes are cytosolic proteins that become secondarily associated with membranes through a series of post-translational modifications initiated by a CAAX motif present at the C terminus of Ras proteins. The chimeric p53HRCaax protein was farnesylated efficiently in transduced human osteosarcoma p53-/- cell line. The farnesylated form of p53 resided mainly in the cytosol, where it is non-functional. Farnesyl transferase inhibitors (FTIs specifically inhibited farnesyl isoprenoid lipid modification of proteins. Following treatment of the cells with an FTI, p53HRCaax underwent translocation into the nucleus where it retained transcription factor activity. Shifting p53 into the nucleus resulted in the induction of p21waf1/CIP1 and Bax transcription, cell growth arrest, caspase activation and apoptosis. Conclusion Artificial protein farnesylation impaired the transcriptional activity of p53. This could be prevented by Farnesyl transferase inhibition. These data highlight the fact that the artificial prenylation of proteins provides a novel system for controlling the function of a transactivating factor.

  13. A novel role of farnesylation in targeting a mitotic checkpoint protein, human Spindly, to kinetochores

    Science.gov (United States)

    Moudgil, Devinderjit K.; Westcott, Nathan; Famulski, Jakub K.; Patel, Kinjal; Macdonald, Dawn; Hang, Howard

    2015-01-01

    Kinetochore (KT) localization of mitotic checkpoint proteins is essential for their function during mitosis. hSpindly KT localization is dependent on the RZZ complex and hSpindly recruits the dynein–dynactin complex to KTs during mitosis, but the mechanism of hSpindly KT recruitment is unknown. Through domain-mapping studies we characterized the KT localization domain of hSpindly and discovered it undergoes farnesylation at the C-terminal cysteine residue. The N-terminal 293 residues of hSpindly are dispensable for its KT localization. Inhibition of farnesylation using a farnesyl transferase inhibitor (FTI) abrogated hSpindly KT localization without affecting RZZ complex, CENP-E, and CENP-F KT localization. We showed that hSpindly is farnesylated in vivo and farnesylation is essential for its interaction with the RZZ complex and hence KT localization. FTI treatment and hSpindly knockdown displayed the same mitotic phenotypes, indicating that hSpindly is a key FTI target in mitosis. Our data show a novel role of lipidation in targeting a checkpoint protein to KTs through protein–protein interaction. PMID:25825516

  14. Lamin A, farnesylation and aging

    Energy Technology Data Exchange (ETDEWEB)

    Reddy, Sita [Department of Biochemistry and Molecular Biology, Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033 (United States); Comai, Lucio, E-mail: comai@usc.edu [Department of Molecular Microbiology and Immunology, Institute for Genetic Medicine, Keck School of Medicine, University of Southern California, Los Angeles, CA 90033 (United States)

    2012-01-01

    Lamin A is a component of the nuclear envelope that is synthesized as a precursor prelamin A molecule and then processed into mature lamin A through sequential steps of posttranslational modifications and proteolytic cleavages. Remarkably, over 400 distinct point mutations have been so far identified throughout the LMNA gene, which result in the development of at least ten distinct human disorders, collectively known as laminopathies, among which is the premature aging disease Hutchinson-Gilford progeria syndrome (HGPS). The majority of HGPS cases are associated with a single point mutation in the LMNA gene that causes the production of a permanently farnesylated mutant lamin A protein termed progerin. The mechanism by which progerin leads to premature aging and the classical HGPS disease phenotype as well as the relationship between this disorder and the onset of analogous symptoms during the lifespan of a normal individual are not well understood. Yet, recent studies have provided critical insights on the cellular processes that are affected by accumulation of progerin and have suggested that cellular alterations in the lamin A processing pathway leading to the accumulation of farnesylated prelamin A intermediates may play a role in the aging process in the general population. In this review we provide a short background on lamin A and its maturation pathway and discuss the current knowledge of how progerin or alterations in the prelamin A processing pathway are thought to influence cell function and contribute to human aging.

  15. Glutathione transferases.

    Science.gov (United States)

    Dixon, David P; Edwards, Robert

    2010-01-01

    The 55 Arabidopsis glutathione transferases (GSTs) are, with one microsomal exception, a monophyletic group of soluble enzymes that can be divided into phi, tau, theta, zeta, lambda, dehydroascorbate reductase (DHAR) and TCHQD classes. The populous phi and tau classes are often highly stress inducible and regularly crop up in proteomic and transcriptomic studies. Despite much study on their xenobiotic-detoxifying activities their natural roles are unclear, although roles in defence-related secondary metabolism are likely. The smaller DHAR and lambda classes are likely glutathione-dependent reductases, the zeta class functions in tyrosine catabolism and the theta class has a putative role in detoxifying oxidised lipids. This review describes the evidence for the functional roles of GSTs and the potential for these enzymes to perform diverse functions that in many cases are not "glutathione transferase" activities. As well as biochemical data, expression data from proteomic and transcriptomic studies are included, along with subcellular localisation experiments and the results of functional genomic studies.

  16. Influence of class M1 glutathione S-transferase (GST Mu) polymorphism on GST M1 gene expression level and tumor size in oral squamous cell carcinoma.

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    Koch, F P; Kämmerer, P W; Kämmerer, P; Al-Nawas, B; Brieger, J

    2010-02-01

    Glutathione S-transferases (GST) are antioxidant enzymes and oxidative stress markers in oral carcinogenesis. They present a system of polymorphic proteins. Some variants are associated with increased sensitivity to toxic compounds, as it is known for the GSTM1-null variant allele. However, the influence of the GSTM1 allele variant genotype on GSTM1-mRNA quantity in oral squamous cell carcinoma (OSCC) and normal mucosa as well as the impact on prognosis remains unclear. The genotype for GSTM1 (mutation vs. wild type) was determined by polymerase chain reaction (PCR) using genomic DNA extracted from peripheral blood from 28 OSCC patients. From the same patients, 28 pairs of OSCC cells and normal oral mucosal cells were obtained by brush biopsy. mRNA was extracted from these paired samples and the expression levels of GSTM1 were examined by real-time reverse transcriptase qPCR (RT-qPCR). The mRNA expression of the OSCC samples was normalized against an external standard, as well as to the corresponding normal mucosa. The coincidence of GSTM1 genotype and GSTM1-mRNA-expression level was examined. In 15 patients (54%), the null genotype GSTM1 was present. In the GSTM1-null allele group, the GSTM1 gene expression level was determined at 1.63 (mean: 3.08; SD 3.4) folds vs. 3.6 (mean: 10.5; SD 14.2) folds in the group with the positive genotype (p=0.06), if calibrated vs. individual normal mucosa. More T3 and T4 OSCCs (+38%), higher UICC stadia (+38%) and more lymphatic metastasis (+28%) were seen in the group with the negative allele. Furthermore, positive GSTM1 genotype and enhanced GSTM1 gene expression was accompanied with increased tumor size, lymphatic metastasis status and UICC stadium. A coincidence of null type GSTM1 and lowered GSTM1 gene expression was observed. The larger tumors and more frequent lymph node metastases in this group could be explained by the insufficient cell protection by GST.

  17. Insect glutathione transferases.

    Science.gov (United States)

    Ketterman, Albert J; Saisawang, Chonticha; Wongsantichon, Jantana

    2011-05-01

    This article is an overview of the current knowledge of insect glutathione transferases. Three major topics are discussed: the glutathione transferase contributions to insecticide resistance, the polymorphic nature of the insect glutathione transferase superfamily, and a summary of the current structure-function studies on insect glutathione transferases.

  18. Characterization of human palmitoyl-acyl transferase activity using peptides that mimic distinct palmitoylation motifs.

    OpenAIRE

    Varner, Amanda S; Ducker, Charles E; Xia, Zuping; Zhuang, Yan; De Vos, Mackenzie L; Smith, Charles D.

    2003-01-01

    The covalent attachment of palmitate to proteins commonly occurs on cysteine residues near either N-myristoylated glycine residues or C-terminal farnesylated cysteine residues. It therefore seems likely that multiple palmitoyl-acyl transferase (PAT) activities exist to recognize and modify these distinct palmitoylation motifs. To evaluate this possibility, two synthetic peptides representing these palmitoylation motifs, termed MyrGCK(NBD) and FarnCNRas(NBD), were used to characterize PAT acti...

  19. Alendronate is a specific, nanomolar inhibitor of farnesyl diphosphate synthase.

    Science.gov (United States)

    Bergstrom, J D; Bostedor, R G; Masarachia, P J; Reszka, A A; Rodan, G

    2000-01-01

    Alendronate, a nitrogen-containing bisphosphonate, is a potent inhibitor of bone resorption used for the treatment and prevention of osteoporosis. Recent findings suggest that alendronate and other N-containing bisphosphonates inhibit the isoprenoid biosynthesis pathway and interfere with protein prenylation, as a result of reduced geranylgeranyl diphosphate levels. This study identified farnesyl disphosphate synthase as the mevalonate pathway enzyme inhibited by bisphosphonates. HPLC analysis of products from a liver cytosolic extract narrowed the potential targets for alendronate inhibition (IC(50) = 1700 nM) to isopentenyl diphosphate isomerase and farnesyl diphosphate synthase. Recombinant human farnesyl diphosphate synthase was inhibited by alendronate with an IC(50) of 460 nM (following 15 min preincubation). Alendronate did not inhibit isopentenyl diphosphate isomerase or GGPP synthase, partially purified from liver cytosol. Recombinant farnesyl diphosphate synthase was also inhibited by pamidronate (IC(50) = 500 nM) and risedronate (IC(50) = 3.9 nM), negligibly by etidronate (IC50 = 80 microM), and not at all by clodronate. In osteoclasts, alendronate inhibited the incorporation of [(3)H]mevalonolactone into proteins of 18-25 kDa and into nonsaponifiable lipids, including sterols. These findings (i) identify farnesyl diphosphate synthase as the selective target of alendronate in the mevalonate pathway, (ii) show that this enzyme is inhibited by other N-containing bisphosphonates, such as risendronate, but not by clodronate, supporting a different mechanism of action for different bisphosphonates, and (iii) document in purified osteoclasts alendronate inhibition of prenylation and sterol biosynthesis.

  20. Synthesis of pyrophosphonic acid analogues of farnesyl pyrophosphate

    NARCIS (Netherlands)

    Valentijn, A.R.P.M.; Berg, O. van den; Marel, G.A. van der; Cohen, L.H.; Boom, J.H. van

    1995-01-01

    The synthesis of four new analogues (i.e. 3-6) of farnesyl pyrophosphate (FPP), which may function as inhibitor of squalene synthase, is described. Compounds 3 and 4 were readily accessible by reaction of farnesal with diethyl phosphite or dimethyl lithiomethylphosphonate, respectively, followed by

  1. Synthesis of pyrophosphonic acid analogues of farnesyl pyrophosphate

    NARCIS (Netherlands)

    Valentijn, A.R.P.M.; Berg, O. van den; Marel, G.A. van der; Cohen, L.H.; Boom, J.H. van

    1995-01-01

    The synthesis of four new analogues (i.e. 3-6) of farnesyl pyrophosphate (FPP), which may function as inhibitor of squalene synthase, is described. Compounds 3 and 4 were readily accessible by reaction of farnesal with diethyl phosphite or dimethyl lithiomethylphosphonate, respectively, followed by

  2. Transferases in Polymer Chemistry

    Science.gov (United States)

    van der Vlist, Jeroen; Loos, Katja

    Transferases are enzymes that catalyze reactions in which a group is transferred from one compound to another. This makes these enzymes ideal catalysts for polymerization reactions. In nature, transferases are responsible for the synthesis of many important natural macromolecules. In synthetic polymer chemistry, various transferases are used to synthesize polymers in vitro. This chapter reviews some of these approaches, such as the enzymatic polymerization of polyesters, polysaccharides, and polyisoprene.

  3. NMR characterization of full-length farnesylated and non-farnesylated H-Ras and its implications for Raf activation.

    Science.gov (United States)

    Thapar, Roopa; Williams, Jason G; Campbell, Sharon L

    2004-11-01

    The C terminus, also known as the hypervariable region (residues 166-189), of H-, N-, and K-Ras proteins has sequence determinants necessary for full activation of downstream effectors such as Raf kinase and PI-3 kinase as well as for the correct targeting of Ras proteins to lipid rafts and non-raft membranes. There is considerable interest in understanding how residues in the extreme C terminus of the different Ras proteins and farnesylation of the CaaX box cysteine affect Ras membrane localization and allosteric activation of Raf kinase. To provide insights into the structural and dynamic changes that occur in Ras upon farnesylation, we have used NMR spectroscopy to compare the properties of truncated H-Ras (1-166), to non-processed full-length H-Ras (residues 1-185) and full-length (1-189) farnesylated H-Ras. We report that the C-terminal helix alpha-5 extends to residue N172, and the remaining 17 amino acid residues in the C terminus are conformationally averaged in solution. Removal of either 23 or 18 amino acid residues from the C terminus of full length H-Ras generates truncated H-Ras (1-166) and H-Ras (1-171) proteins, respectively, that have been structurally characterized and are biochemical active. Here we report that C-terminal truncation of H-Ras results in minor structural and dynamic perturbations that are propagated throughout the H-Ras protein including increased flexibility of the central beta-sheet and the C-terminal helix alpha-5. Ordering of residues in loop-2, which is involved in Raf CRD binding is also observed. Farnesylation of full-length H-Ras at C186 does not result in detectable conformational changes in H-Ras. Chemical shift mapping studies of farnesylated and non-farnesylated forms of H-Ras with the Raf-CRD show that the farnesyl moiety, the extreme H-Ras C terminus and residues 23-30, contribute to H-Ras:Raf-CRD interactions, thereby increasing the affinity of H-Ras for the Raf-CRD.

  4. Cloning and enzymology analysis of farnesyl pyrophosphate synthase gene from a superior strain of Artemisia annua L

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A cDNA(af1) encoding farnesyl pyrophosphate synthase AaFPS1 (FPS, EC2.5.1.1/EC2.5.1.10) from a high yield Artemisia annua strain 025 has been cloned from its cDNA library. Sequence analysis showed that the cDNA encoded a protein of 343 amino acid (aa) residues with molecular weight of 39 kD. Deduced aa sequence of the cDNA was similar to FPS from other plants, yeast and mammals, containing 5 conserved domains found in both prenyl transferase and polyprenyl synthase. The expression of the cDNA in Escherichia coli showed measurable specific activity of FPS in vitro. The enzyme was purified by ion exchange chromatography and its kinetics was measured. These results would further promote the molecular regulation of artemisinin biosynthesis.

  5. Transferases in Polymer Chemistry

    NARCIS (Netherlands)

    van der Vlist, Jeroen; Loos, Katja; Palmans, ARA; Heise, A

    2010-01-01

    Transferases are enzymes that catalyze reactions in which a group is transferred from one compound to another. This makes these enzymes ideal catalysts for polymerization reactions. In nature, transferases are responsible for the synthesis of many important natural macromolecules. In synthetic polym

  6. Propiconazole-enhanced hepatic cell proliferation is associated with dysregulation of the cholesterol biosynthesis pathway leading to activation of Erk1/2 through Ras farnesylation

    Energy Technology Data Exchange (ETDEWEB)

    Murphy, Lynea A.; Moore, Tanya; Nesnow, Stephen, E-mail: nesnow.stephen@epa.gov

    2012-04-15

    Propiconazole is a mouse hepatotumorigenic fungicide designed to inhibit CYP51, a key enzyme in the biosynthesis of ergosterol in fungi and is widely used in agriculture to prevent fungal growth. Metabolomic studies in mice revealed that propiconazole increased levels of hepatic cholesterol metabolites and bile acids, and transcriptomic studies revealed that genes within the cholesterol biosynthesis, cholesterol metabolism and bile acid biosyntheses pathways were up-regulated. Hepatic cell proliferation was also increased by propiconazole. AML12 immortalized hepatocytes were used to study propiconazole's effects on cell proliferation focusing on the dysregulation of cholesterol biosynthesis and resulting effects on Ras farnesylation and Erk1/2 activation as a primary pathway. Mevalonate, a key intermediate in the cholesterol biosynthesis pathway, increases cell proliferation in several cancer cell lines and tumors in vivo and serves as the precursor for isoprenoids (e.g. farnesyl pyrophosphate) which are crucial in the farnesylation of the Ras protein by farnesyl transferase. Farnesylation targets Ras to the cell membrane where it is involved in signal transduction, including the mitogen-activated protein kinase (MAPK) pathway. In our studies, mevalonic acid lactone (MVAL), a source of mevalonic acid, increased cell proliferation in AML12 cells which was reduced by farnesyl transferase inhibitors (L-744,832 or manumycin) or simvastatin, an HMG-CoA reductase inhibitor, indicating that this cell system responded to alterations in the cholesterol biosynthesis pathway. Cell proliferation in AML12 cells was increased by propiconazole which was reversed by co-incubation with L-744,832 or simvastatin. Increasing concentrations of exogenous cholesterol muted the proliferative effects of propiconazole and the inhibitory effects of L-733,832, results ascribed to reduced stimulation of the endogenous cholesterol biosynthesis pathway. Western blot analysis of subcellular

  7. Autophagic degradation of farnesylated prelamin A as a therapeutic approach to lamin-linked progeria

    OpenAIRE

    V. Cenni; C. Capanni; Columbaro, M.; Ortolani, M.; M.R. D'Apice; Novelli, G; Fini, M.; S. Marmiroli; Scarano, E.; Maraldi, N.M.; Squarzoni, S.; S. Prencipe; Lattanzi, G

    2011-01-01

    Farnesylated prelamin A is a processing intermediate produced in the lamin A maturation pathway. Accumulation of a truncated farnesylated prelamin A form, called progerin, is a hallmark of the severe premature ageing syndrome, Hutchinson-Gilford progeria. Progerin elicits toxic effects in cells, leading to chromatin damage and cellular senescence and ultimately causes skin and endothelial defects, bone resorption, lipodystrophy and accelerated ageing. Knowledge of the mechanism underlying pre...

  8. Glutathione transferases in bacteria.

    Science.gov (United States)

    Allocati, Nerino; Federici, Luca; Masulli, Michele; Di Ilio, Carmine

    2009-01-01

    Bacterial glutathione transferases (GSTs) are part of a superfamily of enzymes that play a key role in cellular detoxification. GSTs are widely distributed in prokaryotes and are grouped into several classes. Bacterial GSTs are implicated in a variety of distinct processes such as the biodegradation of xenobiotics, protection against chemical and oxidative stresses and antimicrobial drug resistance. In addition to their role in detoxification, bacterial GSTs are also involved in a variety of distinct metabolic processes such as the biotransformation of dichloromethane, the degradation of lignin and atrazine, and the reductive dechlorination of pentachlorophenol. This review article summarizes the current status of knowledge regarding the functional and structural properties of bacterial GSTs.

  9. Andrastin A and barceloneic acid metabolites, protein farnesyl transferase inhibitors from Penicillium alborcoremium: chemotaxonomic significance and pathological implications

    DEFF Research Database (Denmark)

    Overy, David Patrick; Larsen, Thomas Ostenfeld; Dalsgaard, P.W.;

    2005-01-01

    of a barceloneic acid being produced as a secondary metabolite. Tissue extracts created following pathogenicity trials involving P. albocoremium and Allium cepa confirmed the production of these five metabolites in planta. Barceloneic acid B was found to be biologically active against a P388 murine leukemia cell...

  10. Andrastin A and barceloneic acid metabolites, protein farnesyl transferase inhibitors from Penicillium alborcoremium: chemotaxonomic significance and pathological implications

    DEFF Research Database (Denmark)

    Overy, David Patrick; Larsen, Thomas Ostenfeld; Dalsgaard, P.W.

    2005-01-01

    A survey of Penicillium albocoremium was undertaken to identify potential taxonomic metabolite markers. One major and four minor metabolites were consistently produced by the 19 strains surveyed on three different media. Following purification and spectral studies, the metabolites were identified...

  11. Mammalian cytosolic glutathione transferases.

    Science.gov (United States)

    Dourado, Daniel F A R; Fernandes, Pedro Alexandrino; Ramos, Maria João

    2008-08-01

    Glutathione Transferases (GSTs) are crucial enzymes in the cell detoxification process catalyzing the nucleophilic attack of glutathione (GSH) on toxic electrophilic substrates and producing a less dangerous compound. GSTs studies are of great importance since they have been implicated in the development of drug resistance in tumoral cells and are related to human diseases such as Parkinson's, Alzheimer's, atherosclerois, liver cirrhosis, aging and cataract formation. In this review we start by providing an evolutionary perspective of the mammalian cytosolic GSTs known to date. Later on we focus on the more abundant classes alpha, mu and pi and their structure, catalysis, metabolic associated functions, drug resistance relation and inhibition methods. Finally, we introduce the recent insights on the GST class zeta from a metabolic perspective.

  12. Generation of self-clusters of galectin-1 in the farnesyl-bound form

    Science.gov (United States)

    Yamaguchi, Kazumi; Niwa, Yusuke; Nakabayashi, Takakazu; Hiramatsu, Hirotsugu

    2016-09-01

    Ras protein is involved in a signal transduction cascade in cell growth, and cluster formation of H-Ras and human galectin-1 (Gal-1) complex is considered to be crucial to achieve its physiological roles. It is considered that the complex is formed through interactions between Gal-1 and the farnesyl group (farnesyl-dependent model), post-translationally modified to the C-terminal Cys, of H-Ras. We investigated the role of farnesyl-bound Gal-1 in the cluster formation by analyzing the structure and properties of Gal-1 bound to farnesyl thiosalicylic acid (FTS), a competitive inhibitor of the binding of H-Ras to Gal-1. Gal-1 exhibited self-cluster formation upon interaction with FTS, and small- and large-size clusters were formed depending on FTS concentration. The galactoside-binding pocket of Gal-1 in the FTS-bound form was found to play an important role in small-size cluster formation. Large-size clusters were likely formed by the interaction among the hydrophobic sites of Gal-1 in the FTS-bound form. The present results indicate that Gal-1 in the FTS-bound form has the ability to form self-clusters as well as intrinsic lectin activity. Relevance of the self-clustering of FTS-bound Gal-1 to the cluster formation of the H-Ras-Gal-1complex was discussed by taking account of the farnesyl-dependent model and another (Raf-dependent) model.

  13. Molecular Cloning of Adenosinediphosphoribosyl Transferase.

    Science.gov (United States)

    1987-09-08

    ACCESSION NO.D,. 03261102F 2312 A~5 11. TITLE (include Securqt Classification) 0 Molecular Cloning of Adenosinediphosphoribosyl Transferase 12. PERSONAL...I’:- AFOSR.Tlt. 8 7 - 0 9 8,2 0IL * pi AFOSR- 85 -0377 PROGRESS REPORT Molecular Cloning of Adenosinediphosphoribosyl Transferase 5." Period of...Pharmacology and the Cardiovascular Research Institute September 8, 1987 .’, 5.’- "’S ". -f, AFOSR - 85 -0377 PROGRESS REPORT Molecular Cloning of

  14. An enzyme-coupled continuous fluorescence assay for farnesyl diphosphate synthases.

    Science.gov (United States)

    Dozier, Jonathan K; Distefano, Mark D

    2012-02-01

    Farnesyl diphosphate synthase (FDPS) catalyzes the conversion of isopentenyl diphosphate and dimethylallyl diphosphate to farnesyl diphosphate, a crucial metabolic intermediate in the synthesis of cholesterol, ubiquinone, and prenylated proteins; consequently, much effort has gone into developing inhibitors that target FDPS. Currently most FDPS assays either use radiolabeled substrates and are discontinuous or monitor pyrophosphate release and not farnesyl diphosphate (FPP) creation. Here we report the development of a continuous coupled enzyme assay for FDPS activity that involves the subsequent incorporation of the FPP product of that reaction into a peptide via the action of protein farnesyltransferase (PFTase). By using a dansylated peptide whose fluorescence quantum yield increases upon farnesylation, the rate of FDPS-catalyzed FPP production can be measured. We show that this assay is more sensitive than existing coupled assays, that it can be used to conveniently monitor FDPS activity in a 96-well plate format, and that it can reproduce IC(50) values for several previously reported FDPS inhibitors. This new method offers a simple, safe, and continuous method to assay FDPS activity that should greatly facilitate the screening of inhibitors of this important target.

  15. Autophagic degradation of farnesylated prelamin A as a therapeutic approach to lamin-linked progeria

    Science.gov (United States)

    Cenni, V.; Capanni, C.; Columbaro, M.; Ortolani, M.; D'Apice, M.R.; Novelli, G.; Fini, M.; Marmiroli, S.; Scarano, E.; Maraldi, N.M.; Squarzoni, S.; Prencipe, S.; Lattanzi, G.

    2011-01-01

    Farnesylated prelamin A is a processing intermediate produced in the lamin A maturation pathway. Accumulation of a truncated farnesylated prelamin A form, called progerin, is a hallmark of the severe premature ageing syndrome, Hutchinson-Gilford progeria. Progerin elicits toxic effects in cells, leading to chromatin damage and cellular senescence and ultimately causes skin and endothelial defects, bone resorption, lipodystrophy and accelerated ageing. Knowledge of the mechanism underlying prelamin A turnover is critical for the development of clinically effective protein inhibitors that can avoid accumulation to toxic levels without impairing lamin A/C expression, which is essential for normal biological functions. Little is known about specific molecules that may target farnesylated prelamin A to elicit protein degradation. Here, we report the discovery of rapamycin as a novel inhibitor of progerin, which dramatically and selectively decreases protein levels through a mechanism involving autophagic degradation. Rapamycin treatment of progeria cells lowers progerin, as well as wild-type prelamin A levels, and rescues the chromatin phenotype of cultured fibroblasts, including histone methylation status and BAF and LAP2α distribution patterns. Importantly, rapamycin treatment does not affect lamin C protein levels, but increases the relative expression of the prelamin A endoprotease ZMPSTE24. Thus, rapamycin, an antibiotic belonging to the class of macrolides, previously found to increase longevity in mouse models, can serve as a therapeutic tool, to eliminate progerin, avoid farnesylated prelamin A accumulation, and restore chromatin dynamics in progeroid laminopathies. PMID:22297442

  16. Autophagic degradation of farnesylated prelamin A as a therapeutic approach to lamin-linked progeria.

    Science.gov (United States)

    Cenni, V; Capanni, C; Columbaro, M; Ortolani, M; D'Apice, M R; Novelli, G; Fini, M; Marmiroli, S; Scarano, E; Maraldi, N M; Squarzoni, S; Prencipe, S; Lattanzi, G

    2011-10-19

    Farnesylated prelamin A is a processing intermediate produced in the lamin A maturation pathway. Accumulation of a truncated farnesylated prelamin A form, called progerin, is a hallmark of the severe premature ageing syndrome, Hutchinson-Gilford progeria. Progerin elicits toxic effects in cells, leading to chromatin damage and cellular senescence and ultimately causes skin and endothelial defects, bone resorption, lipodystrophy and accelerated ageing. Knowledge of the mechanism underlying prelamin A turnover is critical for the development of clinically effective protein inhibitors that can avoid accumulation to toxic levels without impairing lamin A/C expression, which is essential for normal biological functions. Little is known about specific molecules that may target farnesylated prelamin A to elicit protein degradation. Here, we report the discovery of rapamycin as a novel inhibitor of progerin, which dramatically and selectively decreases protein levels through a mechanism involving autophagic degradation. Rapamycin treatment of progeria cells lowers progerin, as well as wild-type prelamin A levels, and rescues the chromatin phenotype of cultured fibroblasts, including histone methylation status and BAF and LAP2alpha distribution patterns. Importantly, rapamycin treatment does not affect lamin C protein levels, but increases the relative expression of the prelamin A endoprotease ZMPSTE24. Thus, rapamycin, an antibiotic belonging to the class of macrolides, previously found to increase longevity in mouse models, can serve as a therapeutic tool, to eliminate progerin, avoid farnesylated prelamin A accumulation, and restore chromatin dynamics in progeroid laminopathies.

  17. Autophagic degradation of farnesylated prelamin A as a therapeutic approach to lamin-linked progeria

    Directory of Open Access Journals (Sweden)

    V. Cenni

    2011-10-01

    Full Text Available Farnesylated prelamin A is a processing intermediate produced in the lamin A maturation pathway. Accumulation of a truncated farnesylated prelamin A form, called progerin, is a hallmark of the severe premature ageing syndrome, Hutchinson-Gilford progeria. Progerin elicits toxic effects in cells, leading to chromatin damage and cellular senescence and ultimately causes skin and endothelial defects, bone resorption, lipodystrophy and accelerated ageing. Knowledge of the mechanism underlying prelamin A turnover is critical for the development of clinically effective protein inhibitors that can avoid accumulation to toxic levels without impairing lamin A/C expression, which is essential for normal biological functions. Little is known about specific molecules that may target farnesylated prelamin A to elicit protein degradation. Here, we report the discovery of rapamycin as a novel inhibitor of progerin, which dramatically and selectively decreases protein levels through a mechanism involving autophagic degradation. Rapamycin treatment of progeria cells lowers progerin, as well as wild-type prelamin A levels, and rescues the chromatin phenotype of cultured fibroblasts, including histone methylation status and BAF and LAP2alpha distribution patterns. Importantly, rapamycin treatment does not affect lamin C protein levels, but increases the relative expression of the prelamin A endoprotease ZMPSTE24. Thus, rapamycin, an antibiotic belonging to the class of macrolides, previously found to increase longevity in mouse models, can serve as a therapeutic tool, to eliminate progerin, avoid farnesylated prelamin A accumulation, and restore chromatin dynamics in progeroid laminopathies.

  18. Structure and Mechanism of the Farnesyl Diphosphate Synthase from Trypanosoma cruzi: Implications for Drug Design

    Energy Technology Data Exchange (ETDEWEB)

    Gabelli,S.; McLellan, J.; Montalvetti, A.; Oldfield, E.; Docampo, R.; Amzel, L.

    2006-01-01

    Typanosoma cruzi, the causative agent of Chagas disease, has recently been shown to be sensitive to the action of the bisphosphonates currently used in bone resorption therapy. These compounds target the mevalonate pathway by inhibiting farnesyl diphosphate synthase (farnesyl pyrophosphate synthase, FPPS), the enzyme that condenses the diphosphates of C{sub 5} alcohols (isopentenyl and dimethylallyl) to form C{sub 10} and C{sub 15} diphosphates (geranyl and farnesyl). The structures of the T. cruzi FPPS (TcFPPS) alone and in two complexes with substrates and inhibitors reveal that following binding of the two substrates and three Mg2+ ions, the enzyme undergoes a conformational change consisting of a hinge-like closure of the binding site. In this conformation, it would be possible for the enzyme to bind a bisphosphonate inhibitor that spans the sites usually occupied by dimethylallyl diphosphate (DMAPP) and the homoallyl moiety of isopentenyl diphosphate. This observation may lead to the design of new, more potent anti-trypanosomal bisphosphonates, because existing FPPS inhibitors occupy only the DMAPP site. In addition, the structures provide an important mechanistic insight: after its formation, geranyl diphosphate can swing without leaving the enzyme, from the product site to the substrate site to participate in the synthesis of farnesyl diphosphate.

  19. Coordinated cell motility is regulated by a combination of LKB1 farnesylation and kinase activity

    Science.gov (United States)

    Wilkinson, S.; Hou, Y.; Zoine, J. T.; Saltz, J.; Zhang, C.; Chen, Z.; Cooper, L. A. D.; Marcus, A. I.

    2017-01-01

    Cell motility requires the precise coordination of cell polarization, lamellipodia formation, adhesion, and force generation. LKB1 is a multi-functional serine/threonine kinase that associates with actin at the cellular leading edge of motile cells and suppresses FAK. We sought to understand how LKB1 coordinates these multiple events by systematically dissecting LKB1 protein domain function in combination with live cell imaging and computational approaches. We show that LKB1-actin colocalization is dependent upon LKB1 farnesylation leading to RhoA-ROCK-mediated stress fiber formation, but membrane dynamics is reliant on LKB1 kinase activity. We propose that LKB1 kinase activity controls membrane dynamics through FAK since loss of LKB1 kinase activity results in morphologically defective nascent adhesion sites. In contrast, defective farnesylation mislocalizes nascent adhesion sites, suggesting that LKB1 farnesylation serves as a targeting mechanism for properly localizing adhesion sites during cell motility. Together, we propose a model where coordination of LKB1 farnesylation and kinase activity serve as a multi-step mechanism to coordinate cell motility during migration. PMID:28102310

  20. Inhibition of Protein Farnesylation Arrests Adipogenesis and Affects PPARγ Expression and Activation in Differentiating Mesenchymal Stem Cells

    Science.gov (United States)

    Rivas, Daniel; Akter, Rahima; Duque, Gustavo

    2007-01-01

    Protein farnesylation is required for the activation of multiple proteins involved in cell differentiation and function. In white adipose tissue protein, farnesylation has shown to be essential for the successful differentiation of preadipocytes into adipocytes. We hypothesize that protein farnesylation is required for PPARγ2 expression and activation, and therefore for the differentiation of human mesenchymal stem cells (MSCs) into adipocytes. MSCs were plated and induced to differentiate into adipocytes for three weeks. Differentiating cells were treated with either an inhibitor of farnesylation (FTI-277) or vehicle alone. The effect of inhibition of farnesylation in differentiating adipocytes was determined by oil red O staining. Cell survival was quantified using MTS Formazan. Additionally, nuclear extracts were obtained and prelamin A, chaperon protein HDJ-2, PPARγ, and SREBP-1 were determined by western blot. Finally, DNA binding PPARγ activity was determined using an ELISA-based PPARγ activation quantification method. Treatment with an inhibitor of farnesylation (FTI-277) arrests adipogenesis without affecting cell survival. This effect was concomitant with lower levels of PPARγ expression and activity. Finally, accumulation of prelamin A induced an increased proportion of mature SREBP-1 which is known to affect PPARγ activity. In summary, inhibition of protein farnesylation arrests the adipogenic differentiation of MSCs and affects PPARγ expression and activity. PMID:18274630

  1. Inhibition of Protein Farnesylation Arrests Adipogenesis and Affects PPARgamma Expression and Activation in Differentiating Mesenchymal Stem Cells.

    Science.gov (United States)

    Rivas, Daniel; Akter, Rahima; Duque, Gustavo

    2007-01-01

    Protein farnesylation is required for the activation of multiple proteins involved in cell differentiation and function. In white adipose tissue protein, farnesylation has shown to be essential for the successful differentiation of preadipocytes into adipocytes. We hypothesize that protein farnesylation is required for PPARgamma2 expression and activation, and therefore for the differentiation of human mesenchymal stem cells (MSCs) into adipocytes. MSCs were plated and induced to differentiate into adipocytes for three weeks. Differentiating cells were treated with either an inhibitor of farnesylation (FTI-277) or vehicle alone. The effect of inhibition of farnesylation in differentiating adipocytes was determined by oil red O staining. Cell survival was quantified using MTS Formazan. Additionally, nuclear extracts were obtained and prelamin A, chaperon protein HDJ-2, PPARgamma, and SREBP-1 were determined by western blot. Finally, DNA binding PPARgamma activity was determined using an ELISA-based PPARgamma activation quantification method. Treatment with an inhibitor of farnesylation (FTI-277) arrests adipogenesis without affecting cell survival. This effect was concomitant with lower levels of PPARgamma expression and activity. Finally, accumulation of prelamin A induced an increased proportion of mature SREBP-1 which is known to affect PPARgamma activity. In summary, inhibition of protein farnesylation arrests the adipogenic differentiation of MSCs and affects PPARgamma expression and activity.

  2. Glutathione transferases and neurodegenerative diseases.

    Science.gov (United States)

    Mazzetti, Anna Paola; Fiorile, Maria Carmela; Primavera, Alessandra; Lo Bello, Mario

    2015-03-01

    There is substantial agreement that the unbalance between oxidant and antioxidant species may affect the onset and/or the course of a number of common diseases including Parkinson's and Alzheimer's diseases. Many studies suggest a crucial role for oxidative stress in the first phase of aging, or in the pathogenesis of various diseases including neurological ones. Particularly, the role exerted by glutathione and glutathione-related enzymes (Glutathione Transferases) in the nervous system appears more relevant, this latter tissue being much more vulnerable to toxins and oxidative stress than other tissues such as liver, kidney or muscle. The present review addresses the question by focusing on the results obtained by specimens from patients or by in vitro studies using cells or animal models related to Parkinson's and Alzheimer's diseases. In general, there is an association between glutathione depletion and Parkinson's or Alzheimer's disease. In addition, a significant decrease of glutathione transferase activity in selected areas of brain and in ventricular cerebrospinal fluid was found. For some glutathione transferase genes there is also a correlation between polymorphisms and onset/outcome of neurodegenerative diseases. Thus, there is a general agreement about the protective effect exerted by glutathione and glutathione transferases but no clear answer about the mechanisms underlying this crucial role in the insurgence of neurodegenerative diseases.

  3. Identification of a quorum sensing pheromone posttranslationally farnesylated at the internal tryptophan residue from Bacillus subtilis subsp. natto.

    Science.gov (United States)

    Hayashi, Shunsuke; Usami, Syohei; Nakamura, Yuta; Ozaki, Koki; Okada, Masahiro

    2015-01-01

    Bacillus subtilis subsp. natto produces poly-γ-glutamic acid under the control of quorum sensing. We identified ComXnatto pheromone as the quorum-sensing pheromone with an amino acid sequence of Lys-Trp-Pro-Pro-Ile-Glu and the tryptophan residue posttranslationally modified by a farnesyl group. ComXnatto pheromone is unique in the sense that the 5th tryptophan residue from the C-terminal is farnesylated.

  4. Synthesis of high specific activity (1- sup 3 H) farnesyl pyrophosphate

    Energy Technology Data Exchange (ETDEWEB)

    Saljoughian, M.; Morimoto, H.; Williams, P.G.

    1991-08-01

    The synthesis of tritiated farnesyl pyrophosphate with high specific activity is reported. trans-trans Farnesol was oxidized to the corresponding aldehyde followed by reduction with lithium aluminium tritide (5%-{sup 3}H) to give trans-trans (1-{sup 3}H)farnesol. The specific radioactivity of the alcohol was determined from its triphenylsilane derivative, prepared under very mild conditions. The tritiated alcohol was phosphorylated by initial conversion to an allylic halide, and subsequent treatment of the halide with tris-tetra-n-butylammonium hydrogen pyrophosphate. The hydride procedure followed in this work has advantages over existing methods for the synthesis of tritiated farnesyl pyrophosphate, with the possibility of higher specific activity and a much higher yield obtained. 10 refs., 3 figs.

  5. A Versatile Photoactivatable Probe Designed to Label the Diphosphate Binding Site of Farnesyl Diphosphate Utilizing Enzymes

    Science.gov (United States)

    Henry, Olivier; Lopez-Gallego, Fernando; Agger, Sean A.; Schmidt-Dannert, Claudia; Sen, Stephanie; Shintani, David; Cornish, Katrina; Distefano, Mark D.

    2009-01-01

    Farnesyl diphosphate (FPP) is a substrate for a diverse number of enzymes found in nature. Photoactive analogues of isoprenoid diphosphates containing either benzophenone, diazotrifluropropionate or azide groups have been useful for studying both the enzymes that synthesize FPP as well as those that employ FPP as a substrate. Here we describe the synthesis and properties of a new class of FPP analogues that links an unmodified farnesyl group to a diphosphate mimic containing a photoactive benzophenone moiety; thus, importantly, these compounds are photoactive FPP analogues that contain no modifications of the isoprenoid portion of the molecule that may interfere with substrate binding in the active site of an FPP utilizing enzyme. Two isomeric compounds containing meta- and para-substituted benzophenones were prepared. These two analogues inhibit S. cerevisiae protein farnesyltransferase (ScPFTase) with IC50 values of 5.8 (meta isomer) and 3.0 µM (para isomer); the more potent analogue, the para isomer, was shown to be a competitive inhibitor of ScPFTase with respect to FPP with a KI of 0.46 µM. Radiolabeled forms of both analogues selectively labelled the β-subunit of ScPFTase. The para isomer was also shown to label E. coli farnesyl diphosphate synthase and Drosophila melanogaster farnesyl diphosphate synthase. Finally, the para isomer was shown to be an alternative substrate for a sesquiterpene synthase from Nostoc sp. strain PCC7120, a cyanobacterial source; the compound also labeled the purified enzyme upon photolysis. Taken together, these results using a number of enzymes demonstrate that this new class of probes should be useful for a plethora of studies of FPP-utilizing enzymes. PMID:19447628

  6. Synthesis and antibacterial evaluation of 3-Farnesyl-2-hydroxybenzoic acid from Piper multiplinervium.

    Science.gov (United States)

    Malami, Ibrahim; Gibbons, Simon; Malkinson, John P

    2014-03-01

    3-Farnesyl-2-hydroxybenzoic acid is an antibacterial agent isolated from the leaves of Piper multiplinervium. This compound has activity against both Gram positive and Gram negative bacteria including Escherichia coli, Staphylococcus aureus and Helicobacter pylori. This research aimed to synthesize a natural antibacterial compound and its analogs. The synthesis of 3-Farnesyl-2-hydroxybenzoic acid consists of three steps: straightforward synthesis involving protection of phenolic hydroxyl group, coupling of suitable isoprenyl chain to the protected aromatic ring at ortho position followed by carboxylation with concomitant deprotection to give the derivatives of the salicylic acid. All the three prenylated compounds synthesized were found to exhibit spectrum of activity against S. aureus (ATCC) having MIC: 5.84×10(-3), 41.46×10(-2) and 6.19×10(-1) μmol/ml respectively. The compounds also displayed activity against resistance strain of S. aureus (SA1119B) having MIC: 5.84×10(-3), 7.29×10(-3) and 3.09×10(-1) μmol/ml respectively. This synthesis has been achieved and accomplished with the confirmation of it structure to that of the original natural product, thus producing the first synthesis of the natural product and providing the first synthesis of its analogs with 3-Farnesyl-2-hydroxybenzoic acid having biological activity higher than that of the original natural product.

  7. A New Farnesyl Diphosphate Synthase Gene from Taxus media Rehder: Cloning, Characterization and Functional Complementation

    Institute of Scientific and Technical Information of China (English)

    Zhi-Hua Liao; Min Chen; Yi-Fu Gong; Zhu-Gang Li; Kai-Jing Zuo; Peng Wang; Feng Tan; Xiao-Fen Sun; Ke-Xuan Tang

    2006-01-01

    Farnesyl diphosphate synthase (FPS; EC 2.5.1.10) catalyzes the production of 15-carbon farnesyl diphosphate which is a branch-point intermediate for many terpenoids. This reaction is considered to be a ratelimiting step in terpenoid biosynthesis. Here we report for the first time the cloning of a new full-length cDNA encoding farnesyl diphosphate synthase from a gymnosperm plant species, Taxus media Rehder,designated as TmFPS1. The full-length cDNA of TmFPS1 (GenBank accession number: AY461811) was 1 464bp with a 1 056-bp open reading frame encoding a 351-amino acid polypeptide with a calculated molecular weight of 40.3 kDa and a theoretical pl of 5.07. Bioinformatic analysis revealed that TmFPS1 contained all five conserved domains of prenyltransferases, and showed homology to other FPSs of plant origin. Phylogenetic analysis showed that farnesyl diphosphate synthases can be divided into two groups: one of prokaryotic origin and the other of eukaryotic origin. TmFPS1 was grouped with FPSs of plant origin. Homologybased structural modeling showed that TmFPS1 had the typical spatial structure of FPS, whose most prominent structural feature is the arrangement of 13 core helices around a large central cavity in which the catalytic reaction takes place. Our bioinformatic analysis strongly suggests that TmFPS1 is a functional gene. Southern blot analysis revealed that TmFPS1 belongs to a small FPS gene family in T. media. Northern blot analysis indicated that TmFPS1 is expressed in all tested tissues, including the needles, stems and roots of T. media. Subsequently, functional complementation with TmFPS1 in a FPS-deficient mutant yeast demonstrated that TmFPS1 did encode farnesyl diphosphate synthase, which rescued the yeast mutant.This study will be helpful in future investigations aiming at understanding the detailed role of FPS in terpenoid biosynthesis flux control at the molecular genetic level.

  8. Permanent farnesylation of lamin A mutants linked to progeria impairs its phosphorylation at serine 22 during interphase.

    Science.gov (United States)

    Moiseeva, Olga; Lopes-Paciencia, Stéphane; Huot, Geneviève; Lessard, Frédéric; Ferbeyre, Gerardo

    2016-02-01

    Mutants of lamin A cause diseases including the Hutchinson-Gilford progeria syndrome (HGPS) characterized by premature aging. Lamin A undergoes a series of processing reactions, including farnesylation and proteolytic cleavage of the farnesylated C-terminal domain. The role of cleavage is unknown but mutations that affect this reaction lead to progeria. Here we show that interphase serine 22 phosphorylation of endogenous mutant lamin A (progerin) is defective in cells from HGPS patients. This defect can be mimicked by expressing progerin in human cells and prevented by inhibition of farnesylation. Furthermore, serine 22 phosphorylation of non-farnesylated progerin was enhanced by a mutation that disrupts lamin A head to tail interactions. The phosphorylation of lamin A or non-farnesylated progerin was associated to the formation of spherical intranuclear lamin A droplets that accumulate protein kinases of the CDK family capable of phosphorylating lamin A at serine 22. CDK inhibitors compromised the turnover of progerin, accelerated senescence of HGPS cells and reversed the effects of FTI on progerin levels. We discuss a model of progeria where faulty serine 22 phosphorylation compromises phase separation of lamin A polymers, leading to accumulation of functionally impaired lamin A structures.

  9. Hibiscus cannabinus feruloyl-coa:monolignol transferase

    Energy Technology Data Exchange (ETDEWEB)

    Wilkerson, Curtis; Ralph, John; Withers, Saunia; Mansfield, Shawn D.

    2016-11-15

    The invention relates to isolated nucleic acids encoding a feruloyl-CoA:monolignol transferase and feruloyl-CoA:monolignol transferase enzymes. The isolated nucleic acids and/or the enzymes enable incorporation of monolignol ferulates into the lignin of plants, where such monolignol ferulates include, for example, p-coumaryl ferulate, coniferyl ferulate, and/or sinapyl ferulate. The invention also includes methods and plants that include nucleic acids encoding a feruloyl-CoA:monolignol transferase enzyme and/or feruloyl-CoA:monolignol transferase enzymes.

  10. Cyclization of farnesyl pyrophosphate to the sesquiterpene olefins humulene and caryophyllene by an enzyme system from sage (Salvia officinalis)

    Energy Technology Data Exchange (ETDEWEB)

    Croteau, R.; Gundy, A.

    1984-09-01

    A soluble enzyme preparation obtained from sage (Salvia officinalis) leaves was shown to catalyze the divalent metal-ion dependent cyclization of trans, trans-farnesyl pyrophosphate to the macrocyclic sesquiterpene olefins humulene and caryophyllene. The identities of the biosynthetic products were confirmed by radiochromatographic analysis and by preparation of crystalline derivatives, and the specificity of labeling in the cyclization reaction was established by chemical degradation of the olefins derived enzymatically from (1-3H2)farnesyl pyrophosphate. These results constitute the first report on the cyclization of farnesyl pyrophosphate to humulene and caryophyllene, two of the most common sesquiterpenes in nature, and the first description of a soluble sesquiterpene cyclase to be isolated from leaves of a higher plant.

  11. Role of protein farnesylation in burn-induced metabolic derangements and insulin resistance in mouse skeletal muscle.

    Directory of Open Access Journals (Sweden)

    Harumasa Nakazawa

    Full Text Available OBJECTIVE: Metabolic derangements, including insulin resistance and hyperlactatemia, are a major complication of major trauma (e.g., burn injury and affect the prognosis of burn patients. Protein farnesylation, a posttranslational lipid modification of cysteine residues, has been emerging as a potential component of inflammatory response in sepsis. However, farnesylation has not yet been studied in major trauma. To study a role of farnesylation in burn-induced metabolic aberration, we examined the effects of farnesyltransferase (FTase inhibitor, FTI-277, on burn-induced insulin resistance and metabolic alterations in mouse skeletal muscle. METHODS: A full thickness burn (30% total body surface area was produced under anesthesia in male C57BL/6 mice at 8 weeks of age. After the mice were treated with FTI-277 (5 mg/kg/day, IP or vehicle for 3 days, muscle insulin signaling, metabolic alterations and inflammatory gene expression were evaluated. RESULTS: Burn increased FTase expression and farnesylated proteins in mouse muscle compared with sham-burn at 3 days after burn. Simultaneously, insulin-stimulated phosphorylation of insulin receptor (IR, insulin receptor substrate (IRS-1, Akt and GSK-3β was decreased. Protein expression of PTP-1B (a negative regulator of IR-IRS-1 signaling, PTEN (a negative regulator of Akt-mediated signaling, protein degradation and lactate release by muscle, and plasma lactate levels were increased by burn. Burn-induced impaired insulin signaling and metabolic dysfunction were associated with increased inflammatory gene expression. These burn-induced alterations were reversed or ameliorated by FTI-277. CONCLUSIONS: Our data demonstrate that burn increased FTase expression and protein farnesylation along with insulin resistance, metabolic alterations and inflammatory response in mouse skeletal muscle, all of which were prevented by FTI-277 treatment. These results indicate that increased protein farnesylation plays a

  12. Farnesylated and methylated KRAS4b: high yield production of protein suitable for biophysical studies of prenylated protein-lipid interactions.

    Science.gov (United States)

    Gillette, William K; Esposito, Dominic; Abreu Blanco, Maria; Alexander, Patrick; Bindu, Lakshman; Bittner, Cammi; Chertov, Oleg; Frank, Peter H; Grose, Carissa; Jones, Jane E; Meng, Zhaojing; Perkins, Shelley; Van, Que; Ghirlando, Rodolfo; Fivash, Matthew; Nissley, Dwight V; McCormick, Frank; Holderfield, Matthew; Stephen, Andrew G

    2015-11-02

    Prenylated proteins play key roles in several human diseases including cancer, atherosclerosis and Alzheimer's disease. KRAS4b, which is frequently mutated in pancreatic, colon and lung cancers, is processed by farnesylation, proteolytic cleavage and carboxymethylation at the C-terminus. Plasma membrane localization of KRAS4b requires this processing as does KRAS4b-dependent RAF kinase activation. Previous attempts to produce modified KRAS have relied on protein engineering approaches or in vitro farnesylation of bacterially expressed KRAS protein. The proteins produced by these methods do not accurately replicate the mature KRAS protein found in mammalian cells and the protein yield is typically low. We describe a protocol that yields 5-10 mg/L highly purified, farnesylated, and methylated KRAS4b from insect cells. Farnesylated and methylated KRAS4b is fully active in hydrolyzing GTP, binds RAF-RBD on lipid Nanodiscs and interacts with the known farnesyl-binding protein PDEδ.

  13. Feruloyl-CoA:monolignol transferase

    Energy Technology Data Exchange (ETDEWEB)

    Wilkerson, Curtis; Ralph, John; Withers, Saunia; Mansfield, Shawn D.

    2016-09-13

    The invention relates to nucleic acids encoding a feruloyl-CoA:monolignol transferase and the feruloyl-CoA:monolignol transferase enzyme that enables incorporation of monolignol ferulates, for example, including p-coumaryl ferulate, coniferyl ferulate, and sinapyl ferulate, into the lignin of plants.

  14. Feruloyl-CoA:monolignol transferase

    Energy Technology Data Exchange (ETDEWEB)

    Wilkerson, Curtis; Ralph, John; Withers, Saunia; Mansfield, Shawn D.

    2016-11-08

    The invention relates to nucleic acids encoding a feruloyl-CoA:monolignol transferase and the feruloyl-CoA:monolignol transferase enzyme that enables incorporation of monolignol ferulates, for example, including p-coumaryl ferulate, coniferyl ferulate, and sinapyl ferulate, into the lignin of plants.

  15. Glutathione transferases: a structural perspective.

    Science.gov (United States)

    Oakley, Aaron

    2011-05-01

    The glutathione transferases (GSTs) are one of the most important families of detoxifying enzymes in nature. The classic activity of the GSTs is conjugation of compounds with electrophilic centers to the tripeptide glutathione (GSH), but many other activities are now associated with GSTs, including steroid and leukotriene biosynthesis, peroxide degradation, double-bond cis-trans isomerization, dehydroascorbate reduction, Michael addition, and noncatalytic "ligandin" activity (ligand binding and transport). Since the first GST structure was determined in 1991, there has been an explosion in structural data across GSTs of all three families: the cytosolic GSTs, the mitochondrial GSTs, and the membrane-associated proteins in eicosanoid and glutathione metabolism (MAPEG family). In this review, the major insights into GST structure and function will be discussed.

  16. Cloning and Characterization of Farnesyl Diphosphate Synthase Gene Involved in Triterpenoids Biosynthesis from Poria cocos

    Directory of Open Access Journals (Sweden)

    Jianrong Wang

    2014-12-01

    Full Text Available Poria cocos (P. cocos has long been used as traditional Chinese medicine and triterpenoids are the most important pharmacologically active constituents of this fungus. Farnesyl pyrophosphate synthase (FPS is a key enzyme of triterpenoids biosynthesis. The gene encoding FPS was cloned from P. cocos by degenerate PCR, inverse PCR and cassette PCR. The open reading frame of the gene is 1086 bp in length, corresponding to a predicted polypeptide of 361 amino acid residues with a molecular weight of 41.2 kDa. Comparison of the P. cocos FPS deduced amino acid sequence with other species showed the highest identity with Ganoderma lucidum (74%. The predicted P. cocos FPS shares at least four conserved regions involved in the enzymatic activity with the FPSs of varied species. The recombinant protein was expressed in Pichia pastoris and purified. Gas chromatography analysis showed that the recombinant FPS could catalyze the formation of farnesyl diphosphate (FPP from geranyl diphosphate (GPP and isopentenyl diphosphate (IPP. Furthermore, the expression profile of the FPS gene and content of total triterpenoids under different stages of development and methyl jasmonate treatments were determined. The results indicated that there is a positive correlation between the activity of FPS and the amount of total triterpenoids produced in P. cocos.

  17. Cloning and characterization of farnesyl diphosphate synthase gene involved in triterpenoids biosynthesis from Poria cocos.

    Science.gov (United States)

    Wang, Jianrong; Li, Yangyuan; Liu, Danni

    2014-12-02

    Poria cocos (P. cocos) has long been used as traditional Chinese medicine and triterpenoids are the most important pharmacologically active constituents of this fungus. Farnesyl pyrophosphate synthase (FPS) is a key enzyme of triterpenoids biosynthesis. The gene encoding FPS was cloned from P. cocos by degenerate PCR, inverse PCR and cassette PCR. The open reading frame of the gene is 1086 bp in length, corresponding to a predicted polypeptide of 361 amino acid residues with a molecular weight of 41.2 kDa. Comparison of the P. cocos FPS deduced amino acid sequence with other species showed the highest identity with Ganoderma lucidum (74%). The predicted P. cocos FPS shares at least four conserved regions involved in the enzymatic activity with the FPSs of varied species. The recombinant protein was expressed in Pichia pastoris and purified. Gas chromatography analysis showed that the recombinant FPS could catalyze the formation of farnesyl diphosphate (FPP) from geranyl diphosphate (GPP) and isopentenyl diphosphate (IPP). Furthermore, the expression profile of the FPS gene and content of total triterpenoids under different stages of development and methyl jasmonate treatments were determined. The results indicated that there is a positive correlation between the activity of FPS and the amount of total triterpenoids produced in P. cocos.

  18. Cloning of the Arabidopsis WIGGUM gene identifies a role for farnesylation in meristem development

    Science.gov (United States)

    Ziegelhoffer, Eva C.; Medrano, Leonard J.; Meyerowitz, Elliot M.

    2000-01-01

    Control of cellular proliferation in plant meristems is important for maintaining the correct number and position of developing organs. One of the genes identified in the control of floral and apical meristem size and floral organ number in Arabidopsis thaliana is WIGGUM. In wiggum mutants, one of the most striking phenotypes is an increase in floral organ number, particularly in the sepals and petals, correlating with an increase in the width of young floral meristems. Additional phenotypes include reduced and delayed germination, delayed flowering, maturation, and senescence, decreased internode elongation, shortened roots, aberrant phyllotaxy of flowers, aberrant sepal development, floral buds that open precociously, and occasional apical meristem fasciation. As a first step in determining a molecular function for WIGGUM, we used positional cloning to identify the gene. DNA sequencing revealed that WIGGUM is identical to ERA1 (enhanced response to abscisic acid), a previously identified farnesyltransferase β-subunit gene of Arabidopsis. This finding provides a link between protein modification by farnesylation and the control of meristem size. Using in situ hybridization, we examined the expression of ERA1 throughout development and found it to be nearly ubiquitous. This extensive expression domain is consistent with the pleiotropic nature of wiggum mutants and highlights a broad utility for farnesylation in plant growth and development. PMID:10840062

  19. Nuclear receptor engineering based on novel structure activity relationships revealed by farnesyl pyrophosphate.

    Science.gov (United States)

    Goyanka, Ritu; Das, Sharmistha; Samuels, Herbert H; Cardozo, Timothy

    2010-11-01

    Nuclear receptors (NRs) comprise the second largest protein family targeted by currently available drugs, acting via specific ligand interactions within the ligand binding domain (LBD). Recently, farnesyl pyrophosphate (FPP) was shown to be a unique promiscuous NR ligand, activating a subset of NR family members and inhibiting wound healing in skin. The current study aimed at visualizing the unique basis of FPP interaction with multiple receptors in order to identify general structure-activity relationships that operate across the NR family. Docking of FPP to the 3D structures of the LBDs of a diverse set of NRs consistently revealed an electrostatic FPP pyrophosphate contact with an NR arginine conserved in the NR family, a hydrophobic farnesyl contact with NR helix-12 and a ligand binding pocket volume between 300 and 430 Å(3) as the minimal requirements for FPP activation of any NR. Lack of any of these structural features appears to render a given NR resistant to FPP activation. We used these structure-activity relationships to rationally design and successfully engineer several mutant human estrogen receptors that retain responsiveness to estradiol but no longer respond to FPP.

  20. VPS35 binds farnesylated N-Ras in the cytosol to regulate N-Ras trafficking

    Science.gov (United States)

    Wiener, Heidi; Su, Wenjuan; Liot, Caroline; Hancock, John F.

    2016-01-01

    Ras guanosine triphosphatases (GTPases) regulate signaling pathways only when associated with cellular membranes through their C-terminal prenylated regions. Ras proteins move between membrane compartments in part via diffusion-limited, fluid phase transfer through the cytosol, suggesting that chaperones sequester the polyisoprene lipid from the aqueous environment. In this study, we analyze the nature of the pool of endogenous Ras proteins found in the cytosol. The majority of the pool consists of farnesylated, but not palmitoylated, N-Ras that is associated with a high molecular weight (HMW) complex. Affinity purification and mass spectrographic identification revealed that among the proteins found in the HMW fraction is VPS35, a latent cytosolic component of the retromer coat. VPS35 bound to N-Ras in a farnesyl-dependent, but neither palmitoyl- nor guanosine triphosphate (GTP)–dependent, fashion. Silencing VPS35 increased N-Ras’s association with cytoplasmic vesicles, diminished GTP loading of Ras, and inhibited mitogen-activated protein kinase signaling and growth of N-Ras–dependent melanoma cells. PMID:27502489

  1. Functional characterization of the Xanthophyllomyces dendrorhous farnesyl pyrophosphate synthase and geranylgeranyl pyrophosphate synthase encoding genes that are involved in the synthesis of isoprenoid precursors.

    Directory of Open Access Journals (Sweden)

    Jennifer Alcaíno

    Full Text Available The yeast Xanthophyllomyces dendrorhous synthesizes the carotenoid astaxanthin, which has applications in biotechnology because of its antioxidant and pigmentation properties. However, wild-type strains produce too low amounts of carotenoids to be industrially competitive. Considering this background, it is indispensable to understand how the synthesis of astaxanthin is controlled and regulated in this yeast. In this work, the steps leading to the synthesis of the carotenoid precursor geranylgeranyl pyrophosphate (GGPP, C20 in X. dendrorhous from isopentenyl pyrophosphate (IPP, C5 and dimethylallyl pyrophosphate (DMAPP, C5 was characterized. Two prenyl transferase encoding genes, FPS and crtE, were expressed in E. coli. The enzymatic assays using recombinant E. coli protein extracts demonstrated that FPS and crtE encode a farnesyl pyrophosphate (FPP, C15 synthase and a GGPP-synthase, respectively. X. dendrorhous FPP-synthase produces geranyl pyrophosphate (GPP, C10 from IPP and DMAPP and FPP from IPP and GPP, while the X. dendrorhous GGPP-synthase utilizes only FPP and IPP as substrates to produce GGPP. Additionally, the FPS and crtE genes were over-expressed in X. dendrorhous, resulting in an increase of the total carotenoid production. Because the parental strain is diploid, the deletion of one of the alleles of these genes did not affect the total carotenoid production, but the composition was significantly altered. These results suggest that the over-expression of these genes might provoke a higher carbon flux towards carotenogenesis, most likely involving an earlier formation of a carotenogenic enzyme complex. Conversely, the lower carbon flux towards carotenogenesis in the deletion mutants might delay or lead to a partial formation of a carotenogenic enzyme complex, which could explain the accumulation of astaxanthin carotenoid precursors in these mutants. In conclusion, the FPS and the crtE genes represent good candidates to manipulate to

  2. Functional characterization of the Xanthophyllomyces dendrorhous farnesyl pyrophosphate synthase and geranylgeranyl pyrophosphate synthase encoding genes that are involved in the synthesis of isoprenoid precursors.

    Science.gov (United States)

    Alcaíno, Jennifer; Romero, Ignacio; Niklitschek, Mauricio; Sepúlveda, Dionisia; Rojas, María Cecilia; Baeza, Marcelo; Cifuentes, Víctor

    2014-01-01

    The yeast Xanthophyllomyces dendrorhous synthesizes the carotenoid astaxanthin, which has applications in biotechnology because of its antioxidant and pigmentation properties. However, wild-type strains produce too low amounts of carotenoids to be industrially competitive. Considering this background, it is indispensable to understand how the synthesis of astaxanthin is controlled and regulated in this yeast. In this work, the steps leading to the synthesis of the carotenoid precursor geranylgeranyl pyrophosphate (GGPP, C20) in X. dendrorhous from isopentenyl pyrophosphate (IPP, C5) and dimethylallyl pyrophosphate (DMAPP, C5) was characterized. Two prenyl transferase encoding genes, FPS and crtE, were expressed in E. coli. The enzymatic assays using recombinant E. coli protein extracts demonstrated that FPS and crtE encode a farnesyl pyrophosphate (FPP, C15) synthase and a GGPP-synthase, respectively. X. dendrorhous FPP-synthase produces geranyl pyrophosphate (GPP, C10) from IPP and DMAPP and FPP from IPP and GPP, while the X. dendrorhous GGPP-synthase utilizes only FPP and IPP as substrates to produce GGPP. Additionally, the FPS and crtE genes were over-expressed in X. dendrorhous, resulting in an increase of the total carotenoid production. Because the parental strain is diploid, the deletion of one of the alleles of these genes did not affect the total carotenoid production, but the composition was significantly altered. These results suggest that the over-expression of these genes might provoke a higher carbon flux towards carotenogenesis, most likely involving an earlier formation of a carotenogenic enzyme complex. Conversely, the lower carbon flux towards carotenogenesis in the deletion mutants might delay or lead to a partial formation of a carotenogenic enzyme complex, which could explain the accumulation of astaxanthin carotenoid precursors in these mutants. In conclusion, the FPS and the crtE genes represent good candidates to manipulate to favor

  3. Blocking farnesylation of the prelamin A variant in Hutchinson-Gilford progeria syndrome alters the distribution of A-type lamins

    Science.gov (United States)

    Wang, Yuexia; Ӧstlund, Cecilia; Choi, Jason C.; Swayne, Theresa C.; Gundersen, Gregg G.; Worman, Howard J.

    2012-01-01

    Mutations in the lamin A/C gene that cause Hutchinson-Gilford progeria syndrome lead to expression of a truncated, permanently farnesylated prelamin A variant called progerin. Blocking farnesylation leads to an improvement in the abnormal nuclear morphology observed in cells expressing progerin, which is associated with a re-localization of the variant protein from the nuclear envelope to the nuclear interior. We now show that a progerin construct that cannot be farnesylated is localized primarily in intranuclear foci and that its diffusional mobility is significantly greater than that of farnesylated progerin localized predominantly at the nuclear envelope. Expression of non-farnesylated progerin in transfected cells leads to a redistribution of lamin A and lamin C away from the nuclear envelope into intranuclear foci but does not significantly affect the localization of endogenous lamin B1 at nuclear envelope. There is a similar redistribution of lamin A and lamin C into intranuclear foci in transfected cells expressing progerin in which protein farnesylation is blocked by treatment with a protein farnesyltransferase inhibitor. Blocking farnesylation of progerin can lead to a redistribution of normal A-type lamins away from the inner nuclear envelope. This may have implications for using drugs that block protein prenylation to treat children with Hutchinson-Gilford progeria syndrome. These findings also provide additional evidence that A-type and B-type lamins can form separate microdomains within the nucleus. PMID:22895092

  4. Sigma-class glutathione transferases.

    Science.gov (United States)

    Flanagan, Jack U; Smythe, Mark L

    2011-05-01

    Mammalian cytosolic glutathione transferases (GSTs) can be grouped into seven classes. Of these, the sigma class is also widely distributed in nature, with isoforms found in both vertebrates and invertebrates. It contains examples of proteins that have evolved specialized functions, such as the cephalopod lens S-crystallins, the mammalian hematopoietic prostaglandin D(2) synthase, and the helminth 28-kDa antigen. In mammals, the sigma-class GST has both anti- and proinflammatory functions, depending on the type of immune response, and an immunomodulatory function is also associated with the enzyme from helminth parasites. In the fly, it is associated with a specific detoxication activity toward lipid oxidation products. Mice genetically depleted of the sigma-class GST, or transgenically overexpressing it, have provided insight into the physiological roles of the GST. Inhibitors of the mammalian enzyme developed by structure-based methods are effective in controlling allergic response. This review covers the structure, function, and pharmacology of vertebrate and invertebrate GSTs.

  5. Absence of progeria-like disease phenotypes in knock-in mice expressing a non-farnesylated version of progerin.

    Science.gov (United States)

    Yang, Shao H; Chang, Sandy Y; Ren, Shuxun; Wang, Yibin; Andres, Douglas A; Spielmann, H Peter; Fong, Loren G; Young, Stephen G

    2011-02-01

    Hutchinson-Gilford progeria syndrome (HGPS) is caused by a mutant prelamin A, progerin, that terminates with a farnesylcysteine. HGPS knock-in mice (Lmna(HG/+)) develop severe progeria-like disease phenotypes. These phenotypes can be ameliorated with a protein farnesyltransferase inhibitor (FTI), suggesting that progerin's farnesyl lipid is important for disease pathogenesis and raising the possibility that FTIs could be useful for treating humans with HGPS. Subsequent studies showed that mice expressing non-farnesylated progerin (Lmna(nHG/+) mice, in which progerin's carboxyl-terminal -CSIM motif was changed to -SSIM) also develop severe progeria, raising doubts about whether any treatment targeting protein prenylation would be particularly effective. We suspected that those doubts might be premature and hypothesized that the persistent disease in Lmna(nHG/+) mice could be an unanticipated consequence of the cysteine-to-serine substitution that was used to eliminate farnesylation. To test this hypothesis, we generated a second knock-in allele yielding non-farnesylated progerin (Lmna(csmHG)) in which the carboxyl-terminal -CSIM motif was changed to -CSM. We then compared disease phenotypes in mice harboring the Lmna(nHG) or Lmna(csmHG) allele. As expected, Lmna(nHG/+) and Lmna(nHG/nHG) mice developed severe progeria-like disease phenotypes, including osteolytic lesions and rib fractures, osteoporosis, slow growth and reduced survival. In contrast, Lmna(csmHG/+) and Lmna(csmHG/csmHG) mice exhibited no bone disease and displayed entirely normal body weights and survival. The frequencies of misshapen cell nuclei were lower in Lmna(csmHG/+) and Lmna(csmHG/csmHG) fibroblasts. These studies show that the ability of non-farnesylated progerin to elicit disease depends on the carboxyl-terminal mutation used to eliminate protein prenylation.

  6. Molecular Cloning and Characterisation of Farnesyl Pyrophosphate Synthase from Tripterygium wilfordii.

    Science.gov (United States)

    Zhao, Yu-Jun; Chen, Xin; Zhang, Meng; Su, Ping; Liu, Yu-Jia; Tong, Yu-Ru; Wang, Xiu-Juan; Huang, Lu-Qi; Gao, Wei

    2015-01-01

    Farnesylpyrophosphate synthase (FPS) catalyzes the biosynthesis of farnesyl pyrophosphate (FPP), which is an important precursor of sesquiterpenoids such as artemisinin and wilfordine. In the present study, we report the molecular cloning and characterization of two full-length cDNAs encoding FPSs from Tripterygium wilfordii (TwFPSs). TwFPSs maintained their capability to synthesise FPP in vitro when purified as recombinant proteins from E. coli. Consistent with the endogenous role of FPS in FPP biosynthesis, TwFPSs were highly expressed in T. wilfordii roots, and were up-regulated upon methyl jasmonate (MeJA) treatment. The global gene expression profiles suggested that the TwFPSs might play an important regulatory role interpenoid biosynthesis in T. wilfordii, laying the groundwork for the future study of the synthetic biology of natural terpene products.

  7. Lentiviral-Mediated Silencing of Farnesyl Pyrophosphate Synthase through RNA Interference in Mice

    Directory of Open Access Journals (Sweden)

    Jian Yang

    2015-01-01

    Full Text Available Farnesyl pyrophosphate synthase (FPPS plays a vital role in the mevalonate pathway and has been shown to be involved in hypertrophy and cardiovascular diseases. Lentivirus-mediated RNA interference (RNAi to knock down a gene of interest has become a promising new tool for the establishment of transgenic animals. The interfering fragment, named pLVT202, was chosen from cardiomyocytes tested in vitro and was microinjected into the perivitelline space of zygotes from C57BL/6J mice via a lentivirus vehicle; 20 were identified as carrying copies of the transgene using the polymerase chain reaction (PCR. Real-time PCR and western blotting analysis showed that FPPS was downregulated in multiple tissues in the transgenic mice. The transgenic mouse model provides a novel means of studying the gene function of FPPS.

  8. Two Eucommia farnesyl diphosphate synthases exhibit distinct enzymatic properties leading to end product preferences.

    Science.gov (United States)

    Kajiura, Hiroyuki; Suzuki, Nobuaki; Tokumoto, Yuji; Yoshizawa, Takuya; Takeno, Shinya; Fujiyama, Kazuhito; Kaneko, Yoshinobu; Matsumura, Hiroyoshi; Nakazawa, Yoshihisa

    2017-08-01

    Farnesyl diphosphate synthase (FPS) is an essential enzyme in the biosynthesis of prenyl precursors for the production of primary and secondary metabolites, including sterols, dolichols, carotenoids and ubiquinones, and for the modification of proteins. Here we identified and characterized two FPSs (EuFPS1 and EuFPS2) from the plant Eucommia ulmoides. The EuFPSs had seven highly conserved prenyltransferase-specific domains that are critical for activity. Complementation and biochemical analyses using bacterially produced recombinant EuFPS isoforms showed that the EuFPSs had FPP synthesis activities both in vivo and in vitro. In addition to the typical reaction mechanisms of FPS, EuFPSs utilized farnesyl diphosphate (FPP) as an allylic substrate and participated in further elongation of the isoprenyl chain, resulting in the synthesis of geranylgeranyl diphosphate. However, despite the high amino acid similarities between the two EuFPS isozymes, their specific activities, substrate preferences, and final reaction products were different. The use of dimethylallyl diphosphate (DMAPP) as an allylic substrate highlighted the differences between the two enzymes: depending on the pH, the metal ion cofactor, and the cofactor concentration, EuFPS2 accumulated geranyl diphosphate as an intermediate product at a constant rate, whereas EuFPS1 synthesized little geranyl diphosphate. The reaction kinetics of the EuFPSs demonstrated that isopentenyl diphosphate and DMAPP were used both as substrates and as inhibitors of EuFPS activity. Taken together, the results indicate that the biosynthesis of FPP is highly regulated by various factors indispensable for EuFPS reactions in plants. Copyright © 2017. Published by Elsevier B.V.

  9. Impact of Farnesylation Inhibitors on Survival in Hutchinson-Gilford Progeria Syndrome

    Science.gov (United States)

    Gordon, Leslie B.; Massaro, Joe; D'Agostino, Ralph B.; Campbell, Susan E.; Brazier, Joan; Brown, W. Ted; Kleinman, Monica E; Kieran, Mark W.

    2014-01-01

    Background Hutchinson-Gilford progeria syndrome is an ultra-rare segmental premature aging disease resulting in early death from heart attack or stroke. There is no approved treatment, but starting in 2007, several recent single arm clinical trials have administered inhibitors of protein farnesylation aimed at reducing toxicity of the disease-producing protein progerin. No study has assessed whether treatments influence patient survival. The key elements necessary for this analysis are a robust natural history of survival and comparison with a sufficiently large patient population that has been treated for a sufficient time period with disease-targeting medications. Methods and Results We generated survival Kaplan-Meier survival analyses for the largest untreated Hutchinson-Gilford progeria syndrome cohort to date. Mean survival was 14.6 years. Comparing survival for treated versus age-and-gender-matched untreated cohorts, hazard ratio was 0.13 (95% CI 0.04-0.37; P<0.001) with median follow-up of 5.3 years from time of treatment initiation. There were 21/43 deaths in untreated versus 5/43 deaths among treated subjects. Treatment increased mean survival by 1.6 years. Conclusions This study provides a robust untreated disease survival profile, which can be utilized for comparisons now and in the future to assess changes in survival with treatments for HGPS. The current comparisons estimating increased survival with protein farnesylation inhibitors provide the first evidence of treatments influencing survival for this fatal disease. Clinical Trial Registration Information www.clinicaltrials.gov. Indentifiers: NCT00425607, NCT00879034 and NCT00916747. PMID:24795390

  10. Roles for glutathione transferases in antioxidant recycling.

    Science.gov (United States)

    Dixon, David P; Steel, Patrick G; Edwards, Robert

    2011-08-01

    Uniquely among the plant glutathione transferases, two classes possess a catalytic cysteine capable of performing glutathione-dependent reductions. These are the dehydroascorbate reductases (DHARs) and the lambda-class glutathione transferases (GSTLs). Using immobilized GSTLs probed with crude plant extracts we have identified flavonols as high affinity ligands and subsequently demonstrated a novel glutathione-dependent role for these enzymes in recycling oxidized quercetin. By comparing the activities of DHARs and GSTLs we now propose a unified catalytic mechanism that suggests oxidized anthocyanidins and tocopherols may be alternative polyphenolic substrates of GSTLs.

  11. Enlarging the scope of cell penetrating prenylated peptides to include farnesylated “CAAX” box sequences and diverse cell types

    Science.gov (United States)

    Ochocki, Joshua D.; Igbavboa, Urule; Wood, W. Gibson; Wattenberg, Elizabeth V.; Distefano, Mark D.

    2010-01-01

    Protein prenylation is a post-translational modification that is present in a large number of proteins; it has been proposed to be responsible for membrane association and protein-protein interactions which contribute to its role in signal transduction pathways. Research has been aimed at inhibiting prenylation with farnesyltransferase inhibitors (FTIs) based on the finding that the farnesylated protein Ras is implicated in 30% of human cancers. Despite numerous studies on the enzymology of prenylation in vitro, many questions remain about the process of prenylation as it occurs in living cells. Here we describe the preparation of a series of farnesylated peptides that contain sequences recognized by protein farnesyltransferase. Using a combination of flow cytometry and confocal microscopy, we show that these peptides enter a variety of different cell types. A related peptide where the farnesyl group has been replaced by a disulfide-linked decyl group is also shown to be able to efficiently enter cells. These results highlight the applicability of these peptides as a platform for further study of protein prenylation and subsequent processing in live cells. PMID:20584014

  12. Plant glutathione transferase-mediated stress tolerance

    NARCIS (Netherlands)

    Nianiou-Obeidat, Irini; Madesis, Panagiotis; Kissoudis, Christos; Voulgari, Georgia; Chronopoulou, Evangelia; Tsaftaris, Athanasios; Labrou, Nikolaos E.

    2017-01-01

    Plant glutathione transferases (EC 2.5.1.18, GSTs) are an ancient, multimember and diverse enzyme class. Plant GSTs have diverse roles in plant development, endogenous metabolism, stress tolerance, and xenobiotic detoxification. Their study embodies both fundamental aspects and agricultural

  13. [Structure and functions of glutathione transferases].

    Science.gov (United States)

    Fedets, O M

    2014-01-01

    Data about classification, nomenclature, structure, substrate specificity and role of many glutathione transferase's isoenzymes in cell functions have been summarised. The enzyme has been discovered more than 50 years ago. This family of proteins is updated continuously. It has very different composition and will have demand for system analysis for many years.

  14. 21 CFR 862.1535 - Ornithine carbamyl transferase test system.

    Science.gov (United States)

    2010-04-01

    ... carbamyl transferase (OCT) in serum. Ornithine carbamyl transferase measurements are used in the diagnosis and treatment of liver diseases, such as infectious hepatitis, acute cholecystitis (inflammation of the gall bladder), cirrhosis, and liver metastases. (b) Classification. Class I (general controls...

  15. Crystallization and preliminary neutron diffraction experiment of human farnesyl pyrophosphate synthase complexed with risedronate.

    Science.gov (United States)

    Yokoyama, Takeshi; Ostermann, Andreas; Mizuguchi, Mineyuki; Niimura, Nobuo; Schrader, Tobias E; Tanaka, Ichiro

    2014-04-01

    Nitrogen-containing bisphosphonates (N-BPs), such as risedronate and zoledronate, are currently used as a clinical drug for bone-resorption diseases and are potent inhibitors of farnesyl pyrophosphate synthase (FPPS). X-ray crystallographic analyses of FPPS with N-BPs have revealed that N-BPs bind to FPPS with three magnesium ions and several water molecules. To understand the structural characteristics of N-BPs bound to FPPS, including H atoms and hydration by water, neutron diffraction studies were initiated using BIODIFF at the Heinz Maier-Leibnitz Zentrum (MLZ). FPPS-risedronate complex crystals of approximate dimensions 2.8 × 2.5 × 1.5 mm (∼3.5 mm(3)) were obtained by repeated macro-seeding. Monochromatic neutron diffraction data were collected to 2.4 Å resolution with 98.4% overall completeness. Here, the first successful neutron data collection from FPPS in complex with N-BPs is reported.

  16. Farnesyl pyrophosphate synthase is the molecular target of nitrogen-containing bisphosphonates.

    Science.gov (United States)

    van Beek, E; Pieterman, E; Cohen, L; Löwik, C; Papapoulos, S

    1999-10-14

    Bisphosphonates (Bps), inhibitors of osteoclastic bone resorption, are used in the treatment of skeletal disorders. Recent evidence indicated that farnesyl pyrophosphate (FPP) synthase and/or isopentenyl pyrophosphate (IPP) isomerase is the intracellular target(s) of bisphosphonate action. To examine which enzyme is specifically affected, we determined the effect of different Bps on incorporation of [(14)C]mevalonate (MVA), [(14)C]IPP, and [(14)C]dimethylallyl pyrophosphate (DMAPP) into polyisoprenyl pyrophosphates in a homogenate of bovine brain. HPLC analysis revealed that the three intermediates were incorporated into FPP and geranylgeranyl pyrophosphate (GGPP). In contrast to clodronate, the nitrogen-containing Bps (NBps), alendronate, risedronate, olpadronate, and ibandronate, completely blocked FPP and GGPP formation and induced in incubations with [(14)C]MVA a 3- to 5-fold increase in incorporation of label into IPP and/or DMAPP. Using a method that could distinguish DMAPP from IPP on basis of their difference in stability in acid, we found that none of the NBps affected the conversion of [(14)C]IPP into DMAPP, catalyzed by IPP isomerase, excluding this enzyme as target of NBp action. On the basis of these and our previous findings, we conclude that none of the enzymes up- or downstream of FPP synthase are affected by NBps, and FPP synthase is, therefore, the exclusive molecular target of NBp action.

  17. Geosmin biosynthesis. Streptomyces coelicolor germacradienol/germacrene D synthase converts farnesyl diphosphate to geosmin.

    Science.gov (United States)

    Jiang, Jiaoyang; He, Xiaofei; Cane, David E

    2006-06-28

    Geosmin is responsible for the characteristic odor of moist soil. Incubation of recombinant germacradienol synthase, encoded by the SCO6073 (SC9B1.20) gene of the Gram-positive soil bacterium Streptomyces coelicolor, with farnesyl diphosphate (2, FPP) in the presence of Mg2+ gave a mixture of (4S,7R)-germacra-1(10)E,5E-diene-11-ol (3) (74%), (-)-(7S)-germacrene D (4) (10%), geosmin (1) (13%), and a hydrocarbon, tentatively assigned the structure of octalin 5 (3%). Individual incubations of recombinant germacradienol synthase with [1,1-2H2]FPP (2a), (1R)-[1-2H]-FPP (2b), and (1S)-[1-2H]-FPP (2c), as well as with FPP (2) in D2O, and GC-MS analysis of the resulting deuterated products supported a mechanism of geosmin formation involving proton-initiated cyclization and retro-Prins fragmentation of the initially formed germacradienol to give intermediate 5, followed by protonation of 5, 1,2-hydride shift, and capture of water.

  18. Cloning and characterization of farnesyl pyrophosphate synthase from the highly branched isoprenoid producing diatom Rhizosolenia setigera.

    Science.gov (United States)

    Ferriols, Victor Marco Emmanuel N; Yaginuma, Ryoko; Adachi, Masao; Takada, Kentaro; Matsunaga, Shigeki; Okada, Shigeru

    2015-05-21

    The diatom Rhizosolenia setigera Brightwell produces highly branched isoprenoid (HBI) hydrocarbons that are ubiquitously present in marine environments. The hydrocarbon composition of R. setigera varies between C25 and C30 HBIs depending on the life cycle stage with regard to auxosporulation. To better understand how these hydrocarbons are biosynthesized, we characterized the farnesyl pyrophosphate (FPP) synthase (FPPS) enzyme of R. setigera. An isolated 1465-bp cDNA clone contained an open reading frame spanning 1299-bp encoding a protein with 432 amino acid residues. Expression of the RsFPPS cDNA coding region in Escherichia coli produced a protein that exhibited FPPS activity in vitro. A reduction in HBI content from diatoms treated with an FPPS inhibitor, risedronate, suggested that RsFPPS supplies precursors for HBI biosynthesis. Product analysis by gas chromatography-mass spectrometry also revealed that RsFPPS produced small amounts of the cis-isomers of geranyl pyrophosphate and FPP, candidate precursors for the cis-isomers of HBIs previously characterized. Furthermore, RsFPPS gene expression at various life stages of R. setigera in relation to auxosporulation were also analyzed. Herein, we present data on the possible role of RsFPPS in HBI biosynthesis, and it is to our knowledge the first instance that an FPPS was cloned and characterized from a diatom.

  19. Positive selection and functional divergence of farnesyl pyrophosphate synthase genes in plants.

    Science.gov (United States)

    Qian, Jieying; Liu, Yong; Chao, Naixia; Ma, Chengtong; Chen, Qicong; Sun, Jian; Wu, Yaosheng

    2017-02-04

    Farnesyl pyrophosphate synthase (FPS) belongs to the short-chain prenyltransferase family, and it performs a conserved and essential role in the terpenoid biosynthesis pathway. However, its classification, evolutionary history, and the forces driving the evolution of FPS genes in plants remain poorly understood. Phylogeny and positive selection analysis was used to identify the evolutionary forces that led to the functional divergence of FPS in plants, and recombinant detection was undertaken using the Genetic Algorithm for Recombination Detection (GARD) method. The dataset included 68 FPS variation pattern sequences (2 gymnosperms, 10 monocotyledons, 54 dicotyledons, and 2 outgroups). This study revealed that the FPS gene was under positive selection in plants. No recombinant within the FPS gene was found. Therefore, it was inferred that the positive selection of FPS had not been influenced by a recombinant episode. The positively selected sites were mainly located in the catalytic center and functional areas, which indicated that the 98S and 234D were important positively selected sites for plant FPS in the terpenoid biosynthesis pathway. They were located in the FPS conserved domain of the catalytic site. We inferred that the diversification of FPS genes was associated with functional divergence and could be driven by positive selection. It was clear that protein sequence evolution via positive selection was able to drive adaptive diversification in plant FPS proteins. This study provides information on the classification and positive selection of plant FPS genes, and the results could be useful for further research on the regulation of triterpenoid biosynthesis.

  20. Metabolism of farnesyl diphosphate in tobacco BY-2 cells treated with squalestatin.

    Science.gov (United States)

    Hartmann, M A; Wentzinger, L; Hemmerlin, A; Bach, T J

    2000-12-01

    Plant isoprenoids represent a large group of compounds with a wide range of physiological functions. In the cytosol, isoprenoids are synthesized via the classical acetate/mevalonate pathway. In this pathway, farnesyl diphosphate (FPP) occupies a central position, from which isoprene units are dispatched to the different classes of isoprenoids, with sterols as the major end products. The present work deals with effects of squalestatin (SQ) on the metabolism of FPP in proliferating and synchronized cultured tobacco cv. Bright Yellow-2 cells. SQ is a potent inhibitor of squalene synthase (SQS), the first committed enzyme in the sterol pathway. At nanomolar concentrations, SQ severely impaired cell growth and sterol biosynthesis, as attested by the rapid decrease in SQS activity. At the same time, it triggered a several-fold increase in both the enzymic activity and mRNA levels of 3-hydroxy-3-methylglutaryl CoA reductase. When SQ was added to cells synchronized by aphidicolin treatment, it was found to block the cell cycle at the end of G(1) phase, but no cell death was induced. Tobacco cells were also fed exogenous tritiated trans-trans farnesol, the allylic alcohol derived from FPP, in the presence and absence of SQ. Evidence is presented that this compound was incorporated into sterols and ubiquinone Q(10). In the presence of SQ, the sterol pathway was inhibited, but no increase in the radioactivity of ubiquinone was observed, suggesting that this metabolic channel was already saturated under normal conditions.

  1. Glutathione transferases as targets for cancer therapy.

    Science.gov (United States)

    Ruzza, Paolo; Rosato, Antonio; Rossi, Carlo Riccardo; Floreani, Maura; Quintieri, Luigi

    2009-09-01

    Besides catalyzing the inactivation of various electrophile-producing anticancer agents via conjugation to the tripeptide glutathione, some cytosolic proteins belonging to the glutathione transferase (formerly glutatione-S-transferase; GST) superfamily are emerging as negative modulators of stress/drug-induced cell apoptosis through the interaction with specific signaling kinases. In addition, several data link the overexpression of some GSTs, in particular GSTP1-1, to both natural and acquired resistance to various structurally unrelated anticancer drugs. Tumor overexpression of these proteins has provided a rationale for the search of GST inhibitors and GST-activated cytotoxic prodrugs. In the present review we discuss the current structural and pharmacological knowledge of both types of GST-targeting compounds.

  2. Purification and characterization of the Oligosaccharyl transferase

    Energy Technology Data Exchange (ETDEWEB)

    Kapoor, T.M.

    1990-11-01

    Oligosaccharyl transferase was characterized to be a glycoprotein with at least one saccharide unit that had a D-manno or D- glucopyranose configuration with unmodified hydroxy groups at C-3, C-4 and C-6, using a Concanavalin A affinity column. This afforded a 100 fold increase in the transferase purity in the solubilized microsomal sample and also removed over 90% of the microsomal proteins (the cytosolic ones being removed before solubilization). The detergent, N,N-Dimethyldodecylamine N-oxide (LDAO) was used for solubilization and it yielded a system compatible with the assay and the purification steps. An efficient method for detergent extraction without dilution of sample or protein precipitation was also developed.

  3. Clomazone Does Not Inhibit the Conversion of Isopentenyl Pyrophosphate to Geranyl, Farnesyl, or Geranylgeranyl Pyrophosphate in Vitro 1

    Science.gov (United States)

    Croteau, Rodney

    1992-01-01

    Clomazone, an herbicide that reduces the levels of leaf carotenoids and chlorophylls, is thought to act by inhibiting isopentenyl pyrophosphate isomerase or the prenyltransferases responsible for the synthesis of geranylgeranyl pyrophosphate. Cell-free extracts prepared from the oil glands of common sage (Salvia officinalis) are capable of converting isopentenyl pyrophosphate to geranylgeranyl pyrophosphate. Clomazone at 250 micromolar (a level that produced leaf bleaching) had no detectable effect on the activity of the relevant enzymes (isopentenyl pyrophosphate isomerase and the three prenyltransferases, geranyl, farnesyl, and geranylgeranyl pyrophosphate synthases). Thus, inhibition of geranylgeranyl pyrophosphate biosynthesis does not appear to be the mode of action of this herbicide. PMID:16668824

  4. Clomazone does not inhibit the conversion of isopentenyl pyrophosphate to geranyl, farnesyl, or geranylgeranyl pyrophosphate in vitro.

    Science.gov (United States)

    Croteau, R

    1992-04-01

    Clomazone, an herbicide that reduces the levels of leaf carotenoids and chlorophylls, is thought to act by inhibiting isopentenyl pyrophosphate isomerase or the prenyltransferases responsible for the synthesis of geranylgeranyl pyrophosphate. Cell-free extracts prepared from the oil glands of common sage (Salvia officinalis) are capable of converting isopentenyl pyrophosphate to geranylgeranyl pyrophosphate. Clomazone at 250 micromolar (a level that produced leaf bleaching) had no detectable effect on the activity of the relevant enzymes (isopentenyl pyrophosphate isomerase and the three prenyltransferases, geranyl, farnesyl, and geranylgeranyl pyrophosphate synthases). Thus, inhibition of geranylgeranyl pyrophosphate biosynthesis does not appear to be the mode of action of this herbicide.

  5. SIKLODEKSTRIN GLIKOSIL TRANSFERASE DAN PEMANFAATANNYA DALAM INDUSTRI [Cyclodextrin Glycosyl Transferase and its application in industries

    Directory of Open Access Journals (Sweden)

    Budiasih Wahyuntari

    2005-12-01

    Full Text Available Cyclodextrin glycosyl transferase (CGT-ase is mainly produced by Bacilli. Systematical name of the enzyme is E.C. 2.4.1.19 a-1,4 glucan-4-glycosyl transferase. The enzyme catalyzes hydrolysis of starch intramolecular, and intermolecular transglycosylation of a-1,4, glucan chains. Cyclodextrins are a-1,4 linked cyclic oligosaccharides resulting from enzymatic degradation of starch by cyclodextrin glycosyl transferase through untramolecular transglycosylation. The major cyclodextrins are made up of 6, 7 and 8 glucopyranose units which are known as a-, b-, and y-cyclodextrin. All CGT-ase catalyze three kinds of cyclodextrins, the proportion of the cyclodextrins depends on the enzyme source and reaction conditions. The intermolecular transglycosylation ability of the enzyme has been applied in transfering glycosyl residues into suitable acceptor. Transglycosylation by the enzymes have been tested to improve solubility of some flavonoids and to favor precipitation ci some glycosides.

  6. Glutathione S-transferases in pediatric cancer

    Directory of Open Access Journals (Sweden)

    Wen eLuo

    2011-10-01

    Full Text Available The glutathione S-transferases (GSTs are a family of ubiquitously-expressed polymorphic enzymes important for detoxifying endogenous and exogenous compounds. In addition to their classic activity of detoxification by conjugation of compounds with glutathione, many other functions are now found to be associated with GSTs. The associations between GST polymorphisms/functions and human disease susceptibility or treatment outcome, mostly in adults, have been extensively studied and reviewed. This mini review focuses on studies related to GST epidemiology and functions related to pediatric cancer. Opportunities to exploit GST in pediatric cancer therapy are also discussed.

  7. Antibodies with thiol-S-transferase activity

    Energy Technology Data Exchange (ETDEWEB)

    Fan, E.; Oei, Yoko; Sweet, E.; Uno, Tetsuo; Schultz, P.G. [Univ. of California, Berkeley, CA (United States)

    1996-06-12

    A major detoxification pathway used by aerobic organisms involves the conjugation of the tripeptide glutathione (GSH) to the electrophilic center of toxic substances. This reaction is catalyzed by a class of enzymes referred to as the glutathione S-transferases (GST) (EC 2.5.1.18). These enzymes activate the cysteine thiol group of GSH for nucleophilic addition to a variety of substrates, including aryl halides, {alpha}{beta}-unsaturated aldehydes and ketones, and epoxides. Despite the availability of X-ray crystal structures, the mechanism whereby glutathione transferases catalyze these addition reactions remains unclear. In order to gain a greater understanding of this important biological transformation, as well as to generate new detoxification catalysts, we have asked whether antibodies can be generated that catalyze similar nucleophilic addition reactions. Our initial efforts focused on the addition reaction of thiol nucleophiles to the nitro-substituted styrene derivative 1. The ratio of k{sub cat}/K{sub m} reported for the reaction of the isozyme 4-4` of rat liver GST with the good substance, 1-chloro-2,4-dinitrobenzene, is approximately 10{sup 4} M{sup -1} s{sup -1} compared to a calculated pseudo-first-order rate constant for the uncatalyzed reaction of approximately 3 x 10{sup -2} s{sup -1} (60 mM GSH, pH = 80). These comparisons suggest that with further improvements in hapten design, catalytic antibodies may prove a good source of detoxification catalysts. 19 refs., 1 fig.

  8. Blocking protein farnesylation improves nuclear shape abnormalities in keratinocytes of mice expressing the prelamin A variant in Hutchinson-Gilford progeria syndrome.

    Science.gov (United States)

    Wang, Yuexia; Ostlund, Cecilia; Worman, Howard J

    2010-01-01

    Hutchinson-Gilford progeria syndrome (HGPS) is an accelerated aging disorder caused by mutations in LMNA leading to expression of a truncated prelamin A variant termed progerin. Whereas a farnesylated polypeptide is normally removed from the carboxyl-terminus of prelamin A during endoproteolytic processing to lamin A, progerin lacks the cleavage site and remains farnesylated. Cultured cells from human subjects with HGPS and genetically modified mice expressing progerin have nuclear morphological abnormalities, which are reversed by inhibitors of protein farnesylation. In addition, treatment with protein farnesyltransferase inhibitors improves whole animal phenotypes in mouse models of HGPS. However, improvement in nuclear morphology in tissues after treatment of animals has not been demonstrated. We therefore treated transgenic mice that express progerin in epidermis with the protein farnesyltransferase inhibitor FTI-276 or a combination of pravastatin and zoledronate to determine if they reversed nuclear morphological abnormalities in tissue. Immunofluorescence microscopy and "blinded" electron microscopic analysis demonstrated that systemic administration of FTI-276 or pravastatin plus zoledronate significantly improved nuclear morphological abnormalities in keratinocytes of transgenic mice. These results show that pharmacological blockade of protein prenylation reverses nuclear morphological abnormalities that occur in HGPS in vivo. They further suggest that skin biopsy may be useful to determine if protein farnesylation inhibitors are exerting effects in subjects with HGPS in clinical trials.

  9. Structure of human farnesyl pyrophosphate synthase in complex with an aminopyridine bisphosphonate and two molecules of inorganic phosphate

    Energy Technology Data Exchange (ETDEWEB)

    Park, Jaeok [McGill University, 3655 Promenade Sir William Osler, Montreal, QC H3G 1Y6 (Canada); Lin, Yih-Shyan [McGill University, 801 Rue Sherbrooke Ouest, Montreal, QC H3A 0B8 (Canada); Tsantrizos, Youla S. [McGill University, 3655 Promenade Sir William Osler, Montreal, QC H3G 1Y6 (Canada); McGill University, 801 Rue Sherbrooke Ouest, Montreal, QC H3A 0B8 (Canada); McGill University, 3649 Promenade Sir William Osler, Montreal, QC H3G 0B1 (Canada); Berghuis, Albert M., E-mail: albert.berghuis@mcgill.ca [McGill University, 3655 Promenade Sir William Osler, Montreal, QC H3G 1Y6 (Canada); McGill University, 3649 Promenade Sir William Osler, Montreal, QC H3G 0B1 (Canada); McGill University, 3775 Rue University, Montreal, QC H3A 2B4 (Canada)

    2014-02-19

    A co-crystal structure of human farnesyl pyrophosphate synthase in complex with an aminopyridine bisphosphonate, YS0470, and two molecules of inorganic phosphate has been determined. The identity of the phosphate ligands was confirmed by anomalous diffraction data. Human farnesyl pyrophosphate synthase (hFPPS) produces farnesyl pyrophos@@phate, an isoprenoid essential for a variety of cellular processes. The enzyme has been well established as the molecular target of the nitrogen-containing bisphosphonates (N-BPs), which are best known for their antiresorptive effects in bone but are also known for their anticancer properties. Crystal structures of hFPPS in ternary complexes with a novel bisphosphonate, YS0470, and the secondary ligands inorganic phosphate (P{sub i}), inorganic pyrophosphate (PP{sub i}) and isopentenyl pyrophosphate (IPP) have recently been reported. Only the co-binding of the bisphosphonate with either PP{sub i} or IPP resulted in the full closure of the C-@@terminal tail of the enzyme, a conformational change that is required for catalysis and that is also responsible for the potent in vivo efficacy of N-BPs. In the present communication, a co-crystal structure of hFPPS in complex with YS0470 and two molecules of P{sub i} is reported. The unusually close proximity between these ligands, which was confirmed by anomalous diffraction data, suggests that they interact with one another, with their anionic charges neutralized in their bound state. The structure also showed the tail of the enzyme to be fully disordered, indicating that simultaneous binding of two P{sub i} molecules with a bisphosphonate cannot induce the tail-closing conformational change in hFPPS. Examination of homologous FPPSs suggested that this ligand-dependent tail closure is only conserved in the mammalian proteins. The prevalence of P{sub i}-bound hFPPS structures in the PDB raises a question regarding the in vivo relevance of P{sub i} binding to the function of the enzyme.

  10. Glutathione S-transferases as risk factors in prostate cancer

    DEFF Research Database (Denmark)

    Autrup, Judith; Thomassen, L.H.; Olsen, J.H.

    1999-01-01

    Glutathione S-transferases are enzymes involved in the metabolism of carcinogens and in the defence against reactive oxygen species. Genetic polymorphisms have been detected in glutathione S-transferases M1, T1 and P1, and some of these polymorphisms have been associated with an increased risk of...

  11. Effects of Overexpression of the Endogenous Farnesyl Diphosphate Synthase on the Artemisinin Content in Artemisia annua L.

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Artemisinin Is a novel effective antimalarial drug extracted from the medicinal plant Artemisia annua L. Owing to the tight market and low yield of artemislnin, there is great interest in enhancing the production of artemisinin.In the present study, farnesyl dlphosphate synthase (FPS) was overexpressed in high-yield A. annua to increase the artemislnin content. The FPS activity in transgenic A. annua was two- to threefold greater than that in non-transgenic A. annua. The highest artemisinin content in transgenic A. annua was approximately 0.9% (dry weight), which was 34.4% higher than that in non-transgenic A. annua. The results demonstrate the regulatory role of FPS in artemisinin biosynthesis.

  12. Solid-phase synthesis of Biotin-S-Farnesyl-L-Cysteine, a surrogate substrate for isoprenylcysteine Carboxylmethyltransferase (ICMT).

    Science.gov (United States)

    Stevenson, Graeme I; Yong, Sarah; Fechner, Gregory A; Neve, Juliette; Lock, Aaron; Avery, Vicky M

    2013-10-15

    Inhibition of isoprenylcysteine Carboxylmethyltransferase (ICMT) is of particular interest as a potential target for the development of cancer chemotherapeutic agents. Screening for inhibitors of ICMT utilises a scintillation proximity assay (SPA) in which Biotin-S-Farnesyl-L-Cysteine (BFC) acts as a surrogate substrate. A solid-phase synthesis protocol for the preparation of BFC using 2-chlorotrityl chloride resin as a solid support has been developed to provide sufficient supply of BFC for high throughput screening (HTS) and subsequent chemistry campaigns to target inhibitors of ICMT. The BFC prepared by this method can be produced quickly on large scale and is stable when stored at -20 °C as a solid, in solution, or on the resin.

  13. The subcellular localization of periwinkle farnesyl diphosphate synthase provides insight into the role of peroxisome in isoprenoid biosynthesis.

    Science.gov (United States)

    Thabet, Insaf; Guirimand, Grégory; Courdavault, Vincent; Papon, Nicolas; Godet, Stéphanie; Dutilleul, Christelle; Bouzid, Sadok; Giglioli-Guivarc'h, Nathalie; Clastre, Marc; Simkin, Andrew J

    2011-11-15

    Farnesyl diphosphate (FPP) synthase (FPS: EC.2.5.1.1, EC.2.5.1.10) catalyzes the formation of FPP from isopentenyl diphosphate and dimethylallyl diphosphate via two successive condensation reactions. A cDNA designated CrFPS, encoding a protein showing high similarities with trans-type short FPS isoforms, was isolated from the Madagascar periwinkle (Catharanthus roseus). This cDNA was shown to functionally complement the lethal FPS deletion mutant in the yeast Saccharomyces cerevisiae. At the subcellular level, while short FPS isoforms are usually described as cytosolic proteins, we showed, using transient transformations of C. roseus cells with yellow fluorescent protein-fused constructs, that CrFPS is targeted to peroxisomes. This finding is discussed in relation to the subcellular distribution of FPS isoforms in plants and animals and opens new perspectives towards the understanding of isoprenoid biosynthesis.

  14. Synthesis, Properties and Applications of Diazotrifluropropanoyl-Containing Photoactive Analogues of Farnesyl Diphosphate Containing Modified Linkages for Enhanced Stability

    Science.gov (United States)

    Hovlid, Marisa L.; Edelstein, Rebecca L.; Henry, Olivier; Ochocki, Joshua; DeGraw, Amanda; Lenevich, Stepan; Talbot, Trista; Young, Victor G.; Hruza, Alan W.; Lopez-Gallego, Fernando; Labello, Nicholas P.; Strickland, Corey L.; Schmidt-Dannert, Claudia; Distefano, Mark D.

    2009-01-01

    Photoactive analogues of farnesyl diphosphate (FPP) are useful probes in studies of enzymes that employ this molecule as a substrate. Here, we describe the preparation and properties of two new FPP analogues that contain diazotrifluoropropionyl photophores linked to geranyl diphosphate via amide or ester linkages. The amide-linked analogue (3) was synthesized in 32P-labeled form from geraniol in 7 steps. Experiments with Saccharomyces cerevisiae protein farnesyltransferase (ScPFTase) showed that 3 is an alternative substrate for the enzyme. Photolysis experiments with [32P]3 demonstrate that this compound labels the β-subunits of both farnesyl- and geranylgeranyltransferase (types 1 and 2). However, the amide-linked probe 3 undergoes a rearrangement to a photochemically unreactive isomeric triazolone upon long term storage making it inconvenient to use. To address this stability issue, the ester-linked analogue 4 was prepared in 6 steps from geraniol. Computational analysis and X-ray crystallographic studies suggest that 4 binds to PFTase in a similar fashion as FPP. Compound 4 is also an alternative substrate for PFTase and a 32P-labeled form selectively photocrosslinks the β-subunit of ScPFTase as well as E. coli farnesyldiphosphate synthase and a germacrene-producing sesquiterpene synthase from Nostoc sp. strain PCC7120 (a cyanobacterial source). Finally, nearly exclusive labeling of ScPFTase in crude E. coli extract was observed, suggesting that [32P]4 manifests significant selectivity and should hence be useful for identifying novel FPP utilizing enzymes in crude protein preparations. PMID:19954434

  15. Structural and thermodynamic basis of the inhibition of Leishmania major farnesyl diphosphate synthase by nitrogen-containing bisphosphonates

    Energy Technology Data Exchange (ETDEWEB)

    Aripirala, Srinivas [Johns Hopkins University, 725 North Wolfe Street WBSB 605, Baltimore, MD 21210 (United States); Gonzalez-Pacanowska, Dolores [López-Neyra Institute of Parasitology and Biomedicine, 18001 Granada (Spain); Oldfield, Eric [University of Illinois at Urbana-Champaign, Urbana, IL 61801 (United States); Kaiser, Marcel [University of Basel, Petersplatz 1, CH-4003 Basel (Switzerland); Amzel, L. Mario, E-mail: mamzel@jhmi.edu [Johns Hopkins University School of Medicine, 725 N. Wolfe Street WBSB 604, Baltimore, MD 21205 (United States); Gabelli, Sandra B., E-mail: mamzel@jhmi.edu [Johns Hopkins University School of Medicine, 725 N. Wolfe Street WBSB 604, Baltimore, MD 21205 (United States); Johns Hopkins University School of Medicine, Baltimore, MD 21205 (United States); Johns Hopkins University, 725 North Wolfe Street WBSB 605, Baltimore, MD 21210 (United States)

    2014-03-01

    Structural insights into L. major farnesyl diphosphate synthase, a key enzyme in the mevalonate pathway, are described. Farnesyl diphosphate synthase (FPPS) is an essential enzyme involved in the biosynthesis of sterols (cholesterol in humans and ergosterol in yeasts, fungi and trypanosomatid parasites) as well as in protein prenylation. It is inhibited by bisphosphonates, a class of drugs used in humans to treat diverse bone-related diseases. The development of bisphosphonates as antiparasitic compounds targeting ergosterol biosynthesis has become an important route for therapeutic intervention. Here, the X-ray crystallographic structures of complexes of FPPS from Leishmania major (the causative agent of cutaneous leishmaniasis) with three bisphosphonates determined at resolutions of 1.8, 1.9 and 2.3 Å are reported. Two of the inhibitors, 1-(2-hydroxy-2,2-diphosphonoethyl)-3-phenylpyridinium (300B) and 3-butyl-1-(2,2-diphosphonoethyl)pyridinium (476A), co-crystallize with the homoallylic substrate isopentenyl diphosphate (IPP) and three Ca{sup 2+} ions. A third inhibitor, 3-fluoro-1-(2-hydroxy-2,2-diphosphonoethyl)pyridinium (46I), was found to bind two Mg{sup 2+} ions but not IPP. Calorimetric studies showed that binding of the inhibitors is entropically driven. Comparison of the structures of L. major FPPS (LmFPPS) and human FPPS provides new information for the design of bisphosphonates that will be more specific for inhibition of LmFPPS. The asymmetric structure of the LmFPPS–46I homodimer indicates that binding of the allylic substrate to both monomers of the dimer results in an asymmetric dimer with one open and one closed homoallylic site. It is proposed that IPP first binds to the open site, which then closes, opening the site on the other monomer, which closes after binding the second IPP, leading to the symmetric fully occupied FPPS dimer observed in other structures.

  16. The Early-Acting Peroxin PEX19 Is Redundantly Encoded, Farnesylated, and Essential for Viability in Arabidopsis thaliana.

    Directory of Open Access Journals (Sweden)

    Margaret M McDonnell

    Full Text Available Peroxisomes are single-membrane bound organelles that are essential for normal development in plants and animals. In mammals and yeast, the peroxin (PEX proteins PEX3 and PEX19 facilitate the early steps of peroxisome membrane protein (PMP insertion and pre-peroxisome budding from the endoplasmic reticulum. The PEX3 membrane protein acts as a docking site for PEX19, a cytosolic chaperone for PMPs that delivers PMPs to the endoplasmic reticulum or peroxisomal membrane. PEX19 is farnesylated in yeast and mammals, and we used immunoblotting with prenylation mutants to show that PEX19 also is fully farnesylated in wild-type Arabidopsis thaliana plants. We examined insertional alleles disrupting either of the two Arabidopsis PEX19 isoforms, PEX19A or PEX19B, and detected similar levels of PEX19 protein in the pex19a-1 mutant and wild type; however, PEX19 protein was nearly undetectable in the pex19b-1 mutant. Despite the reduction in PEX19 levels in pex19b-1, both pex19a-1 and pex19b-1 single mutants lacked notable peroxisomal β-oxidation defects and displayed normal levels and localization of peroxisomal matrix and membrane proteins. The pex19a-1 pex19b-1 double mutant was embryo lethal, indicating a redundantly encoded critical role for PEX19 during embryogenesis. Expressing YFP-tagged versions of either PEX19 isoform rescued this lethality, confirming that PEX19A and PEX19B act redundantly in Arabidopsis. We observed that pex19b-1 enhanced peroxisome-related defects of a subset of peroxin-defective mutants, supporting a role for PEX19 in peroxisome function. Together, our data indicate that Arabidopsis PEX19 promotes peroxisome function and is essential for viability.

  17. Regulation of Signal Transduction by Glutathione Transferases

    Directory of Open Access Journals (Sweden)

    Julie Pajaud

    2012-01-01

    Full Text Available Glutathione transferases (GST are essentially known as enzymes that catalyse the conjugation of glutathione to various electrophilic compounds such as chemical carcinogens, environmental pollutants, and antitumor agents. However, this protein family is also involved in the metabolism of endogenous compounds which play critical roles in the regulation of signaling pathways. For example, the lipid peroxidation product 4-hydroxynonenal (4-HNE and the prostaglandin 15-deoxy-,14-prostaglandin J2 (15d-PGJ2 are metabolized by GSTs and these compounds are known to influence the activity of transcription factors and protein kinases involved in stress response, proliferation, differentiation, or apoptosis. Furthermore, several studies have demonstrated that GSTs are able to interact with different protein partners such as mitogen activated protein kinases (i.e., c-jun N-terminal kinase (JNK and apoptosis signal-regulating kinase 1 (ASK1 which are also involved in cell signaling. New functions of GSTs, including S-glutathionylation of proteins by GSTs and ability to be a nitric oxide (NO carrier have also been described. Taken together, these observations strongly suggest that GST might play a crucial role during normal or cancer cells proliferation or apoptosis.

  18. The Genetic Architecture of Murine Glutathione Transferases.

    Directory of Open Access Journals (Sweden)

    Lu Lu

    Full Text Available Glutathione S-transferase (GST genes play a protective role against oxidative stress and may influence disease risk and drug pharmacokinetics. In this study, massive multiscalar trait profiling across a large population of mice derived from a cross between C57BL/6J (B6 and DBA2/J (D2--the BXD family--was combined with linkage and bioinformatic analyses to characterize mechanisms controlling GST expression and to identify downstream consequences of this variation. Similar to humans, mice show a wide range in expression of GST family members. Variation in the expression of Gsta4, Gstt2, Gstz1, Gsto1, and Mgst3 is modulated by local expression QTLs (eQTLs in several tissues. Higher expression of Gsto1 in brain and liver of BXD strains is strongly associated (P < 0.01 with inheritance of the B6 parental allele whereas higher expression of Gsta4 and Mgst3 in brain and liver, and Gstt2 and Gstz1 in brain is strongly associated with inheritance of the D2 parental allele. Allele-specific assays confirmed that expression of Gsto1, Gsta4, and Mgst3 are modulated by sequence variants within or near each gene locus. We exploited this endogenous variation to identify coexpression networks and downstream targets in mouse and human. Through a combined systems genetics approach, we provide new insight into the biological role of naturally occurring variants in GST genes.

  19. Regulation of signal transduction by glutathione transferases.

    Science.gov (United States)

    Pajaud, Julie; Kumar, Sandeep; Rauch, Claudine; Morel, Fabrice; Aninat, Caroline

    2012-01-01

    Glutathione transferases (GST) are essentially known as enzymes that catalyse the conjugation of glutathione to various electrophilic compounds such as chemical carcinogens, environmental pollutants, and antitumor agents. However, this protein family is also involved in the metabolism of endogenous compounds which play critical roles in the regulation of signaling pathways. For example, the lipid peroxidation product 4-hydroxynonenal (4-HNE) and the prostaglandin 15-deoxy-Δ12,14-prostaglandin J(2) (15d-PGJ(2)) are metabolized by GSTs and these compounds are known to influence the activity of transcription factors and protein kinases involved in stress response, proliferation, differentiation, or apoptosis. Furthermore, several studies have demonstrated that GSTs are able to interact with different protein partners such as mitogen activated protein kinases (i.e., c-jun N-terminal kinase (JNK) and apoptosis signal-regulating kinase 1 (ASK1)) which are also involved in cell signaling. New functions of GSTs, including S-glutathionylation of proteins by GSTs and ability to be a nitric oxide (NO) carrier have also been described. Taken together, these observations strongly suggest that GST might play a crucial role during normal or cancer cells proliferation or apoptosis.

  20. The Genetic Architecture of Murine Glutathione Transferases.

    Science.gov (United States)

    Lu, Lu; Pandey, Ashutosh K; Houseal, M Trevor; Mulligan, Megan K

    2016-01-01

    Glutathione S-transferase (GST) genes play a protective role against oxidative stress and may influence disease risk and drug pharmacokinetics. In this study, massive multiscalar trait profiling across a large population of mice derived from a cross between C57BL/6J (B6) and DBA2/J (D2)--the BXD family--was combined with linkage and bioinformatic analyses to characterize mechanisms controlling GST expression and to identify downstream consequences of this variation. Similar to humans, mice show a wide range in expression of GST family members. Variation in the expression of Gsta4, Gstt2, Gstz1, Gsto1, and Mgst3 is modulated by local expression QTLs (eQTLs) in several tissues. Higher expression of Gsto1 in brain and liver of BXD strains is strongly associated (P < 0.01) with inheritance of the B6 parental allele whereas higher expression of Gsta4 and Mgst3 in brain and liver, and Gstt2 and Gstz1 in brain is strongly associated with inheritance of the D2 parental allele. Allele-specific assays confirmed that expression of Gsto1, Gsta4, and Mgst3 are modulated by sequence variants within or near each gene locus. We exploited this endogenous variation to identify coexpression networks and downstream targets in mouse and human. Through a combined systems genetics approach, we provide new insight into the biological role of naturally occurring variants in GST genes.

  1. Interactions of glutathione transferases with 4-hydroxynonenal.

    Science.gov (United States)

    Balogh, Larissa M; Atkins, William M

    2011-05-01

    Electrophilic products of lipid peroxidation are important contributors to the progression of several pathological states. The prototypical α,β-unsaturated aldehyde, 4-hydroxynonenal (HNE), triggers cellular events associated with oxidative stress, which can be curtailed by the glutathione-dependent elimination of HNE. The glutathione transferases (GSTs) are a major determinate of the intracellular concentration of HNE and can influence susceptibility to toxic effects, particularly when HNE and GST levels are altered in disease states. In this article, we provide a brief summary of the cellular effects of HNE, followed by a review of its GST-catalyzed detoxification, with an emphasis on the structural attributes that play an important role in the interactions with alpha-class GSTs. Some of the key determining characteristics that impart high alkenal activity reside in the unique C-terminal interactions of the GSTA4-4 enzyme. Studies encompassing both kinetic and structural analyses of related isoforms will be highlighted, with additional attention to stereochemical aspects that demonstrate the capacity of GSTA4-4 to detoxify both enantiomers of the biologically relevant racemic mixture while generating a select set of diastereomeric products with subsequent implications. A summary of the literature that examines the interplay between GSTs and HNE in model systems relevant to oxidative stress will also be discussed to demonstrate the magnitude of importance of GSTs in the overall detoxification scheme.

  2. Glutathione transferase mimics : Micellar catalysis of an enzymic reaction

    NARCIS (Netherlands)

    Lindkvist, Björn; Weinander, Rolf; Engman, Lars; Koetse, Marc; Engberts, Jan B.F.N.; Morgenstern, Ralf

    1997-01-01

    Substances that mimic the enzyme action of glutathione transferases (which serve in detoxification) are described. These micellar catalysts enhance the reaction rate between thiols and activated halogenated nitroarenes as well as alpha,beta-unsaturated carbonyls. The nucleophilic aromatic substituti

  3. Thermodynamic, dynamic and solvational properties of PDEδ binding to farnesylated cystein: a model study for uncovering the molecular mechanism of PDEδ interaction with prenylated proteins.

    Science.gov (United States)

    Suladze, S; Ismail, S; Winter, R

    2014-01-30

    The protein PDEδ is an important solubilizing factor for several prenylated proteins including the Ras subfamily members. The binding occurs mainly through the farnesyl anchor of Ras proteins, which is recognized by a hydrophobic pocket of PDEδ. In this study, we carried out a detailed study of the thermodynamic and solvational properties of PDEδ binding to farnesyl-cystein, which serves as a model for PDEδ association to prenylated proteins. Using various biophysical approaches in conjunction with theoretical considerations, we show here that binding of the largely hydrophobic ligand surprisingly has enthalpy-driven signature, and the entropy change is largely controlled by the fine balance between the hydrational and conformational terms. Moreover, binding of PDEδ to farnesyl-cystein is accompanied by an increase in thermal stability, the release of about 150 water molecules from the interacting species, a decrease in solvent accessible surface area, and a marked decrease of the volume fluctuations and hence dynamics of the protein. Altogether, our results shed more light on the molecular mechanism of PDEδ interaction with prenylated Ras proteins, which is also prerequisite for an optimization of the structure-based molecular design of drugs against Ras related diseases and for understanding the multitude of biological functions of PDEδ.

  4. Glutathione transferases in the bioactivation of azathioprine.

    Science.gov (United States)

    Modén, Olof; Mannervik, Bengt

    2014-01-01

    The prodrug azathioprine is primarily used for maintaining remission in inflammatory bowel disease, but approximately 30% of the patients suffer adverse side effects. The prodrug is activated by glutathione conjugation and release of 6-mercaptopurine, a reaction most efficiently catalyzed by glutathione transferase (GST) A2-2. Among five genotypes of GST A2-2, the variant A2*E has threefold-fourfold higher catalytic efficiency with azathioprine, suggesting that the expression of A2*E could boost 6-mercaptopurine release and adverse side effects in treated patients. Structure-activity studies of the GST A2-2 variants and homologous alpha class GSTs were made to delineate the determinants of high catalytic efficiency compared to other alpha class GSTs. Engineered chimeras identified GST peptide segments of importance, and replacing the corresponding regions in low-activity GSTs by these short segments produced chimeras with higher azathioprine activity. By contrast, H-site mutagenesis led to decreased azathioprine activity when active-site positions 208 and 213 in these favored segments were mutagenized. Alternative substitutions indicated that hydrophobic residues were favored. A pertinent question is whether variant A2*E represents the highest azathioprine activity achievable within the GST structural framework. This issue was addressed by mutagenesis of H-site residues assumed to interact with the substrate based on molecular modeling. The mutants with notably enhanced activities had small or polar residues in the mutated positions. The most active mutant L107G/L108D/F222H displayed a 70-fold enhanced catalytic efficiency with azathioprine. The determination of its structure by X-ray crystallography showed an expanded H-site, suggesting improved accommodation of the transition state for catalysis.

  5. EVALUATION OF SERUM CHOLESTEROL, AMINO TRANSFERASES

    Directory of Open Access Journals (Sweden)

    Anantha Babu

    2016-01-01

    Full Text Available BACKGROUND AND AIMS The purpose of this study was to determine the efficacy of red yeast rice (Monascus purpureus-fermented rice in lowering cholesterol in the blood. At the same time, alanine aminotranferase (ALT, aspartate aminotransferase (AST and gamma-glutamyl transferase (γ-GT were measured for notable side effects in the liver. Possible muscle damage was determined by measuring creatine kinase (CK. METHODS The cholesterol lowering effect in serum of red yeast rice-fed rats were studied over a 42-day feeding period. A total of 16 male Sprague-Dawley rats were randomised into 8 per group: control and treated. Treated rats were administered 1.35g/kg/day. Control rats were maintained on ordinary rat chow. RESULTS Serum cholesterol levels were significantly decreased by 19.13% in treated group compared to controls. This treatment also showed increase in serum ALT and AST activities by 41.90% and 21.53%, respectively. Mean CK activity in treated rats showed an increase by 32.32% when compared with control rats. γ-GT is the only enzyme that showed a decrease of 15.16% in sera of treated rats. Body weights of control and treated rats increased significantly by 10% end of feeding period but were not due to treatment. CONCLUSION Red yeast rice significantly decreased serum cholesterol level at a dosage of 1.35g/kg/day. However, the differences in serum enzyme activities between control and treated rats were not significant.

  6. Binding of nitrogen-containing bisphosphonates (N-BPs) to the Trypanosoma cruzi farnesyl diphosphate synthase homodimer

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Chuan-Hsiang; Gabelli, Sandra B.; Oldfield, Eric; Amzel, L. Mario (UIUC); (JHU-MED)

    2010-11-15

    Bisphosphonates (BPs) are a class of compounds that have been used extensively in the treatment of osteoporosis and malignancy-related hypercalcemia. Some of these compounds act through inhibition of farnesyl diphosphate synthase (FPPS), a key enzyme in the synthesis of isoprenoids. Recently, nitrogen-containing bisphosphonates (N-BPs) used in bone resorption therapy have been shown to be active against Trypanosoma cruzi, the parasite that causes American trypanosomiasis (Chagas disease), suggesting that they may be used as anti-trypanosomal agents. The crystal structures of TcFPPS in complex with substrate (isopentenyl diphosphate, IPP) and five N-BP inhibitors show that the C-1 hydroxyl and the nitrogen-containing groups of the inhibitors alter the binding of IPP and the conformation of two TcFPPS residues, Tyr94 and Gln167. Isothermal titration calorimetry experiments suggest that binding of the first N-BPs to the homodimeric TcFPPS changes the binding properties of the second site. This mechanism of binding of N-BPs to TcFPPS is different to that reported for the binding of the same compounds to human FPPS.

  7. Enhanced triterpene accumulation in Panax ginseng hairy roots overexpressing mevalonate-5-pyrophosphate decarboxylase and farnesyl pyrophosphate synthase.

    Science.gov (United States)

    Kim, Yong-Kyoung; Kim, Yeon Bok; Uddin, Md Romij; Lee, Sanghyun; Kim, Soo-Un; Park, Sang Un

    2014-10-17

    To elucidate the function of mevalonate-5-pyrophosphate decarboxylase (MVD) and farnesyl pyrophosphate synthase (FPS) in triterpene biosynthesis, the genes governing the expression of these enzymes were transformed into Panax ginseng hairy roots. All the transgenic lines showed higher expression levels of PgMVD and PgFPS than that by the wild-type control. Among the hairy root lines transformed with PgMVD, M18 showed the highest level of transcription compared to the control (14.5-fold higher). Transcriptions of F11 and F20 transformed with PgFPS showed 11.1-fold higher level compared with control. In triterpene analysis, M25 of PgMVD produced 4.4-fold higher stigmasterol content (138.95 μg/100 mg, dry weight [DW]) than that by the control; F17 of PgFPS showed the highest total ginsenoside (36.42 mg/g DW) content, which was 2.4-fold higher compared with control. Our results indicate that metabolic engineering in P. ginseng was successfully achieved through Agrobacterium rhizogenes-mediated transformation and that the accumulation of phytosterols and ginsenosides was enhanced by introducing the PgMVD and PgFPS genes into the hairy roots of the plant. Our results suggest that PgMVD and PgFPS play an important role in the triterpene biosynthesis of P. ginseng.

  8. Biosynthesis of anthecotuloide, an irregular sesquiterpene lactone from Anthemis cotula L. (Asteraceae) via a non-farnesyl diphosphate route.

    Science.gov (United States)

    van Klink, John; Becker, Hans; Andersson, Susannah; Boland, Wilhelm

    2003-05-07

    Retrobiosynthetic analysis of the allergenic sesquiterpene lactone, anthecotuloide, suggested that this natural product could be formed either by head to head condensation of geranyl diphosphate with dimethylallyl diphosphate, or from farnesyl diphosphate (FPP), the accepted regular sesquiterpene precursor via the rearrangement of a germacranolide precursor. Isotopic labelling of anthecotuloide has now been achieved by feeding [1-(13)C]-glucose, [U-13C6]-glucose and [6,6-(2)H2]-glucose to aseptically grown plantlets of Anthemis cotula(family Asteraceae). Analysis of labelling patterns and absolute 13C abundances using quantitative 13C NMR spectroscopy showed that the isoprene building blocks of this sesquiterpene are formed exclusively via the MEP terpene biosynthetic pathway. This was supported by results from an experiment using [U-13C6]-glucose. A deuterium labelling experiment using [6,6-(2)H2]-glucose supported the original proposal and showed that anthecotuloide is formed from a non FPP precursor. Isotope ratio mass spectrometry suggested that there were two pathways for sesquiterpene biosynthesis in A. cotula.

  9. Sesquiterpene synthases Cop4 and Cop6 from Coprinus cinereus: Catalytic promiscuity and cyclization of farnesyl pyrophosphate geometrical isomers

    Science.gov (United States)

    Lopez-Gallego, Fernando; Agger, Sean A.; Pella, Daniel A.; Distefano, Mark D.; Schmidt-Dannert, Claudia

    2010-01-01

    Sesquiterpene synthases catalyze with different catalytic fidelity the cyclization of farnesyl pyrophosphate (FPP) into hundreds of known compounds with diverse structures and stereochemistries. Two sesquiterpene synthases, Cop4 and Cop6, were previously isolated from Coprinus cinereus as part of a fungal genome survey. This study investigates the reaction mechanism and catalytic fidelity of the two enzymes. Cyclization of all-trans-FPP ((E,E)-FPP) was compared to the cyclization of the cis-trans isomer of FPP ((Z,E)-FPP) as a surrogate for the secondary cisoid neryl cation intermediate generated by sesquiterpene synthases capable of isomerizing the C2-C3 π bond of all-trans-FPP. Cop6 is a “high-fidelity” α-cuprenene synthase that retains its fidelity under various conditions tested. Cop4 is a catalytically promiscuous enzyme that cyclizes (E,E)-FPP into multiple products, including (−)-germacrene D and cubebol. Changing the pH of the reaction drastically alters the fidelity of Cop4 and makes it a highly selective enzyme. Cyclization of (Z,E)-FPP by Cop4 and Cop6 yields products that are very different from those obtained with (E,E)-FPP. Conversion of (E,E)-FPP proceeds via a (6R)-β-bisabolyl carbocation in the case of Cop6 and an (E,E)-germacradienyl carbocation in the case of Cop4. However, (Z,E)-FPP is cyclized via a (6S)-β-bisabolene carbocation by both enzymes. Structural modeling suggests that differences in the active site and the loop that covers the active site of the two enzymes may explain their different catalytic fidelities. PMID:20419721

  10. Rational design of an organometallic glutathione transferase inhibitor

    Energy Technology Data Exchange (ETDEWEB)

    Ang, W.H.; Parker, L.J.; De Luca, A.; Juillerat-Jeanneret, L.; Morton, C.J.; LoBello, M.; Parker, M.W.; Dyson, P.J.; (ISIC)

    2010-08-17

    A hybrid organic-inorganic (organometallic) inhibitor was designed to target glutathione transferases. The metal center is used to direct protein binding, while the organic moiety acts as the active-site inhibitor. The mechanism of inhibition was studied using a range of biophysical and biochemical methods.

  11. Interaction of pleuromutilin derivatives with the ribosomal peptidyl transferase center

    DEFF Research Database (Denmark)

    Long, K. S.; Hansen, L. K.; Jakobsen, L.;

    2006-01-01

    Tiamulin is a pleuromutilin antibiotic that is used in veterinary medicine. The recently published crystal structure of a tiamulin-50S ribosomal subunit complex provides detailed information about how this drug targets the peptidyl transferase center of the ribosome. To promote rational design...

  12. Homogentisate solanesyl transferase (HST) cDNA’s in maize

    Science.gov (United States)

    Maize white seedling 3 (w3) has served as a model albino-seedling mutant since its discovery in 1923. We show that the w3 phenotype is caused by disruptions in homogentisate solanesyl transferase (HST), an enzyme that catalyzes the committed step in plastoquinone-9 (PQ9) biosynthesis. This reaction ...

  13. Association of farnesyl diphosphate synthase polymorphisms and response to alendronate treatment in Chinese postmenopausal women with osteoporosis

    Institute of Scientific and Technical Information of China (English)

    Liu Yi; Liu Haijuan; Li Mei; Zhou Peiran; Xing Xiaoping; Xia Weibo; Zhang Zhenlin

    2014-01-01

    Background Genetic factors are important in the pathogenesis of osteoporosis,but less is known about the genetic determinants of osteoporosis treatment.We aimed to explore the association between the gene polymorphisms of key enzyme farnesyl diphosphate synthase (FDPS) in mevalonate signaling pathway of osteoclast and response to alendronate therapy in osteoporotic postmenopausal women in China.Methods The study group comprised 639 postmenopausal women aged (62.2±7.0) years with osteoporosis or osteopenia who had been randomly assigned to low dose group (70 mg/2w) or standard dose group (70 mg/w) of alendronate in this 1-year study.We identified allelic variant of the FDPS gene using the polymerase chain reaction and restriction enzyme Faul.Before and after treatment,serum levels of calcium,phosphate,alkaline phosphatase (ALP),cross linked C-telopeptide of type Ⅰ collagen (β-CTX) were detected.Bone mineral density (BMD) at lumbar spine and proximal femur was measured.The association was analyzed between the polymorphisms of FDPS gene and the changes of BMD,bone turnover biomarkers after the treatment.Results The FDPS rs2297480 polymorphisms were associated with baseline BMD at femoral neck,and patients with CC genotype had significantly higher baseline femoral neck BMD ((733.6±84.1) mg/cm2) than those with AC genotypes ((703.0±86.9) mg/cm2) and AA genotypes ((649.8±62.4) mg/cm2) (P <0.01).No significant difference in BMD at lumbar spine was observed among different genotypes of FDPS.The percentage change of serum ALP level was significantly lower in patients with CC genotype (-22.9%) than that in those with AC genotype (-24.1%) and AA genotype (-29.8%) of FDPS after 12 months of alendronate treatment (P <0.05).Neither percentage change of BMD nor β-CTX level after alendronate treatment had association with FDPS genotype.Conclusions FDPS gene was probably a candidate gene to predict femoral neck BMD at baseline.FDPS gene alleles could predict

  14. Oral Medication

    Science.gov (United States)

    ... Size: A A A Listen En Español Oral Medication The first treatment for type 2 diabetes blood ... new — even over-the-counter items. Explore: Oral Medication How Much Do Oral Medications Cost? Save money ...

  15. Oral myiasis

    OpenAIRE

    Thalaimalai Saravanan; Mathan A Mohan; Meera Thinakaran; Saneem Ahammed

    2015-01-01

    Myiasis is a pathologic condition in humans occurring because of parasitic infestation. Parasites causing myiasis belong to the order Diptera. Oral myiasis is seen secondary to oral wounds, suppurative lesions, and extraction wounds, especially in individuals with neurological deficit. In such cases, neglected oral hygiene and halitosis attracts the flies to lay eggs in oral wounds resulting in oral myiasis. We present a case of oral myiasis in 40-year-old male patient with mental disability ...

  16. ANALISIS ENZIM ALANIN AMINO TRANSFERASE (ALAT, ASPARTAT AMINO TRANSFERASE (ASAT, UREA DARAH, DAN HISTOPATOLOGIS HATI DAN GINJAL TIKUS PUTIH GALUR Sprague-Dawley SETELAH PEMBERIAN ANGKAK [The Effects of Angkak Administration in Sprague-Dawley White Rats on Alanine Amino Transferase (ALAT and Aspartic Amino Transferase (ASAT Enzyme, Blood Urea, and Liver and Kidney Histopathology Test

    Directory of Open Access Journals (Sweden)

    HASIM DANURI

    2009-06-01

    Full Text Available Acute toxicity of angkak had been tested on 2 months aged male Sprague-Dawley white rats. Twenty five rats were divided into 5 groups; control, 2.5 g/kg body weight (bw, 5 g/kg bw, 10 g/kg bw and 15 g/kg bw, and each group was administered by angkak in water orally. The toxic effect of angkak to liver and kidney were tested by biochemical analysis for the activity of enzyme alanin amino transferase (ALAT/ EC 2.6.1.2, enzyme aspartate amino transferase (ASAT/ EC 2.6.1.1 and the level of urea in blood at one day before (H-1 and after (H+1 the treatment, as well as 6 days after the treatment (H+6. The mortality rate and clinical symptoms were observed after 24 hours until 6 days after treatment. The rats were necropsied to observe the lesion of liver and kidney both macroscopically and microscopically.The result shows that all rats still survived since 24 hours to 6 days after the test. During the treatment with ad libitum rat chow contained 18% protein, the body weight of the rats were unsignificantly increased (P>0.05. There were no changed of the appetite, eyes condition, fur, and behaviour of the rats. However, the feces of the rats which were treated with angkak are reddish. The activity of ALAT, ASAT enzyme as well as the urea level in blood were significantly increased as shown on H+1 compared to H-1 within all treatment groups, after that there were no significant changes in those parameter on H+6 compared to H+1. The histopathological result due to angkak on kidney shows less lesions and these lesions were reversible.

  17. Proton mobilities in crambin and glutathione S-transferase

    Science.gov (United States)

    Wanderlingh, U. N.; Corsaro, C.; Hayward, R. L.; Bée, M.; Middendorf, H. D.

    2003-08-01

    Using a neutron backscattering spectrometer, the temperature dependence of mean-square atomic displacements derived from window-integrated quasielastic spectra was measured for two D 2O-hydrated proteins: crambin and glutathione S-transferase. Analyses show that the anharmonic dynamics observed around and above 200 K is consistent with a description in terms of proton/deuteron jumps within asymmetric double-minimum potentials. Also determined were activation energies along with estimates of effective masses and average oscillator energies.

  18. Interaction of pleuromutilin derivatives with the ribosomal peptidyl transferase center

    DEFF Research Database (Denmark)

    Long, K. S.; Hansen, L. K.; Jakobsen, L.

    2006-01-01

    are similarly anchored in the binding pocket by the common tricyclic mutilin core. However, varying effects are observed at U2584 and U2585, indicating that the side chain extensions adopt distinct conformations within the cavity and thereby affect the rRNA conformation differently. An Escherichia coli L3...... site. The data suggest that pleuromutilin drugs with enhanced antimicrobial activity may be obtained by maximizing the number of interactions between the side chain moiety and the peptidyl transferase cavity....

  19. [Glutathione S-transferase of alpha class from pike liver].

    Science.gov (United States)

    Borvinskaia, E V; Smirnov, L P; Nemova, N N

    2013-01-01

    In this study, glutathione S-transferase (GST) was isolated from the liver of pike Esox lucius, which was homogenous according to SDS-PAGE and isoelectrofocusing. It is a homodimer with subunits mass 25235.36 Da (according to HPLC-MS/MS) and pI about 6.4. Substrate specificity, thermostability, some kinetic characteristics and optimum pH were determined. The enzyme was identified as Alpha class GST.

  20. Synthesis, chiral high performance liquid chromatographic resolution and enantiospecific activity of a potent new geranylgeranyl transferase inhibitor, 2-hydroxy-3-imidazo[1,2-a]pyridin-3-yl-2-phosphonopropionic acid.

    Science.gov (United States)

    McKenna, Charles E; Kashemirov, Boris A; Błazewska, Katarzyna M; Mallard-Favier, Isabelle; Stewart, Charlotte A; Rojas, Javier; Lundy, Mark W; Ebetino, Frank H; Baron, Rudi A; Dunford, James E; Kirsten, Marie L; Seabra, Miguel C; Bala, Joy L; Marma, Mong S; Rogers, Michael J; Coxon, Fraser P

    2010-05-13

    3-(3-Pyridyl)-2-hydroxy-2-phosphonopropanoic acid (3-PEHPC, 1) is a phosphonocarboxylate (PC) analogue of 2-(3-pyridyl)-1-hydroxyethylidenebis(phosphonic acid) (risedronic acid, 2), an osteoporosis drug that decreases bone resorption by inhibiting farnesyl pyrophosphate synthase (FPPS) in osteoclasts, preventing protein prenylation. 1 has lower bone affinity than 2 and weakly inhibits Rab geranylgeranyl transferase (RGGT), selectively preventing prenylation of Rab GTPases. We report here the synthesis and biological studies of 2-hydroxy-3-imidazo[1,2-a]pyridin-3-yl-2-phosphonopropionic acid (3-IPEHPC, 3), the PC analogue of minodronic acid 4. Like 1, 3 selectively inhibited Rab11 vs. Rap 1A prenylation in J774 cells, and decreased cell viability, but was 33-60x more active in these assays. After resolving 3 by chiral HPLC (>98% ee), we found that (+)-3-E1 was much more potent than (-)-3-E2 in an isolated RGGT inhibition assay, approximately 17x more potent (LED 3 microM) than (-)-3-E2 in inhibiting Rab prenylation in J774 cells and >26x more active in the cell viability assay. The enantiomers of 1 exhibited a 4-fold or smaller potency difference in the RGGT and prenylation inhibition assays.

  1. Determination of Activity of the Enzymes Hypoxanthine Phosphoribosyl Transferase (HPRT) and Adenine Phosphoribosyl Transferase (APRT) in Blood Spots on Filter Paper.

    Science.gov (United States)

    Auler, Kasie; Broock, Robyn; Nyhan, William L

    2015-07-01

    Hypoxanthine-guanine phosphoribosyl-transferase (HPRT) deficiency is the cause of Lesch-Nyhan disease. Adenine phosphoribosyl-transferase (APRT) deficiency causes renal calculi. The activity of each enzyme is readily determined on spots of whole blood on filter paper. This unit describes a method for detecting deficiencies of HPRT and APRT. Copyright © 2015 John Wiley & Sons, Inc.

  2. Suppressing Farnesyl Diphosphate Synthase Alters Chloroplast Development and Triggers Sterol-Dependent Induction of Jasmonate- and Fe-Related Responses1[OPEN

    Science.gov (United States)

    Andrade, Paola; Caudepón, Daniel; Arró, Montserrat

    2016-01-01

    Farnesyl diphosphate synthase (FPS) catalyzes the synthesis of farnesyl diphosphate from isopentenyl diphosphate and dimethylallyl diphosphate. Arabidopsis (Arabidopsis thaliana) contains two genes (FPS1 and FPS2) encoding FPS. Single fps1 and fps2 knockout mutants are phenotypically indistinguishable from wild-type plants, while fps1/fps2 double mutants are embryo lethal. To assess the effect of FPS down-regulation at postembryonic developmental stages, we generated Arabidopsis conditional knockdown mutants expressing artificial microRNAs devised to simultaneously silence both FPS genes. Induction of silencing from germination rapidly caused chlorosis and a strong developmental phenotype that led to seedling lethality. However, silencing of FPS after seed germination resulted in a slight developmental delay only, although leaves and cotyledons continued to show chlorosis and altered chloroplasts. Metabolomic analyses also revealed drastic changes in the profile of sterols, ubiquinones, and plastidial isoprenoids. RNA sequencing and reverse transcription-quantitative polymerase chain reaction transcriptomic analysis showed that a reduction in FPS activity levels triggers the misregulation of genes involved in biotic and abiotic stress responses, the most prominent one being the rapid induction of a set of genes related to the jasmonic acid pathway. Down-regulation of FPS also triggered an iron-deficiency transcriptional response that is consistent with the iron-deficient phenotype observed in FPS-silenced plants. The specific inhibition of the sterol biosynthesis pathway by chemical and genetic blockage mimicked these transcriptional responses, indicating that sterol depletion is the primary cause of the observed alterations. Our results highlight the importance of sterol homeostasis for normal chloroplast development and function and reveal important clues about how isoprenoid and sterol metabolism is integrated within plant physiology and development. PMID

  3. Enzymatic synthesis of farnesyl laurate in organic solvent: initial water activity, kinetics mechanism, optimization of continuous operation using packed bed reactor and mass transfer studies.

    Science.gov (United States)

    Rahman, N K; Kamaruddin, A H; Uzir, M H

    2011-08-01

    The influence of water activity and water content was investigated with farnesyl laurate synthesis catalyzed by Lipozyme RM IM. Lipozyme RM IM activity depended strongly on initial water activity value. The best results were achieved for a reaction medium with an initial water activity of 0.11 since it gives the best conversion value of 96.80%. The rate constants obtained in the kinetics study using Ping-Pong-Bi-Bi and Ordered-Bi-Bi mechanisms with dead-end complex inhibition of lauric acid were compared. The corresponding parameters were found to obey the Ordered-Bi-Bi mechanism with dead-end complex inhibition of lauric acid. Kinetic parameters were calculated based on this model as follows: V (max) = 5.80 mmol l(-1) min(-1) g enzyme(-1), K (m,A) = 0.70 mmol l(-1) g enzyme(-1), K (m,B) = 115.48 mmol l(-1) g enzyme(-1), K (i) = 11.25 mmol l(-1) g enzyme(-1). The optimum conditions for the esterification of farnesol with lauric acid in a continuous packed bed reactor were found as the following: 18.18 cm packed bed height and 0.9 ml/min substrate flow rate. The optimum molar conversion of lauric acid to farnesyl laurate was 98.07 ± 0.82%. The effect of mass transfer in the packed bed reactor has also been studied using two models for cases of reaction limited and mass transfer limited. A very good agreement between the mass transfer limited model and the experimental data obtained indicating that the esterification in a packed bed reactor was mass transfer limited.

  4. Oral myiasis

    Directory of Open Access Journals (Sweden)

    Thalaimalai Saravanan

    2015-01-01

    Full Text Available Myiasis is a pathologic condition in humans occurring because of parasitic infestation. Parasites causing myiasis belong to the order Diptera. Oral myiasis is seen secondary to oral wounds, suppurative lesions, and extraction wounds, especially in individuals with neurological deficit. In such cases, neglected oral hygiene and halitosis attracts the flies to lay eggs in oral wounds resulting in oral myiasis. We present a case of oral myiasis in 40-year-old male patient with mental disability and history of epilepsy.

  5. Human cytosolic glutathione transferases: structure, function, and drug discovery.

    Science.gov (United States)

    Wu, Baojian; Dong, Dong

    2012-12-01

    Glutathione transferases (GSTs) are important detoxifying enzymes that catalyze the conjugation of electrophilic substrates to glutathione. In recent years, GSTs have been of great interest in pharmacology and drug development because of their involvement in many important biological processes such as steroid and prostaglandin biosynthesis, tyrosine catabolism, and cell apoptosis. This review describes crystal structures for cytosolic GSTs and correlates active-site features with enzyme functions (e.g., steroid synthesis, tyrosine degradation, and dehydroascorbate reduction) and substrate selectivity. Use of these crystal structures for the design of specific inhibitors for several GST enzymes is also discussed.

  6. Oral Thrush

    Science.gov (United States)

    ... feeding mothers In addition to the distinctive white mouth lesions, infants may have trouble feeding or be fussy ... candidiasis (yeast infection) patient information. American Academy of Oral & Maxillofacial Pathology. http://www.aaomp.org/public/oral-candidiasis.php. ...

  7. Molecular basis for the presence of glycosylated onco-foetal fibronectin in oral carcinomas

    DEFF Research Database (Denmark)

    Wandall, Hans H; Dabelsteen, Sally; Sørensen, Jens Ahm;

    2007-01-01

    Glycosylated onco-foetal fibronectin (GOF) deposited in the stroma of oral squamous cell carcinomas correlates with survival. One of the two polypeptide GalNAc-transferases, GalNAc-T3 or GalNAc-T6, is required for the biosynthesis of GOF by the initiation of a unique O-glycan in the alternative...... spliced IIICS region. Using cell culture experiments, immunohistochemical staining of primary tissue, and RT-PCR of tumour cells isolated by laser capture techniques we have examined the molecular basis for the production of GOF in oral carcinomas. Immuno-histochemical investigation confirmed the stromal...... deposition of GOF in oral carcinomas. However, neither GalNAc-T3 nor GalNAc-T6 could be detected in stromal fibroblasts. In contrast both transferases were present in the oral squamous carcinoma cells, suggesting that GOF is produced by the oral cancer cells and not only the stromal cells. RT-PCR analysis...

  8. Oral Dysfunction

    OpenAIRE

    鈴木, 規子; スズキ, ノリコ; Noriko, SUZUKI

    2004-01-01

    The major oral functions can be categorized as mastication, swallowing, speech and respiratory functions. Dysfunction of these results in dysphagia, speech disorders and abnormal respiration (such as Sleep Apnea). These functions relate to dentistry in the occurrence of : (1) oral preparatory and oral phases, (2) articulation disorders and velopharyngeal incompetence (VPI), and (3) mouth breathing, respiratory and blowing disorders. These disorders are related to oral and maxillofacial diseas...

  9. 21 CFR 862.1315 - Galactose-1-phosphate uridyl transferase test system.

    Science.gov (United States)

    2010-04-01

    ... of the enzyme galactose-1-phosphate uridyl transferase in erythrocytes (red blood cells... hereditary disease galactosemia (disorder of galactose metabolism) in infants. (b) Classification. Class II....

  10. Electrochemical evaluation of glutathione S-transferase kinetic parameters.

    Science.gov (United States)

    Enache, Teodor Adrian; Oliveira-Brett, Ana Maria

    2015-02-01

    Glutathione S-transferases (GSTs), are a family of enzymes belonging to the phase II metabolism that catalyse the formation of thioether conjugates between the endogenous tripeptide glutathione and xenobiotic compounds. The voltammetric behaviour of glutathione (GSH), 1-chloro-2,4-dinitrobenzene (CDNB) and glutathione S-transferase (GST), as well as the catalytic conjugation reaction of GSH to CDNB by GST was investigated at room temperature, T=298.15K (25°C), at pH6.5, for low concentration of substrates and enzyme, using differential pulse (DP) voltammetry at a glassy carbon electrode. Only GSH can be oxidized; a sensitivity of 0.14nA/μM and a LOD of 6.4μM were obtained. The GST kinetic parameter electrochemical evaluation, in relation to its substrates, GSH and CDNB, using reciprocal Michaelis-Menten and Lineweaver-Burk double reciprocal plots, was determined. A value of KM~100μM was obtained for either GSH or CDNB, and Vmax varied between 40 and 60μmol/min per mg of GST.

  11. A novel method for screening the glutathione transferase inhibitors

    Directory of Open Access Journals (Sweden)

    Węgrzyn Grzegorz

    2009-03-01

    Full Text Available Abstract Background Glutathione transferases (GSTs belong to the family of Phase II detoxification enzymes. GSTs catalyze the conjugation of glutathione to different endogenous and exogenous electrophilic compounds. Over-expression of GSTs was demonstrated in a number of different human cancer cells. It has been found that the resistance to many anticancer chemotherapeutics is directly correlated with the over-expression of GSTs. Therefore, it appears to be important to find new GST inhibitors to prevent the resistance of cells to anticancer drugs. In order to search for glutathione transferase (GST inhibitors, a novel method was designed. Results Our results showed that two fragments of GST, named F1 peptide (GYWKIKGLV and F2 peptide (KWRNKKFELGLEFPNL, can significantly inhibit the GST activity. When these two fragments were compared with several known potent GST inhibitors, the order of inhibition efficiency (measured in reactions with 2,4-dinitrochlorobenzene (CDNB and glutathione as substrates was determined as follows: tannic acid > cibacron blue > F2 peptide > hematin > F1 peptide > ethacrynic acid. Moreover, the F1 peptide appeared to be a noncompetitive inhibitor of the GST-catalyzed reaction, while the F2 peptide was determined as a competitive inhibitor of this reaction. Conclusion It appears that the F2 peptide can be used as a new potent specific GST inhibitor. It is proposed that the novel method, described in this report, might be useful for screening the inhibitors of not only GST but also other enzymes.

  12. The omega-class glutathione transferases: structure, function, and genetics.

    Science.gov (United States)

    Board, Philip G

    2011-05-01

    The omega class of glutathione transferases (GSTs) is a relatively ancient member of the cytosolic GST superfamily, and the omega-class GSTs are found in plants, animals, and some microbial species. The omega-class GSTs exhibit the canonical GST fold, but, unlike other GSTs, the omega-class GSTs have a cysteine residue in their active site. Consequently, the omega-class GSTs catalyze a range of thiol transferase and reduction reactions that are not catalyzed by members of the other classes. Human GSTO1-1 can catalyze the reduction of monomethylarsonic acid (V), but this does not appear to be physiologically important in cases of high environmental arsenic exposure. GSTO1-1 also plays an important role in the biotransformation of reactive α-haloketones to nontoxic acetophenones. Genetic variation is common in the omega-class GST genes, and variants that result in deficiency of GSTO1-1 have been characterized. Genetic linkage studies have discovered associations between GSTO genes and the age at onset of Alzheimer's disease, Parkinson's disease, and amyotrophic lateral sclerosis. The mechanism underlying this association with neurological disease may derive from the capacity of omega-class GSTs to mitigate oxidative stress or their role in activating the proinflammatory cytokine, interleukin-1β.

  13. A glutathione s-transferase confers herbicide tolerance in rice

    Directory of Open Access Journals (Sweden)

    Tingzhang Hu

    2014-07-01

    Full Text Available Plant glutathione S-transferases (GSTs have been a focus of attention due to their role in herbicide detoxification. OsGSTL2 is a glutathione S-transferase, lambda class gene from rice (Oryza sativa L.. Transgenic rice plants over-expressing OsGSTL2 were generated from rice calli by the use of an Agrobacterium transformation system, and were screened by a combination of hygromycin resistance, PCR and Southern blot analysis. In the vegetative tissues of transgenic rice plants, the over-expression of OsGSTL2 not only increased levels of OsGSTL2 transcripts, but also GST and GPX expression, while reduced superoxide. Transgenic rice plants also showed higher tolerance to glyphosate and chlorsulfuron, which often contaminate agricultural fields. The findings demonstrate the detoxification role of OsGSTL2 in the growth and development of rice plants. It should be possible to apply the present results to crops for developing herbicide tolerance and for limiting herbicide contamination in the food chain.

  14. Acrolein-detoxifying isozymes of glutathione transferase in plants.

    Science.gov (United States)

    Mano, Jun'ichi; Ishibashi, Asami; Muneuchi, Hitoshi; Morita, Chihiro; Sakai, Hiroki; Biswas, Md Sanaullah; Koeduka, Takao; Kitajima, Sakihito

    2017-02-01

    Acrolein is a lipid-derived highly reactive aldehyde, mediating oxidative signal and damage in plants. We found acrolein-scavenging glutathione transferase activity in plants and purified a low K M isozyme from spinach. Various environmental stressors on plants cause the generation of acrolein, a highly toxic aldehyde produced from lipid peroxides, via the promotion of the formation of reactive oxygen species, which oxidize membrane lipids. In mammals, acrolein is scavenged by glutathione transferase (GST; EC 2.5.1.18) isozymes of Alpha, Pi, and Mu classes, but plants lack these GST classes. We detected the acrolein-scavenging GST activity in four species of plants, and purified an isozyme showing this activity from spinach (Spinacia oleracea L.) leaves. The isozyme (GST-Acr), obtained after an affinity chromatography and two ion exchange chromatography steps, showed the K M value for acrolein 93 μM, the smallest value known for acrolein-detoxifying enzymes in plants. Peptide sequence homology search revealed that GST-Acr belongs to the GST Tau, a plant-specific class. The Arabidopsis thaliana GST Tau19, which has the closest sequence similar to spinach GST-Acr, also showed a high catalytic efficiency for acrolein. These results suggest that GST plays as a scavenger for acrolein in plants.

  15. Characterization of glutathione S-transferase of Taenia solium.

    Science.gov (United States)

    Vibanco-Pérez, N; Jiménez, L; Merchant, M T; Landa, A

    1999-06-01

    A Taenia solium glutathione-S-transferase fraction (SGSTF) was isolated from a metacestode crude extract by affinity chromatography on reduced glutathione (GSH)-sepharose. The purified fraction displayed a specific glutathione S-transferase (GST) activity of 2.8 micromol/min/mg and glutathione peroxidase selenium-independent activity of 0.22 micromol/min/mg. Enzymatic characterization of the fraction suggested that the activity was closer to the mammalian mu-class GSTs. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis, gel filtration, and enzyme activity analysis showed that the fraction was composed of a major band of Mr = 26 kd and that the active enzyme was dimeric. Immunohistochemical studies using specific antibodies against the major 26-kd band of the SGSTF indicated that GST protein was present in the tegument, parenchyma, protonephridial, and tegumentary cytons of the T. solium metacestode. Antibodies generated against the SGSTF tested in western blot showed cross-reactivity against GSTs purified from Taenia saginata, T. taeniaeformis, and T. crassiceps, but did not react with GSTs from Schistosoma mansoni, or mice, rabbit, and pig liver tissue. Furthermore, immunization of mice with SGSTF reduced the metacestode burden up to 74.2%. Our findings argue in favor of GST having an important role in the survival of T. solium in its hosts.

  16. Increased transcription of Glutathione S-transferases in acaricide exposed scabies mites

    Directory of Open Access Journals (Sweden)

    Currie Bart J

    2010-05-01

    Full Text Available Abstract Background Recent evidence suggests that Sarcoptes scabiei var. hominis mites collected from scabies endemic communities in northern Australia show increasing tolerance to 5% permethrin and oral ivermectin. Previous findings have implicated detoxification pathways in developing resistance to these acaricides. We investigated the contribution of Glutathione S-transferase (GST enzymes to permethrin and ivermectin tolerance in scabies mites using biochemical and molecular approaches. Results Increased in vitro survival following permethrin exposure was observed in S. scabiei var. hominis compared to acaricide naïve mites (p in vitro permethrin susceptibility, confirming GST involvement in permethrin detoxification. Assay of GST enzymatic activity in mites demonstrated that S. scabiei var. hominis mites showed a two-fold increase in activity compared to naïve mites (p S. scabiei var. canis- mu 1 (p S. scabiei var. hominis mites collected from a recurrent crusted scabies patient over the course of ivermectin treatment. Conclusions These findings provide further support for the hypothesis that increased drug metabolism and efflux mediate permethrin and ivermectin resistance in scabies mites and highlight the threat of emerging acaricide resistance to the treatment of scabies worldwide. This is one of the first attempts to define specific genes involved in GST mediated acaricide resistance at the transcriptional level, and the first application of such studies to S. scabiei, a historically challenging ectoparasite.

  17. Relationship between Farnesylation of prelamin A and aging%核层蛋白A前体的法尼基化与衰老

    Institute of Scientific and Technical Information of China (English)

    袁源; 陈维春; 刘新光; 周中军

    2011-01-01

    Specific mutation in LMNA gives rise to a truncated prelamin A called progerin leading to Hutchinson-Gilford progeria syndrome (HGPS). A more severe progeroid disorder, restrictive dermopathy (RD), is caused by the loss of the prelamin A-processing enzyme, ZMPSTE24. The absence of ZMPSTE24 prevents the endoproteolytic processing of famesyl-prelamin A to mature lamin A and leads to the accumulation of farnesyl-prelamin A. In both HGPS and RD, the farnesyl-prelamin A is targeted to the nuclear envelope, where it interferes with the integrity of the nuclear envelope and causes misshapen cell nuclei, resulting in cellular senescence. Recent studies have shown that the frequency of misshapen nuclei can be reduced by treating cells with a famesyltransferase inhibitor (FTI). Also, administering an FTI to mouse models of HGPS and RD ameliorates the phenotypes of progeria. This paper summarizes the advance in study on the contribution of prelamin A farnesylation to premature aging.%编码核层蛋白A(lamin A)的LMNA基因突变导致法尼基化的核层蛋白A前体(prelamin A)不能被进一步加工成成熟的核层蛋白A,从而导致一种Hutchinson-Gilford早老症综合征(Hutchinson-Gilford progeria syndrome,HGPS).一种更严重的早老症——限制性皮肤病(restrictive dermopathy,RD),是由于缺失核层蛋白A前体加工过程中的剪切酶ZMPSTE24引起的.ZMPSTE24的缺失阻止了法尼基化的核层蛋白A前体不能正常加工成为成熟的核层蛋白A,同时导致法尼基化的核层蛋白A前体的堆积.在HGPS和RD病人的成纤维细胞中,发现法尼基化的核层蛋白A前体都定位在核膜,从而影响细胞核膜的完整性,并导致细胞核形的异常,进而导致衰老.最近研究表明经过法尼基酰转移酶抑制剂(famesyltransferase inhibitor,FTI)处理后的细胞的核形异常减少.同时,FTI能够改善HGPS和RD小鼠的早老症状.本文就核层蛋白A前体的法尼基化对衰老的影响有关研究进展作一综述.

  18. Expression of polypeptide GalNAc-transferases in stratified epithelia and squamous cell carcinomas

    DEFF Research Database (Denmark)

    Mandel, U; Hassan, H; Therkildsen, M H

    1999-01-01

    Mucin-type O-glycosylation is initiated by a large family of UDP-GalNAc: polypeptide N -acetyl-galactosaminyltransferases (GalNAc-transferases). Individual GalNAc-transferases appear to have different functions and Northern analysis indicates that they are differently expressed in different organ...

  19. Thermodynamics of Enzyme-Catalyzed Reactions: Part 2. Transferases

    Science.gov (United States)

    Goldberg, Robert N.; Tewari, Yadu B.

    1994-07-01

    Equilibrium constants and enthalpy changes for reactions catalyzed by the transferase class of enzymes have been compiled. For each reaction the following information is given: the reference for the data; the reaction studied; the name of the enzyme used and its Enzyme Commission number; the method of measurement; the conditions of measurement [temperature, pH, ionic strength, and the buffer(s) and cofactor(s) used]; the data and an evaluation of it; and, sometimes, commentary on the data and on any corrections which have been applied to it or any calculations for which the data have been used. The data from 285 references have been examined and evaluated. Chemical Abstract Service registry numbers are given for the substances involved in these various reactions. There is a cross reference between the substances and the Enzyme Commission numbers of the enzymes used to catalyze the reactions in which the substances participate.

  20. Pleiotropic functions of glutathione S-transferase P.

    Science.gov (United States)

    Zhang, Jie; Grek, Christina; Ye, Zhi-Wei; Manevich, Yefim; Tew, Kenneth D; Townsend, Danyelle M

    2014-01-01

    Glutathione S-transferase P (GSTP) is one member of the GST superfamily that is prevalently expressed in mammals. Known to possess catalytic activity through deprotonating glutathione allowing formation of thioether bonds with electrophilic substrates, more recent discoveries have broadened our understanding of the biological roles of this protein. In addition to catalytic detoxification, other properties so far ascribed to GSTP include chaperone functions, regulation of nitric oxide pathways, regulation of a variety of kinase signaling pathways, and participation in the forward reaction of protein S-glutathionylation. The expression of GSTP has been linked with cancer and other human pathologies and more recently even with drug addiction. With respect to human health, polymorphic variants of GSTP may determine individual susceptibility to oxidative stress and/or be critical in the design and development of drugs that have used redox pathways as a discovery platform.

  1. Ghrelin O-Acyl Transferase: Bridging Ghrelin and Energy Homeostasis

    Directory of Open Access Journals (Sweden)

    Andrew Shlimun

    2011-01-01

    Full Text Available Ghrelin O-acyl transferase (GOAT is a recently identified enzyme responsible for the unique n-acyl modification of ghrelin, a multifunctional metabolic hormone. GOAT structure and activity appears to be conserved from fish to man. Since the acyl modification is critical for most of the biological actions of ghrelin, especially metabolic functions, GOAT emerged as a very important molecule of interest. The research on GOAT is on the rise, and several important results reiterating its significance have been reported. Notable among these discoveries are the identification of GOAT tissue expression patterns, effects on insulin secretion, blood glucose levels, feeding, body weight, and metabolism. Several attempts have been made to design and test synthetic compounds that can modulate endogenous GOAT, which could turn beneficial in favorably regulating whole body energy homeostasis. This paper will focus to provide an update on recent advances in GOAT research and its broader implications in the regulation of energy balance.

  2. Glutathione analogue sorbents selectively bind glutathione S-transferase isoenzymes.

    Science.gov (United States)

    Castro, V M; Kelley, M K; Engqvist-Goldstein, A; Kauvar, L M

    1993-06-01

    Novel affinity sorbents for glutathione S-transferases (GSTs) were created by binding glutathione (GSH) analogues to Sepharose 6B. The GSH molecule was modified at the glycine moiety and at the group attached to the sulphur of cysteine. When tested by affinity chromatography in a flow-through microplate format, several of these sorbents selectively bound GST isoenzymes. gamma E-C(Hx)-phi G (glutathione with a hexyl moiety bound to cysteine and phenylglycine substituted for glycine) specifically bound rat GST 7-7, the Pi-class isoenzyme, from liver, kidney and small intestine. gamma E-C(Bz)-beta A (benzyl bound to cysteine and beta-alanine substituted for glycine) was highly selective for rat subunits 3 and 4, which are Mu-class isoenzymes. By allowing purification of the isoenzymes under mild conditions that preserve activity, the novel sorbents should be useful in characterizing the biological roles of GSTs in both normal animal and cancer tissues.

  3. MOF Acetyl Transferase Regulates Transcription and Respiration in Mitochondria.

    Science.gov (United States)

    Chatterjee, Aindrila; Seyfferth, Janine; Lucci, Jacopo; Gilsbach, Ralf; Preissl, Sebastian; Böttinger, Lena; Mårtensson, Christoph U; Panhale, Amol; Stehle, Thomas; Kretz, Oliver; Sahyoun, Abdullah H; Avilov, Sergiy; Eimer, Stefan; Hein, Lutz; Pfanner, Nikolaus; Becker, Thomas; Akhtar, Asifa

    2016-10-20

    A functional crosstalk between epigenetic regulators and metabolic control could provide a mechanism to adapt cellular responses to environmental cues. We report that the well-known nuclear MYST family acetyl transferase MOF and a subset of its non-specific lethal complex partners reside in mitochondria. MOF regulates oxidative phosphorylation by controlling expression of respiratory genes from both nuclear and mtDNA in aerobically respiring cells. MOF binds mtDNA, and this binding is dependent on KANSL3. The mitochondrial pool of MOF, but not a catalytically deficient mutant, rescues respiratory and mtDNA transcriptional defects triggered by the absence of MOF. Mof conditional knockout has catastrophic consequences for tissues with high-energy consumption, triggering hypertrophic cardiomyopathy and cardiac failure in murine hearts; cardiomyocytes show severe mitochondrial degeneration and deregulation of mitochondrial nutrient metabolism and oxidative phosphorylation pathways. Thus, MOF is a dual-transcriptional regulator of nuclear and mitochondrial genomes connecting epigenetics and metabolism.

  4. Experimental conditions affecting functional comparison of highly active glutathione transferases.

    Science.gov (United States)

    Fedulova, Natalia; Mannervik, Bengt

    2011-06-01

    Glutathione transferases (GSTs, EC 2.5.1.18) possess multiple functions and have potential applications in biotechnology. Direct evidence of underestimation of activity of human GST A3-3 and porcine GST A2-2 measured at submicromolar enzyme concentrations is reported here for the first time. The combination of time-dependent and enzyme concentration-dependent loss of activity and the choice of the organic solvent for substrates were found to cause irreproducibility of activity measurements of GSTs. These effects contribute to high variability of activity values of porcine GST A2-2 and human Alpha-class GSTs reported in the literature. Adsorption of GSTs to surfaces was found to be the main explanation of the observed phenomena. Several approaches to improved functional comparison of highly active GSTs are proposed.

  5. From glutathione transferase to pore in a CLIC

    CERN Document Server

    Cromer, B A; Morton, C J; Parker, M W; 10.1007/s00249-002-0219-1

    2002-01-01

    Many plasma membrane chloride channels have been cloned and characterized in great detail. In contrast, very little is known about intracellular chloride channels. Members of a novel class of such channels, called the CLICs (chloride intracellular channels), have been identified over the last few years. A striking feature of the CLIC family of ion channels is that they can exist in a water- soluble state as well as a membrane-bound state. A major step forward in understanding the functioning of these channels has been the recent crystal structure determination of one family member, CLIC1. The structure confirms that CLICs are members of the glutathione S- transferase superfamily and provides clues as to how CLICs can insert into membranes to form chloride channels. (69 refs).

  6. Glutathione transferases: emerging multidisciplinary tools in red and green biotechnology.

    Science.gov (United States)

    Chronopoulou, Evangelia G; Labrou, Nikolaos E

    2009-01-01

    Cytosolic glutathione transferases (GSTs) are a diverse family of enzymes involved in a wide range of biological processes, many of which involve the conjugation of the tripeptide glutathione (GSH) to an electrophilic substrate. Detailed studies of GSTs are justified because of the considerable interest of these enzymes in medicine, agriculture and analytical biotechnology. For example, in medicine, GSTs are explored as molecular targets for the design of new anticancer drugs as a plausible means to sensitize drug-resistant tumors that overexpress GSTs. In agriculture, GSTs are exploited in the development of transgenic plants with increased resistance to biotic and abiotic stresses. Recently, selected isoenzymes of GSTs have found successful applications in the development of enzyme biosensors for the direct monitoring of environmental pollutants, such as herbicides and insecticides. This review article summarizes recent representative patents related to GSTs and their applications in biotechnology.

  7. Inhibition of human glutathione transferases by dinitronaphthalene derivatives.

    Science.gov (United States)

    Groom, Hilary; Lee, Moses; Patil, Pravin; Josephy, P David

    2014-08-01

    Glutathione transferase (GST) enzymes catalyze the conjugation of glutathione with reactive functional groups of endogenous compounds and xenobiotics, including halonitroaromatics. 1-Chloro-2,4-dinitrobenzene (CDNB) is one of the most commonly used substrates for GST activity assays. We have studied the interactions of dinitronaphthalene analogues of CDNB with recombinant human GST enzymes (Alpha, Mu, and Pi classes) expressed in Escherichia coli. Dinitronaphthalene derivatives were found to be GST inhibitors. The highest potency of inhibition was observed towards Mu-class GSTs, M1-1 and M2-2; IC50 values for 1-methoxy- and 1-ethoxy-2,4-dinitronaphthalene were in the high nanomolar to low micromolar range. Inhibition accompanies the formation, at the enzyme active site, of very stable Meisenheimer complex intermediates.

  8. Oral histoplasmosis

    Directory of Open Access Journals (Sweden)

    Patil Karthikeya

    2009-01-01

    Full Text Available Histoplasmosis is a systemic fungal disease that takes various clinical forms, among which oral lesions are rare. The disseminated form of the disease that usually occurs in association with Human Immunodeficiency Virus (HIV is one of the AIDS-defining diseases. Isolated oral histoplasmosis, without systemic involvement, with underlying immunosuppression due to AIDS is very rare. We report one such case of isolated oral histoplasmosis in a HIV-infected patient.

  9. Overexpression of erg20 gene encoding farnesyl pyrophosphate synthase has contrasting effects on activity of enzymes of the dolichyl and sterol branches of mevalonate pathway in Trichoderma reesei.

    Science.gov (United States)

    Piłsyk, Sebastian; Perlińska-Lenart, Urszula; Górka-Nieć, Wioletta; Graczyk, Sebastian; Antosiewicz, Beata; Zembek, Patrycja; Palamarczyk, Grażyna; Kruszewska, Joanna S

    2014-07-10

    The mevalonate pathway is the most diverse metabolic route resulting in the biosynthesis of at least 30,000 isoprenoid compounds, many of which, such as sterols or dolichols, are indispensable for living cells. In the filamentous fungus Trichoderma of major biotechnological interest isoprenoid metabolites are also involved in the biocontrol processes giving the mevalonate pathway an additional significance. On the other hand, little is known about genes coding for enzymes of the mevalonate pathway in Trichoderma. Here, we present cloning and functional analysis of the erg20 gene from Trichoderma reesei coding for farnesyl pyrophosphate (FPP) synthase (EC 2.5.1.10), an enzyme located at the branching point of the mevalonate pathway. Expression of the gene in a thermosensitive erg20-2 mutant of Saccharomyces cerevisiae impaired in the FPP synthase activity suppressed the thermosensitive phenotype. The same gene overexpressed in T. reesei significantly enhanced the FPP synthase activity and also stimulated the activity of cis-prenyltransferase, an enzyme of the dolichyl branch of the mevalonate pathway. Unexpectedly, the activity of squalene synthase from the other, sterol branch, was significantly decreased without, however, affecting ergosterol level.

  10. Interactions between Cigarette Smoking and Polymorphisms of Xenobiotic-Metabolizing Genes: The Risk of Oral Leukoplakia

    Directory of Open Access Journals (Sweden)

    Yu-Fen Li

    2013-01-01

    Full Text Available Background: This case-control study investigates the role of xenobiotic-metabolizing genes, including glutathione S-transferases (GSTs and cytochrome P450 1A1 (CYP1A1 and 2E1 (CYP2E1, in the susceptibility to oral potentially malignant disorders (OPMDs.

  11. Purification and characterization of the commercialized, cloned Bacillus megaterium. alpha. -amylase. Pt. 2. Transferase properties

    Energy Technology Data Exchange (ETDEWEB)

    Brumm, P.J.; Hebeda, R.E.; Teague, W.M.

    1991-08-01

    Using an assay procedure based on reduction of iodine binding to starch, Bacillus megaterium, {alpha}-amylase (BMA) demonstrated transferase activity using a wide range of acceptors. The enzyme had an absolute requirement for glucose or glucosides for acceptor molecules. Maltose acted as a transferase acceptor at low concentrations and as an inhibitor of starch hydrolysis at high concentrations. Kinetic analysis indicated that, in the presence of a suitable acceptor, the mechanism of starch hydrolysis is Ping Pong Bi Bi. The products of the transferase reaction have been determined using p-nitro-{alpha}-D-glucopyranoside as acceptor combined with a novel HPLC-based system for product detection. (orig.).

  12. Resistance to acetaminophen-induced hepatotoxicity in glutathione S-transferase Mu 1-null mice.

    Science.gov (United States)

    Arakawa, Shingo; Maejima, Takanori; Fujimoto, Kazunori; Yamaguchi, Takashi; Yagi, Masae; Sugiura, Tomomi; Atsumi, Ryo; Yamazoe, Yasushi

    2012-01-01

    We investigated the role of glutathione S-transferases Mu 1 (GSTM1) in acetaminophen (APAP)-induced hepatotoxicity using Gstm1-null mice. A single oral administration of APAP resulted in a marked increase in plasma alanine aminotransferase accompanied by hepatocyte necrosis 24 hr after administration in wild-type mice, but its magnitude was unexpectedly attenuated in Gstm1-null mice. Therefore, it is suggested that Gstm1-null mice are resistant to APAP-induced hepatotoxicity. To examine the mechanism of this resistance in Gstm1-null mice, we measured phosphorylation of c-jun N-terminal kinase (JNK), which mediates the signal of APAP-induced hepatocyte necrosis, by Western blot analysis 2 and 6 hr after APAP administration. A marked increase in phosphorylated JNK was observed in wild-type mice, but the increase was markedly suppressed in Gstm1-null mice. Therefore, it is suggested that suppressed phosphorylation of JNK may be a main mechanism of the resistance to APAP-induced hepatotoxicity in Gstm1-null mice, although other possibilities of the mechanism cannot be eliminated. Additionally, phosphorylation of glycogen synthase kinase-3β and mitogen-activated protein kinase kinase 4, which are upstream kinases of JNK in APAP-induced hepatotoxicity, were also suppressed in Gstm1-null mice. A decrease in liver total glutathione 2 hr after APAP administration, which is an indicator for exposure to N-acetyl-p-benzoquinoneimine, the reactive metabolite of APAP, were similar in wild-type and Gstm1-null mice. In conclusion, Gstm1-null mice are considered to be resistant to APAP-induced hepatotoxicity perhaps by the suppression of JNK phosphorylation. This study indicates the novel role of GSTM1 as a factor mediating the cellular signal for APAP-induced hepatotoxicity.

  13. Oral Histoplasmosis.

    Science.gov (United States)

    Folk, Gillian A; Nelson, Brenda L

    2017-02-20

    A 44-year-old female presented to her general dentist with the chief complaint of a painful mouth sore of 2 weeks duration. Clinical examination revealed an irregularly shaped ulcer of the buccal and lingual attached gingiva of the anterior mandible. A biopsy was performed and microscopic evaluation revealed histoplasmosis. Histoplasmosis, caused by Histoplasma capsulate, is the most common fungal infection in the United States. Oral lesions of histoplasmosis are generally associated with the disseminated form of histoplasmosis and may present as a fungating or ulcerative lesion of the oral mucosa. The histologic findings and differential diagnosis for oral histoplasmosis are discussed.

  14. Oral leukoplakia

    DEFF Research Database (Denmark)

    Holmstrup, Palle; Dabelsteen, Erik

    2016-01-01

    The idea of identifying oral lesions with a precancerous nature, i.e. in the sense of pertaining to a pathologic process with an increased risk for future malignant development, of course is to prevent frank malignancy to occur in the affected area. The most common oral lesion with a precancerous...... nature is oral leukoplakia, and for decades it has been discussed how to treat these lesions. Various treatment modalities, such as systemic therapies and surgical removal, have been suggested. The systemic therapies tested so far include retinoids, extracts of green tea, inhibitors of cyclooxygenase-2...

  15. Glutathione Transferase GSTπ In Breast Tumors Evaluated By Three Techniques

    Directory of Open Access Journals (Sweden)

    Rafael Molina

    1993-01-01

    Full Text Available The glutathione transferases are involved in intracellular detoxification reactions. One of these, GSTπ, is elevated in some breast cancer cells, particularly cells selected for resistance to anticancer agents. We evaluated GSTπ expression in 60 human breast tumors by three techniques, immunohistochemistry, Northern hybridization, and Western blot analysis. There was a significant positive correlation between the three methods, with complete concordance seen in 64% of the tumors. There was strong, inverse relationship between GSTπ expression and steroid receptor status with all of the techniques utili zed. [n addition, there was a trend toward higher GSTπ expression in poorly differentiated tumors, but no correlation was found between tumor GSTπ content and DNA ploidy or %S-phase. GSTπ expression was also detected in adjacent benign breast tissue as well as infiltrating lymphocytes; this expression may contribute to GSTπ measurements using either Northern hybridization or Western blot analysis. These re sults suggest that immunohistochemistry is the method of choice for measuring GSTπ in breast tumors.

  16. Benzene oxide is a substrate for glutathione S-transferases.

    Science.gov (United States)

    Zarth, Adam T; Murphy, Sharon E; Hecht, Stephen S

    2015-12-01

    Benzene is a known human carcinogen which must be activated to benzene oxide (BO) to exert its carcinogenic potential. BO can be detoxified in vivo by reaction with glutathione and excretion in the urine as S-phenylmercapturic acid. This process may be catalyzed by glutathione S-transferases (GSTs), but kinetic data for this reaction have not been published. Therefore, we incubated GSTA1, GSTT1, GSTM1, and GSTP1 with glutathione and BO and quantified the formation of S-phenylglutathione. Kinetic parameters were determined for GSTT1 and GSTP1. At 37 °C, the putative Km and Vmax values for GSTT1 were 420 μM and 450 fmol/s, respectively, while those for GSTP1 were 3600 μM and 3100 fmol/s. GSTA1 and GSTM1 did not exhibit sufficient activity for determination of kinetic parameters. We conclude that GSTT1 is a critical enzyme in the detoxification of BO and that GSTP1 may also play an important role, while GSTA1 and GSTM1 seem to be less important.

  17. New substrates and activity of Phanerochaete chrysosporium Omega glutathione transferases.

    Science.gov (United States)

    Meux, Edgar; Morel, Mélanie; Lamant, Tiphaine; Gérardin, Philippe; Jacquot, Jean-Pierre; Dumarçay, Stéphane; Gelhaye, Eric

    2013-02-01

    Omega glutathione transferases (GSTO) constitute a family of proteins with variable distribution throughout living organisms. It is notably expanded in several fungi and particularly in the wood-degrading fungus Phanerochaete chrysosporium, raising questions concerning the function(s) and potential redundancy of these enzymes. Within the fungal families, GSTOs have been poorly studied and their functions remain rather sketchy. In this study, we have used fluorescent compounds as activity reporters to identify putative ligands. Experiments using 5-chloromethylfluorescein diacetate as a tool combined with mass analyses showed that GSTOs are able to cleave ester bonds. Using this property, we developed a specific activity-based profiling method for identifying ligands of PcGSTO3 and PcGSTO4. The results suggest that GSTOs could be involved in the catabolism of toxic compounds like tetralone derivatives. Biochemical investigations demonstrated that these enzymes are able to catalyze deglutathionylation reactions thanks to the presence of a catalytic cysteine residue. To access the physiological function of these enzymes and notably during the wood interaction, recombinant proteins have been immobilized on CNBr Sepharose and challenged with beech wood extracts. Coupled with GC-MS experiments this ligand fishing method allowed to identify terpenes as potential substrates of Omega GST suggesting a physiological role during the wood-fungus interactions.

  18. Inactivation of Anopheles gambiae Glutathione Transferase ε2 by Epiphyllocoumarin

    Directory of Open Access Journals (Sweden)

    Patience Marimo

    2016-01-01

    Full Text Available Glutathione transferases (GSTs are part of a major family of detoxifying enzymes that can catalyze the reductive dehydrochlorination of dichlorodiphenyltrichloroethane (DDT. The delta and epsilon classes of insect GSTs have been implicated in conferring resistance to this insecticide. In this study, the inactivation of Anopheles gambiae GSTε2 by epiphyllocoumarin (Tral 1 was investigated. Recombinant AgGSTε2 was expressed in Escherichia coli cells containing a pET3a-AGSTε2 plasmid and purified by affinity chromatography. Tral 1 was shown to inactivate GSTε2 both in a time-dependent manner and in a concentration-dependent manner. The half-life of GSTε2 in the presence of 25 μM ethacrynic acid (ETA was 22 minutes and with Tral 1 was 30 minutes, indicating that Tral 1 was not as efficient as ETA as an inactivator. The inactivation parameters kinact and KI were found to be 0.020 ± 0.001 min−1 and 7.5 ± 2.1 μM, respectively, after 90 minutes of incubation. Inactivation of GSTε2 by Tral 1 implies that Tral 1 covalently binds to this enzyme in vitro and would be expected to exhibit time-dependent effects on the enzyme in vivo. Tral 1, therefore, would produce irreversible effects when used together with dichlorodiphenyltrichloroethane (DDT in malaria control programmes where resistance is mediated by GSTs.

  19. Glutathione S-transferase, incense burning and asthma in children.

    Science.gov (United States)

    Wang, I-J; Tsai, C-H; Chen, C-H; Tung, K-Y; Lee, Y L

    2011-06-01

    Incense burning is a popular practice in many family homes and temples. However, little is known about the effects of indoor incense burning and genetic polymorphisms on asthma. This study evaluated the effects of indoor incense burning and glutathione S-transferase (GST) genetic polymorphisms on asthma and wheeze. In 2007, 3,764 seventh-grade schoolchildren (mean±sd age 12.42±0.65 yrs) were evaluated using a standard questionnaire for information about respiratory symptoms and environmental exposures. Multiple logistic regressions were performed to assess the association between GST polymorphisms and incense burning frequency on asthma and wheeze, after adjusting for potential confounders. The frequency of incense burning at home was associated with increased risk of current asthma (p=0.05), medication use (p=0.03) and exercise wheeze (p=0.001). GST1 (GSTT1) null genotypes were associated with current asthma (OR 1.43, 95% CI 1.00-2.04) and medication use (OR 1.46, 95% CI 1.01-2.22). GSTT1 showed a significant interactive effect with incense burning on current asthma, current wheeze and nocturnal wheeze. The frequency of incense burning was associated with increased risk of current asthma, medication use, lifetime wheeze, nocturnal wheeze and exercise wheeze in an exposure-response manner among children with GSTT1 null genotype (pIncense burning is a risk factor for asthma and wheezing, especially in GSTT1 genetically susceptible children.

  20. The role of glutathione transferases in renal cell carcinoma

    Directory of Open Access Journals (Sweden)

    Ćorić Vesna

    2016-01-01

    Full Text Available Mounting evidence suggest that members of the subfamily of cytosolic glutathione S-transferases (GSTs possess roles far beyond the classical glutathione-dependent enzymatic conjugation of electrophilic metabolites and xenobiotics. Namely, monomeric forms of certain GSTs are capable of forming protein: protein interactions with protein kinases and regulate cell apoptotic pathways. Due to this dual functionality of cytosolic GSTs, they might be implicated in both the development and the progression of renal cell carcinoma (RCC. Prominent genetic heterogeneity, resulting from the gene deletions, as well as from SNPs in the coding and non-coding regions of GST genes, might affect GST isoenzyme profiles in renal parenchyma and therefore serve as a valuable indicator for predicting the risk of cancer development. Namely, GSTs are involved in the biotransformation of several compounds recognized as risk factors for RCC. The most potent carcinogen of polycyclic aromatic hydrocarbon diol epoxides, present in cigarette smoke, is of benzo(apyrene (BPDE, detoxified by GSTs. So far, the relationship between GST genotype and BPDE-DNA adduct formation, in determining the risk for RCC, has not been evaluated in patients with RCC. Although the association between certain individual and combined GST genotypes and RCC risk has been debated in a the literature, the data on the prognostic value of GST polymorphism in patients with RCC are scarce, probably due to the fact that the molecular mechanism supporting the role of GSTs in RCC progression has not been clarified as yet.

  1. Human glutathione transferases catalyzing the conjugation of the hepatoxin microcystin-LR.

    Science.gov (United States)

    Buratti, Franca M; Scardala, Simona; Funari, Enzo; Testai, Emanuela

    2011-06-20

    Many cyanobacterial species are able to produce cyanotoxins as secondary metabolites. Among them, microcystins (MC) are a group of around 80 congeners of toxic cyclic heptapeptides. MC-LR is the most studied MC congener, in view of its high acute hepatotoxicity and tumor promoting activity. Humans may be exposed to cyanotoxins through several routes, the oral one being the most important. The accepted pathway for MC-LR detoxication and excretion in the urine is GSH conjugation. The GSH adduct (GS-MCLR) formation has been shown to occur spontaneously and enzymatically, catalyzed by glutathione transferases (GSTs). The enzymatic reaction has been reported but not characterized both in vitro and in vivo in animal and plant species. No data are available on humans. In the present work, the MC-LR conjugation with GSH catalyzed by five recombinant human GSTs (A1-1, A3-3, M1-1, P1-1, and T1-1) has been characterized for the first time. All GSTs are able to catalyze the reaction; kinetic parameters K(m), k(cat), and their relative specific activities to form GS-MCLR were derived (T1-1 > A1-1 > M1-1 > A3-3 ≫ P1-1). In the range of MC tested concentrations used (0.25-50 μM) GSTT1-1 and A1-1 showed a typical saturation curve with similar affinity for MC-LR (≈80 μM; k(cat) values 0.18 and 0.10 min(-1), respectively), A3-3 and M1-1 were linear, whereas GSTP1-1 showed a temperature-dependent sigmoidal allosteric curve with a k(cat) = 0.11 min(-1). The enzymes mainly expressed in the liver and gastrointestinal tract, GSTA1-1, T1-1, and M1-1, seemed to be mainly involved in the MC-LR detoxification after oral exposure, whereas P1-1 kinetics and location in the skin suggest a role related to dermal exposure. Considering the high frequency of some GST polymorphism, especially M1 and T1 gene deletion, with complete loss in activity, this information could be the first step to identify groups of individual at higher risk associated with MC exposure.

  2. Oral pathology.

    Science.gov (United States)

    Niemiec, Brook A

    2008-05-01

    Oral disease is exceedingly common in small animal patients. In addition, there is a very wide variety of pathologies that are encountered within the oral cavity. These conditions often cause significant pain and/or localized and systemic infection; however, the majority of these conditions have little to no obvious clinical signs. Therefore, diagnosis is not typically made until late in the disease course. Knowledge of these diseases will better equip the practitioner to effectively treat them. This article covers the more common forms of oral pathology in the dog and cat, excluding periodontal disease, which is covered in its own chapter. The various pathologies are presented in graphic form, and the etiology, clinical signs, recommended diagnostic tests, and treatment options are discussed. Pathologies that are covered include: persistent deciduous teeth, fractured teeth, intrinsically stained teeth, feline tooth resorption, caries, oral neoplasia, eosinophilic granuloma complex, lymphoplasmacytic gingivostomatitis, enamel hypoplasia, and "missing" teeth.

  3. Herpes - oral

    Science.gov (United States)

    ... this page: //medlineplus.gov/ency/article/000606.htm Herpes - oral To use the sharing features on this page, ... 374. Read More Atopic dermatitis Cancer Fever Genital herpes Mouth ulcers Vesicles Review Date 8/14/2015 Updated ...

  4. Disparities in Oral Health

    Science.gov (United States)

    ... 2020: Oral Health Objectives Site Map Disparities in Oral Health Recommend on Facebook Tweet Share Compartir Oral health ... to get and keep dental insurance. Disparities in Oral Health Some of the oral health disparities that exist ...

  5. Serum fucosyl transferase activity and serum fucose levels as diagnostic tools in malignancy.

    Directory of Open Access Journals (Sweden)

    Sen,Umi

    1983-12-01

    Full Text Available Glycoproteins play a significant role in neoplastic transformations. Both the levels of fucose and the activity of fucosyl transferase, which mediates the assembly of the oligosaccharide moieties of the glycoprotein chains, have been found to be elevated in neoplastic conditions. Since these elevations are common features of a variety of neoplastic cells, these two have been designated as non-specific markers of malignancy. In the present study, the fucose level and fucosyl transferase activity were determined in the sera of cancer patients and an attempt was made to establish a relationship between the two. It was found that both the fucose levels and fucosyl transferase activities showed considerable elevation in the five cancer groups studied, establishing them as useful diagnostic parameters. However, it was also observed that the rate of increased fucosyl transferase activity was not fully reflected in the resulting serum fucose levels in a few cases.

  6. 21 CFR 862.1030 - Alanine amino transferase (ALT/SGPT) test system.

    Science.gov (United States)

    2010-04-01

    ... serum and plasma. Alanine amino transferase measurements are used in the diagnosis and treatment of certain liver diseases (e.g., viral hepatitis and cirrhosis) and heart diseases. (b) Classification. Class...

  7. Acetate:succinate CoA-transferase in the hydrogenosomes of Trichomonas vaginalis: Identification and characterization

    NARCIS (Netherlands)

    K.W.A. Grinsven; S. Rosnowsky (Silke); S.W.H. van Weelden (Susanne); S. Pütz (Simone); M. van der Giezen (Mark); W. Martin (William); J.J. van Hellemond (Jaap); A.G.M. Tielens (Aloysius); K. Henze (Katrin)

    2008-01-01

    textabstractAcetate:succinate CoA-transferases (ASCT) are acetate-producing enzymes in hydrogenosomes, anaerobically functioning mitochondria and in the aerobically functioning mitochondria of trypanosomatids. Although acetate is produced in the hydrogenosomes of a number of anaerobic microbial

  8. N-Acetylglutaminoyl-S-farnesyl-L-cysteine (SIG-1191): an anti-inflammatory molecule that increases the expression of the aquaglyceroporin, aquaporin-3, in human keratinocytes.

    Science.gov (United States)

    Fernández, José R; Webb, Corey; Rouzard, Karl; Voronkov, Michael; Huber, Kristen L; Stock, Jeffry B; Stock, Maxwell; Gordon, Joel S; Perez, Eduardo

    2017-03-01

    Isoprenylcysteine (IPC) small molecules were discovered as signal transduction modulating compounds ~25 years ago. More recently, IPC molecules have demonstrated antioxidant and anti-inflammatory properties in a variety of dermal cells as well as antimicrobial activity, representing a novel class of compounds to ameliorate skin conditions and disease. Here, we demonstrate a new IPC compound, N-acetylglutaminoyl-S-farnesyl-L-cysteine (SIG-1191), which inhibits UVB-induced inflammation blocking pro-inflammatory cytokine interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α) production. To investigate further the previously reported hydrating potential of IPC compounds, SIG-1191 was tested for its ability to modulate aquaporin expression. Specifically, aquaporin 3 (AQP3) the most abundant aquaporin found in skin has been reported to play a key role in skin hydration, elasticity and barrier repair. Results show here for the first time that SIG-1191 increases AQP3 expression in both cultured normal human epidermal keratinocytes as well as when applied topically in a three-dimensional (3D) reconstructed human skin equivalent. Additionally, SIG-1191 dose dependently increased AQP3 protein levels, as determined by specific antibody staining, in the epidermis of the 3D skin equivalents. To begin to elucidate which signaling pathways SIG-1191 may be modulating to increase AQP3 levels, we used several pharmacological pathway inhibitors and determined that AQP3 expression is mediated by the Mitogen-activated protein kinase/Extracellular signal-regulated kinase kinase (MEK) pathway. Altogether, these data suggest SIG-1191 represents a new IPC derivative with anti-inflammatory activity that may also promote increased skin hydration based on its ability to increase AQP3 levels.

  9. Glutathione transferase classes alpha, pi, and mu: GSH activation mechanism.

    Science.gov (United States)

    Dourado, Daniel F A R; Fernandes, Pedro Alexandrino; Ramos, Maria João

    2010-10-14

    Since the early 1960s, glutathione transferases (GSTs) have been described as detoxification enzymes. In fact, GSTs are the most important enzymes involved in the metabolism of electrophilic xenobiotic/endobiotic compounds. These enzymes are able to catalyze the nucleophilic addition of glutathione (GSH) sulfur thiolate to a wide range of electrophilic substrates, building up a less toxic and more soluble compound. Cytosolic classes alpha, pi, and mu are the most extensively studied GSTs. However, many of the catalytic events are still poorly understood. In the present work, we have resorted to density functional theory (DFT) and to potential of mean force (PMF) calculations to determine the GSH activation mechanism of GSTP1-1 and GSTM1-1 isoenzymes. For the GSTP1-1 enzyme, we have demonstrated that a water molecule, after an initial conformational rearrangement of GSH, can assist a proton transfer between the GSH cysteine thiol (GSH-SH) and the GSH glutamate alpha carboxylate (GSH-COO(-)) groups. The energy barrier associated with the proton transfer is 11.36 kcal·mol(-1). The GSTM1-1 enzyme shows a completely different behavior from the previous isoenzyme. In this case, two water molecules, positioned between the GSH-SH and the ξ N atom of His107, working like a bridge, are able to promote the proton transfer between these two active groups with an energy barrier of 7.98 kcal·mol(-1). All our results are consistent with all the enzymes kinetics and mutagenesis experimental studies.

  10. Analysis of Arabidopsis glutathione-transferases in yeast.

    Science.gov (United States)

    Krajewski, Matthias P; Kanawati, Basem; Fekete, Agnes; Kowalski, Natalie; Schmitt-Kopplin, Philippe; Grill, Erwin

    2013-07-01

    The genome of Arabidopsis thaliana encodes 54 functional glutathione transferases (GSTs), classified in seven clades. Although plant GSTs have been implicated in the detoxification of xenobiotics, such as herbicides, extensive redundancy within this large gene family impedes a functional analysis in planta. In this study, a GST-deficient yeast strain was established as a system for analyzing plant GSTs that allows screening for GST substrates and identifying substrate preferences within the plant GST family. To this end, five yeast genes encoding GSTs and GST-related proteins were simultaneously disrupted. The resulting yeast quintuple mutant showed a strongly reduced conjugation of the GST substrates 1-chloro-2,4-dinitrobenzene (CDNB) and 4-chloro-7-nitro-2,1,3-benzoxadiazole (NBD-Cl). Consistently, the quintuple mutant was hypersensitive to CDNB, and this phenotype was complemented by the inducible expression of Arabidopsis GSTs. The conjugating activity of the plant GSTs was assessed by in vitro enzymatic assays and via analysis of exposed yeast cells. The formation of glutathione adducts with dinitrobenzene was unequivocally verified by stable isotope labeling and subsequent accurate ultrahigh-resolution mass spectrometry (ICR-FTMS). Analysis of Arabidopsis GSTs encompassing six clades and 42 members demonstrated functional expression in yeast by using CDNB and NBD-Cl as model substrates. Subsequently, the established yeast system was explored for its potential to screen the Arabidopsis GST family for conjugation of the fungicide anilazine. Thirty Arabidopsis GSTs were identified that conferred increased levels of glutathionylated anilazine. Efficient anilazine conjugation was observed in the presence of the phi, tau, and theta clade GSTs including AtGSTF2, AtGSTF4, AtGSTF6, AtGSTF8, AtGSTF10, and AtGSTT2, none of which had previously been known to contribute to fungicide detoxification. ICR-FTMS analysis of yeast extracts allowed the simultaneous detection and

  11. Roles for glutathione transferases in plant secondary metabolism.

    Science.gov (United States)

    Dixon, David P; Skipsey, Mark; Edwards, Robert

    2010-03-01

    Plant glutathione transferases (GSTs) are classified as enzymes of secondary metabolism, but while their roles in catalysing the conjugation and detoxification of herbicides are well known, their endogenous functions are largely obscure. Thus, while the presence of GST-derived S-glutathionylated xenobiotics have been described in many plants, there is little direct evidence for the accumulation of similarly conjugated natural products, despite the presence of a complex and dichotomous metabolic pathway which processes these reaction products. The conservation in glutathione conjugating and processing pathways, the co-regulation of GSTs with inducible plant secondary metabolism and biochemical studies showing the potential of these enzymes to conjugate reactive natural products are all suggestive of important endogenous functions. As a framework for addressing these enigmatic functions we postulate that either: (a) the natural reaction products of GSTs are unstable and undergo reversible S-glutathionylation; (b) the conjugation products of GSTs are very rapidly processed to derived metabolites; (c) GSTs do not catalyse conventional conjugation reactions but instead use glutathione as a cofactor rather than co-substrate; or (d) GSTs are non-catalytic and function as transporter proteins for secondary metabolites and their unstable intermediates. In this review, we describe how enzyme biochemistry and informatics are providing clues as to GST function allowing for the critical evaluation of each of these hypotheses. We also present evidence for the involvement of GSTs in the synthesis of sulfur-containing secondary metabolites such as volatiles and glucosinolates, and the conjugation, transport and storage of reactive oxylipins, phenolics and flavonoids.

  12. Multiple roles for plant glutathione transferases in xenobiotic detoxification.

    Science.gov (United States)

    Cummins, Ian; Dixon, David P; Freitag-Pohl, Stefanie; Skipsey, Mark; Edwards, Robert

    2011-05-01

    Discovered 40 years ago, plant glutathione transferases (GSTs) now have a well-established role in determining herbicide metabolism and selectivity in crops and weeds. Within the GST superfamily, the numerous and plant-specific phi (F) and tau (U) classes are largely responsible for catalyzing glutathione-dependent reactions with xenobiotics, notably conjugation leading to detoxification and, more rarely, bioactivating isomerizations. In total, the crystal structures of 10 plant GSTs have been solved and a highly conserved N-terminal glutathione binding domain and structurally diverse C-terminal hydrophobic domain identified, along with key coordinating residues. Unlike drug-detoxifying mammalian GSTs, plant enzymes utlilize a catalytic serine in place of a tyrosine residue. Both GSTFs and GSTUs undergo changes in structure during catalysis indicative of an induced fit mechanism on substrate binding, with an understanding of plant GST structure/function allowing these proteins to be engineered for novel functions in detoxification and ligand recognition. Several major crops produce alternative thiols, with GSTUs shown to use homoglutathione in preference to glutathione, in herbicide detoxification reactions in soybeans. Similarly, hydroxymethylglutathione is used, in addition to glutathione in detoxifying the herbicide fenoxaprop in wheat. Following GST action, plants are able to rapidly process glutathione conjugates by at least two distinct pathways, with the available evidence suggesting these function in an organ- and species-specific manner. Roles for GSTs in endogenous metabolism are less well defined, with the enzymes linked to a diverse range of functions, including signaling, counteracting oxidative stress, and detoxifying and transporting secondary metabolites.

  13. Regulation of the cardiac muscle ryanodine receptor by glutathione transferases.

    Science.gov (United States)

    Dulhunty, Angela F; Hewawasam, Ruwani; Liu, Dan; Casarotto, Marco G; Board, Philip G

    2011-05-01

    Glutathione transferases (GSTs) are generally recognized for their role in phase II detoxification reactions. However, it is becoming increasingly apparent that members of the GST family also have a diverse range of other functions that are, in general, unrelated to detoxification. One such action is a specific inhibition of the cardiac isoform of the ryanodine receptor (RyR2) intracellular Ca(2+) release channel. In this review, we compare functional and physical interactions between members of the GST family, including GSTO1-1, GSTA1-1, and GSTM2-2, with RyR2 and with the skeletal isoform of the ryanodine receptor (RyR1). The active part of the muscle-specific GSTM2-2 is localized to its nonenzymatic C-terminal α-helical bundle, centered around α-helix 6. The GSTM2-2 binding site is in divergent region 3 (DR3 region) of RyR2. The sequence differences between the DR3 regions of RyR1 and RyR2 explain the specificity of the GSTs for one isoform of the protein. GSTM2-2 is one of the few known endogenous inhibitors of the cardiac RyR and is likely to be important in maintaining low RyR2 activity during diastole. We discuss interactions between a nonenzymatic member of the GST structural family, the CLIC-2 (type 2 chloride intracellular channel) protein, which inhibits both RyR1 and RyR2. The possibility that the GST and CLIC2 proteins bind to different sites on the RyR, and that different structures within the GST and CLIC proteins bind to RyR channels, is discussed. We conclude that the C-terminal part of GSTM2-2 may provide the basis of a therapeutic compound for use in cardiac disorders.

  14. Role of glutathione transferases in the mechanism of brostallicin activation.

    Science.gov (United States)

    Pezzola, Silvia; Antonini, Giovanni; Geroni, Cristina; Beria, Italo; Colombo, Maristella; Broggini, Massimo; Marchini, Sergio; Mongelli, Nicola; Leboffe, Loris; MacArthur, Robert; Mozzi, Alessia Francesca; Federici, Giorgio; Caccuri, Anna Maria

    2010-01-12

    Brostallicin is a novel and unique glutathione transferase-activated pro-drug with promising anticancer activity, currently in phase I and II clinical evaluation. In this work, we show that, in comparison with the parental cell line showing low GST levels, the cytotoxic activity of brostallicin is significantly enhanced in the human breast carcinoma MCF-7 cell line, transfected with either human GST-pi or GST-mu. Moreover, we describe in detail the interaction of brostallicin with GSH in the presence of GSTP1-1 and GSTM2-2, the predominant GST isoenzymes found within tumor cells. The experiments reported here indicate that brostallicin binds reversibly to both isoenzymes with K(d) values in the micromolar range (the affinity being higher for GSTM2-2). Direct evidence that both GSTP1-1 and GSTM2-2 isoenzymes catalyze the Michael addition reaction of GSH to brostallicin has been obtained both by an HPLC-MS technique and by a new fluorometric assay. We also saw the rapid formation of an intermediate reactive species, which is slowly converted into the final products. This intermediate, identified as the alpha-chloroamido derivative of the GSH-brostallicin adduct, is able to alkylate DNA in a sequence-specific manner and appears to be the active form of the drug. The kinetic behavior of the reaction between brostallicin and GSH, catalyzed by GSTP1-1, has been studied in detail, and a minimum kinetic scheme that suitably describes the experimental data is provided. Overall, these data fully support and extend the findings that brostallicin could be indicated for the treatment of tumor overexpressing the pi or mu class GST.

  15. Prediction of substrates for glutathione transferases by covalent docking.

    Science.gov (United States)

    Dong, Guang Qiang; Calhoun, Sara; Fan, Hao; Kalyanaraman, Chakrapani; Branch, Megan C; Mashiyama, Susan T; London, Nir; Jacobson, Matthew P; Babbitt, Patricia C; Shoichet, Brian K; Armstrong, Richard N; Sali, Andrej

    2014-06-23

    Enzymes in the glutathione transferase (GST) superfamily catalyze the conjugation of glutathione (GSH) to electrophilic substrates. As a consequence they are involved in a number of key biological processes, including protection of cells against chemical damage, steroid and prostaglandin biosynthesis, tyrosine catabolism, and cell apoptosis. Although virtual screening has been used widely to discover substrates by docking potential noncovalent ligands into active site clefts of enzymes, docking has been rarely constrained by a covalent bond between the enzyme and ligand. In this study, we investigate the accuracy of docking poses and substrate discovery in the GST superfamily, by docking 6738 potential ligands from the KEGG and MetaCyc compound libraries into 14 representative GST enzymes with known structures and substrates using the PLOP program [ Jacobson Proteins 2004 , 55 , 351 ]. For X-ray structures as receptors, one of the top 3 ranked models is within 3 Å all-atom root mean square deviation (RMSD) of the native complex in 11 of the 14 cases; the enrichment LogAUC value is better than random in all cases, and better than 25 in 7 of 11 cases. For comparative models as receptors, near-native ligand-enzyme configurations are often sampled but difficult to rank highly. For models based on templates with the highest sequence identity, the enrichment LogAUC is better than 25 in 5 of 11 cases, not significantly different from the crystal structures. In conclusion, we show that covalent docking can be a useful tool for substrate discovery and point out specific challenges for future method improvement.

  16. Oral candidiasis.

    Science.gov (United States)

    Millsop, Jillian W; Fazel, Nasim

    2016-01-01

    Oral candidiasis (OC) is a common fungal disease encountered in dermatology, most commonly caused by an overgrowth of Candida albicans in the mouth. Although thrush is a well-recognized presentation of OC, it behooves clinicians to be aware of the many other presentations of this disease and how to accurately diagnose and manage these cases. The clinical presentations of OC can be broadly classified as white or erythematous candidiasis, with various subtypes in each category. The treatments include appropriate oral hygiene, topical agents, and systemic medications. This review focuses on the various clinical presentations of OC and treatment options.

  17. Oral myiasis

    Directory of Open Access Journals (Sweden)

    Treville Pereira

    2010-01-01

    Full Text Available Myiasis is a relatively rare condition arising from the invasion of body tissues or cavities of living animals or humans by maggots or larvae of certain species of flies. It is an uncommon clinical condition, being more frequent in underdeveloped countries and hot climate regions, and is associated with poor hygiene, suppurative oral lesions; alcoholism and senility. Its diagnosis is made basically by the presence of larvae. The present article reports a case of oral myiasis involving 20 larvae in a patient with neurological deficiency.

  18. Characterization of glutathione-S-transferases in zebrafish (Danio rerio).

    Science.gov (United States)

    Glisic, Branka; Mihaljevic, Ivan; Popovic, Marta; Zaja, Roko; Loncar, Jovica; Fent, Karl; Kovacevic, Radmila; Smital, Tvrtko

    2015-01-01

    Glutathione-S-transferases (GSTs) are one of the key enzymes that mediate phase II of cellular detoxification. The aim of our study was a comprehensive characterization of GSTs in zebrafish (Danio rerio) as an important vertebrate model species frequently used in environmental research. A detailed phylogenetic analysis of GST superfamily revealed 27 zebrafish gst genes. Further insights into the orthology relationships between human and zebrafish GSTs/Gsts were obtained by the conserved synteny analysis. Expression of gst genes in six tissues (liver, kidney, gills, intestine, brain and gonads) of adult male and female zebrafish was determined using qRT-PCR. Functional characterization was performed on 9 cytosolic Gst enzymes after overexpression in E. coli and subsequent protein purification. Enzyme kinetics was measured for GSH and a series of model substrates. Our data revealed ubiquitously high expression of gstp, gstm (except in liver), gstr1, mgst3a and mgst3b, high expression of gsto2 in gills and ovaries, gsta in intestine and testes, gstt1a in liver, and gstz1 in liver, kidney and brain. All zebrafish Gsts catalyzed the conjugation of GSH to model GST substrates 1-chloro-2,4-dinitrobenzene (CDNB) and monochlorobimane (MCB), apart from Gsto2 and Gstz1 that catalyzed GSH conjugation to dehydroascorbate (DHA) and dichloroacetic acid (DCA), respectively. Affinity toward CDNB varied from 0.28 mM (Gstp2) to 3.69 mM (Gstm3), while affinity toward MCB was in the range of 5 μM (Gstt1a) to 250 μM (Gstp1). Affinity toward GSH varied from 0.27 mM (Gstz1) to 4.45 mM (Gstt1a). Turnover number for CDNB varied from 5.25s(-1) (Gstt1a) to 112s(-1) (Gstp2). Only Gst Pi enzymes utilized ethacrynic acid (ETA). We suggest that Gstp1, Gstp2, Gstt1a, Gstz1, Gstr1, Mgst3a and Mgst3b have important role in the biotransformation of xenobiotics, while Gst Alpha, Mu, Pi, Zeta and Rho classes are involved in the crucial physiological processes. In summary, this study provides the

  19. Oral calcitonin

    Directory of Open Access Journals (Sweden)

    Hamdy RC

    2012-09-01

    Full Text Available Ronald C Hamdy,1,2 Dane N Daley11Osteoporosis Center, College of Medicine, East Tennessee State University, 2Veterans Affairs Medical Center, Johnson City, TN, USAAbstract: Calcitonin is a hormone secreted by the C-cells of the thyroid gland in response to elevations of the plasma calcium level. It reduces bone resorption by inhibiting mature active osteoclasts and increases renal calcium excretion. It is used in the management of postmenopausal osteoporosis, Paget's disease of bone, and malignancy-associated hypercalcemia. Synthetic and recombinant calcitonin preparations are available; both have similar pharmacokinetic and pharmacodynamic profiles. As calcitonin is a peptide, the traditional method of administration has been parenteral or intranasal. This hinders its clinical use: adherence with therapy is notoriously low, and withdrawal from clinical trials has been problematic. An oral formulation would be more attractive, practical, and convenient to patients. In addition to its effect on active osteoclasts and renal tubules, calcitonin has an analgesic action, possibly mediated through β-endorphins and the central modulation of pain perception. It also exerts a protective action on cartilage and may be useful in the management of osteoarthritis and possibly rheumatoid arthritis. Oral formulations of calcitonin have been developed using different techniques. The most studied involves drug-delivery carriers such as Eligen® 8-(N-2hydroxy-5-chloro-benzoyl-amino-caprylic acid (5-CNAC (Emisphere Technologies, Cedar Knolls, NJ. Several factors affect the bioavailability and efficacy of orally administered calcitonin, including amount of water used to take the tablet, time of day the tablet is taken, and proximity to intake of a meal. Preliminary results looked promising. Unfortunately, in two Phase III studies, oral calcitonin (0.8 mg with 200 mg 5-CNAC, once a day for postmenopausal osteoporosis and twice a day for osteoarthritis failed to

  20. Alteration of glutathione S-transferase properties during the development of Micromelalopha troglodyta larvae (Lepidoptera: Notodontidae)

    Institute of Scientific and Technical Information of China (English)

    TANG Fang; ZHANG Xiu-bo; LIU Yu-sheng; GAO Xi-wu

    2011-01-01

    Micromelalopha troglodyta (Graeser) is an important pest ofpoplar in China. Glutathione S-transferases (GSTs) are known to beresponsible for adaptation mechanisms of M. Troglodyta. The activitiesand kinetic constants of glutathione S-transferases in M. Troglodyta werestudied. Significant differences in glutathione S-transferase activity andkinetic characteristics were observed among five instars of M. Troglodytalarvae. Furthermore, the inhibition of glutathione S-transferase activity infive instars by 24 inhibitors was conducted. The results show the inhibi-tion of GST activity of different instars by 24 inhibitors was different.For GST activity in the 1st instar chlorpyrifos, lambda-cyhalothrin,endosulfan, abamectin, fipronil and pyridaben were the best inhibitorstested, and for GST activity in the 2nd instar, tannic acid and quercetinwere the most potent inhibitors tested, and for GST activity in the 3rdinstar, the inhibitory effects of quercetin, chlorpyrifos andlambda-cyhalothrin were the highest, and for GST activity in the 4thinstar, quercetin and lambda-cyhalothrin were the best inhibitors, and theinhibitory effect of pboxim was the highest for GST activity in the 5thinstar. Our results show that glutathione S-transferases in different iustarsare qualitatively different in isozyme composition and thus different insensitivity to inhibitors.

  1. In vitro and in vivo effects of three different Mitragyna speciosa korth leaf extracts on phase II drug metabolizing enzymes--glutathione transferases (GSTs).

    Science.gov (United States)

    Azizi, Juzaili; Ismail, Sabariah; Mordi, Mohd Nizam; Ramanathan, Surash; Said, Mohd Ikram Mohd; Mansor, Sharif Mahsufi

    2010-01-20

    In the present study, we investigate the effects of three different Mitragyna speciosa extracts, namely methanolic, aqueous and total alkaloid extracts, on glutathione transferase-specific activity in male Sprague Dawley rat liver cytosol in vitro and in vivo. In the in vitro study, the effect of Mitragyna speciosa extracts (0.01 to 750 microg/mL) against the specific activity of glutathione transferases was examined in rat liver cytosolic fraction from untreated rats. Our data show concentration dependent inhibition of cytosolic GSTs when Mitragyna speciosa extract was added into the reaction mixture. At the highest concentration used, the methanolic extract showed the highest GSTs specific activity inhibition (61%), followed by aqueous (50%) and total alkaloid extract (43%), respectively. In in vivo study, three different dosages; 50, 100 and 200 mg/kg for methanolic and aqueous extracts and 5, 10 and 20 mg/kg for total alkaloid extract were given orally for 14 days. An increase in GST specific activity was generally observed. However, only Mitragyna speciosa aqueous extract with a dosage of 100 mg/kg showed significant results: 129% compared to control.

  2. In Vitro and in Vivo Effects of Three Different Mitragyna speciosa Korth Leaf Extracts on Phase II Drug Metabolizing Enzymes—Glutathione Transferases (GSTs

    Directory of Open Access Journals (Sweden)

    Sharif Mahsufi Mansor

    2010-01-01

    Full Text Available In the present study, we investigate the effects of three different Mitragyna speciosa extracts, namely methanolic, aqueous and total alkaloid extracts, on glutathione transferase-specific activity in male Sprague Dawley rat liver cytosol in vitro and in vivo. In the in vitro study, the effect of Mitragyna speciosa extracts (0.01 to 750 µg/mL against the specific activity of glutathione transferases was examined in rat liver cytosolic fraction from untreated rats. Our data show concentration dependent inhibition of cytosolic GSTs when Mitragyna speciosa extract was added into the reaction mixture. At the highest concentration used, the methanolic extract showed the highest GSTs specific activity inhibition (61%, followed by aqueous (50% and total alkaloid extract (43%, respectively. In in vivo study, three different dosages; 50, 100 and 200 mg/kg for methanolic and aqueous extracts and 5, 10 and 20 mg/kg for total alkaloid extract were given orally for 14 days. An increase in GST specific activity was generally observed. However, only Mitragyna speciosa aqueous extract with a dosage of 100 mg/kg showed significant results: 129% compared to control.

  3. Oral Cancer Exam

    Medline Plus

    Full Text Available ... Topics > Oral Cancer > Oral Cancer Exam Video Oral Cancer Exam Video This video shows what happens during an oral cancer examination. Quick and painless, the exam can detect ...

  4. Oral Cancer Exam

    Medline Plus

    Full Text Available ... Topics > Oral Cancer > Oral Cancer Exam Video Oral Cancer Exam Video This video shows what happens during an oral cancer examination. Quick and painless, the exam can detect ...

  5. INDUCTION OF HEPATIC GLUTATHIONE-S-TRANSFERASE ACTIVITY BY Orthosiphon stamineus, BENTH IN STZ-INDUCED DIABETIC RATS

    Directory of Open Access Journals (Sweden)

    J.H. CHIN

    2008-01-01

    Full Text Available The aim of this study was to investigate the acute (one-day treatment effect of a methanol extract of Orthosiphon stamineus, Benth on glutathione-S-transferase (GST activity in streptozotocin (STZ-induced diabetic young male and female Sprague Dawley (SD rats. The methanol extract of O. stamineus was administered orally (5, 31.25, 125 and 500 mg/kg to diabetic rats, and the effect on GST activity was measured by the method of Habig et al. (1974. No lethality and no significant changes in body weight and water intake were observed in the treated group as compared to the control group. A significant increase in the activity of GST was observed in the liver S-9 cytosolic fraction of diabetic male SD rats treated with 125 mg/kg (P < 0.01 and 500 mg/kg (P < 0.01 of the methanol extract O. stamineus. Administration of 500 mg/kg (P < 0.01 of the methanol extract of O. stamineus to diabetic female SD rats increased GST activity when compared to the control group. This study indicates that the methanol extract of O. stamineus could affect the activity of GST in rat liver and the effect seen was dose-dependent

  6. Nuclear translocation of glutathione transferase omega is a progression marker in Barrett's esophagus

    DEFF Research Database (Denmark)

    Piaggi, Simona; Marchi, Santino; Ciancia, Eugenio

    2009-01-01

    Barrett's esophagus (BE) represents a major risk factor for esophageal adenocarcinoma (AC). For this reason, patients with BE are subjected to a systematic endoscopic surveillance to detect initial evolution towards non-invasive neoplasia (NiN) and cancer, that eventually occurs only in a small f...... fraction of BE patients. This study was aimed to investigate the possible role of glutathione-S-transferase-omega 1 (GSTO1), a recently discovered member of the glutathione-S-transferase family, as a progression marker in the Barrett's disease in order to improve the diagnosis of Ni...... equally divided between nuclear, cytoplasmic and diffuse staining (2 each, respectively). Experiments in vitro showed that in human HeLa cancer cells, GSTO1 translocates into the nucleus as a consequence of heath shock. These findings suggested that the nuclear translocation of glutathione-S-transferase-omega...

  7. Glutathione transferases and development of new principles to overcome drug resistance.

    Science.gov (United States)

    Sau, Andrea; Pellizzari Tregno, Francesca; Valentino, Francesco; Federici, Giorgio; Caccuri, Anna Maria

    2010-08-15

    Chemoresistance is a multifactorial phenomenon and many studies clearly show that a coordinated expression of efflux transporter proteins and phase II conjugating enzymes in tumor cells is linked to the development of the multidrug resistance phenotype. In particular, the overexpression of glutathione S-transferases and efflux pumps in tumors may reduce the reactivity of various anticancer drugs. In recent years it has become evident that glutathione S-transferases are also involved in the control of apoptosis through the inhibition of the JNK signaling pathway. As such, the glutathione S-transferase superfamily has become the focus of extensive pharmaceutical research in attempt to generate more efficient anticancer agents. Here we present an overview of the GST inhibitors and the GST-activated pro-drugs utilized to date to overcome drug resistance.

  8. Oral dirofilariasis

    Directory of Open Access Journals (Sweden)

    R S Desai

    2015-01-01

    Full Text Available Dirofilaria is parasitic nematodes of domestic and wild animals that can infect humans accidentally via vectors. Its occurrence in the oral cavity is extremely rare. The most frequent presentation of human dirofilariasis is a single submucosal nodule without signs of inflammation. We hereby, report a case of human dirofilariasis affecting the buccal mucosa in a 32-year-old farmer caused by D. repens.

  9. Oral leiomyomas.

    Science.gov (United States)

    Damm, D D; Neville, B W

    1979-04-01

    Oral leiomyomas are considered to be rare neoplasms, but they may be encountered more frequently than generally believed. Three types of leiomyomas are commonly described: solid leiomyomas, angiomyomas, and epithelioid leiomyomas. Three cases of solid leiomyoma are presented, all of which occurred in the anterior mandibular mucobuccal fold. Leiomyomas can be easily confused with other spindle-cell tumors. The necessity of using special stains, especially Mallory's phosphotungstic acid hematoxylin, is discussed.

  10. ABO blood group antigens in oral mucosa. What is new?

    DEFF Research Database (Denmark)

    Dabelsteen, Erik

    2002-01-01

    which represent secondary gene products. They are synthesized in a stepwise fashion from a precursor by the action of different glycosyltransferases. In non-keratinized oral mucosa, a sequential elongation of the carbohydrates is associated with differentiation of epithelial cells, resulting...... in expression of precursors on basal cells and A/B antigens on spinous cells. Reduction or complete deletion of A/B antigen expression in oral carcinomas has been reported, a phenotypic change that is correlated with invasive and metastatic potential of the tumours and with the mortality rates of the patients....... Disappearance of the antigens is ascribed to the absence of A or B transferase gene expression. Several studies have shown that loss of A and B antigen expression is associated with increased cell motility, invasion in matrigel, and tumourigenecity in syngenic animals. In vivo studies of human oral wound...

  11. Activity Detection of GalNAc Transferases by Protein-Based Fluorescence Sensors In Vivo.

    Science.gov (United States)

    Song, Lina; Bachert, Collin; Linstedt, Adam D

    2016-01-01

    Mucin-type O-glycosylation occurring in the Golgi apparatus is an important protein posttranslational modification initiated by up to 20 GalNAc-transferase isozymes with largely distinct substrate specificities. Regulation of this enzyme family affects a vast array of proteins transiting the secretory pathway and misregulation causes human diseases. Here we describe the use of protein-based fluorescence sensors that traffic in the secretory pathway to monitor GalNAc-transferase activity in living cells. The sensors can either be "pan" or isozyme specific.

  12. Mapping of amino acid substitutions conferring herbicide resistance in wheat glutathione transferase.

    Science.gov (United States)

    Govindarajan, Sridhar; Mannervik, Bengt; Silverman, Joshua A; Wright, Kathy; Regitsky, Drew; Hegazy, Usama; Purcell, Thomas J; Welch, Mark; Minshull, Jeremy; Gustafsson, Claes

    2015-03-20

    We have used design of experiments (DOE) and systematic variance to efficiently explore glutathione transferase substrate specificities caused by amino acid substitutions. Amino acid substitutions selected using phylogenetic analysis were synthetically combined using a DOE design to create an information-rich set of gene variants, termed infologs. We used machine learning to identify and quantify protein sequence-function relationships against 14 different substrates. The resulting models were quantitative and predictive, serving as a guide for engineering of glutathione transferase activity toward a diverse set of herbicides. Predictive quantitative models like those presented here have broad applicability for bioengineering.

  13. Origin and evolution of the Peptidyl Transferase Center from proto-tRNAs

    Directory of Open Access Journals (Sweden)

    Sávio T. Farias

    2014-01-01

    Full Text Available We tested the hypothesis of Tamura (2011 [3] that molecules of tRNA gave origin to ribosomes, particularly to the Peptidyl Transferase Center (PTC of the 23S ribosomal RNA. We reconstructed the ancestral sequences from all types of tRNA and compared them in their sequences with the current PTC of 23S ribosomal RNA from different organisms. We built an ancestral sequence of proto-tRNAs that showed a remarkable overall identity of 50.53% with the catalytic site of PTC. We conclude that the Peptidyl Transferase Center was indeed originated by the fusion of ancestral sequences of proto-tRNA.

  14. Cholesterol oxides inhibit cholesterol esterification by lecithin: cholesterol acyl transferase

    Directory of Open Access Journals (Sweden)

    Eder de Carvalho Pincinato

    2009-09-01

    Full Text Available Cholesterol oxides are atherogenic and can affect the activity of diverse important enzymes for the lipidic metabolism. The effect of 7β-hydroxycholesterol, 7-ketocholesterol, 25-hydroxycholesterol, cholestan-3β,5α,6β-triol,5,6β-epoxycholesterol, 5,6α-epoxycholesterol and 7α-hydroxycholesterol on esterification of cholesterol by lecithin:cholesterol acyl transferase (LCAT, EC 2.3.1.43 and the transfer of esters of cholesterol oxides from high density lipoprotein (HDL to low density lipoproteins (LDL and very low density lipoproteins (VLDL by cholesteryl ester transfer protein (CETP was investigated. HDL enriched with increasing concentrations of cholesterol oxides was incubated with fresh plasma as source of LCAT. Cholesterol and cholesterol oxides esterification was followed by measuring the consumption of respective free sterol and oxysterols. Measurements of cholesterol and cholesterol oxides were done by gas-chromatography. 14C-cholesterol oxides were incorporated into HDL2 and HDL3 subfractions and then incubated with fresh plasma containing LCAT and CETP. The transfer of cholesterol oxide esters was followed by measuring the 14C-cholesterol oxide-derived esters transferred to LDL and VLDL. All the cholesterol oxides studied were esterified by LCAT after incorporation into HDL particles, competing with cholesterol by LCAT. Cholesterol esterification by LCAT was inversely related to the cholesterol oxide concentration. The esterification of 14C-cholesterol oxides was higher in HDL3 and the transfer of the derived esters was greater from HDL2 to LDL and VLDL. The results suggest that cholesterol esterification by LCAT is inhibited in cholesterol oxide-enriched HDL particles. Moreover, the cholesterol oxides-derived esters are efficiently transferred to LDL and VLDL. Therefore, we suggest that cholesterol oxides may exert part of their atherogenic effect by inhibiting cholesterol esterification on the HDL surface and thereby disturbing

  15. Purification and Biochemical Characterization of Glutathione S-Transferase from Down Syndrome and Normal Children Erythrocytes: A Comparative Study

    Science.gov (United States)

    Hamed, Ragaa R.; Maharem, Tahany M.; Abdel-Meguid, Nagwa; Sabry, Gilane M.; Abdalla, Abdel-Monem; Guneidy, Rasha A.

    2011-01-01

    Down syndrome (DS) is the phenotypic manifestation of trisomy 21. Our study was concerned with the characterization and purification of glutathione S-transferase enzyme (GST) from normal and Down syndrome (DS) erythrocytes to illustrate the difference in the role of this enzyme in the cell. Glutathione S-transferase and glutathione (GSH) was…

  16. Oral contraceptives.

    Science.gov (United States)

    Maclennan, A H

    1987-12-01

    Over 60 million women use highly efficient and safe modern combined oral contraceptives (OCs) every day. A women who takes the oral contraceptive for 5 years before the age of 30 will actually live 12 days longer, although a woman taking the pill for the 1st time for 5 years after the age of 30 will have her life span reduced on the average by 80 days. OC related morbidity and mortality mostly occur in women over 35 who smoke. Combined low dose OCs are safe for women who do not smoke, at least to 45 years of age and probably to the menopause. The prescription of OCs is also safe to the young adolescent. The pill does not interfere with maturation of the hypothalamic-pituitary ovarian axis and does not increase the incidence of amenorrhoea, oligomenorrhoea or infertility in later life. Patients with contraindications to estrogen therapy are excluded from OC use (history of thromboembolism, major heart disease, liver disease, breast cancer). Low-dose (30-35 mcg estrogen-containing monophasic or triphasic) pills are recommended. Combined oral contraceptives contain either ethinyl estradiol (1.7 to 2 times more potent) or mestranol. After absorption the progestagens, norethisterone acetate, ethynodiol diacetate and lynoestrenol are all metabolized to norethisterone. The progestagen-only pill has about a 2% failure rate and poorer cycle control than the combined pill, but it lacks estrogenic, progestagenic and androgenic side effects. This pill is suitable for the lactating mother, for smokers over 35, for hypertensive patients, and for those with a history of thrombosis. The efficacy of the progestagen-only pill is restored in 3 days of pill taking. Postcoital contraception is an alternative: treatment can be given for at least 72 hours after intercourse. The Yuzpe method calls for the patient to take 2 combined oral contraceptive tablets containing levonorgestrel and ethinyl estradiol (Eugynon or Ovral) followed by a further 2 tablets 12 hours later. This regimen

  17. Purification of human hepatic glutathione S-transferases and the development of a radioimmunoassay for their measurement in plasma

    Energy Technology Data Exchange (ETDEWEB)

    Hayes, J.D.; Gilligan, D.; Beckett, G.J. (Edinburgh Univ. (UK). Dept. of Clinical Chemistry); Chapman, B.J. (Royal Infirmary, Edinburgh (UK))

    1983-10-31

    A purification scheme is described for six human hepatic glutathione S-transferases from a single liver. Five of the transferases comprised Ya monomers and had a molecular mass of 44000. The remaining enzyme comprised Yb monomers and had a molecular mass of 47000. Data are presented demonstrating that there are at least two distinct Ya monomers. A radioimmunoassay has been developed that has sufficient precision and sensitivity to allow direct measurement of glutathione S-transferase concentrations in unextracted plasma. A comparison of aminotransferase and glutathione S-transferase levels, in three patients who had taken a paracetamol overdose, indicated that glutathione S-transferase measurements provided a far more sensitive index of hepatocellular integrity than the more conventional aminotransferase measurements.

  18. Partial hypoxanthine-guanine phosphoribosyl transferase deficiency without elevated urinary hypoxanthine excretion

    NARCIS (Netherlands)

    van Dael, C. M. L.; Pierik, L. J. W. M.; Reijngoud, D. J.; Niezen-Koning, K. E.; van Diggelen, O. P.; van Spronsen, F. J.

    Partial hypoxanthine-guanine phosphoribosyl transferase (HGPRT) deficiency, also known as the Kelley-Seegmiller syndrome, can give rise to a wide range of neurological symptoms, and renal insufficiency. Biochemically, it is characterized by high uric acid concentrations in blood, high uric acid and

  19. Antibiotic inhibition of the movement of tRNA substrates through a peptidyl transferase cavity

    DEFF Research Database (Denmark)

    Porse, B T; Rodriguez-Fonseca, C; Leviev, I

    1996-01-01

    The present review attempts to deal with movement of tRNA substrates through the peptidyl transferase centre on the large ribosomal subunit and to explain how this movement is interrupted by antibiotics. It builds on the concept of hybrid tRNA states forming on ribosomes and on the observed movem...

  20. Development of isoform-specific sensors of polypeptide GalNAc-transferase activity.

    Science.gov (United States)

    Song, Lina; Bachert, Collin; Schjoldager, Katrine T; Clausen, Henrik; Linstedt, Adam D

    2014-10-31

    Humans express up to 20 isoforms of GalNAc-transferase (herein T1-T20) that localize to the Golgi apparatus and initiate O-glycosylation. Regulation of this enzyme family affects a vast array of proteins transiting the secretory pathway and diseases arise upon misregulation of specific isoforms. Surprisingly, molecular probes to monitor GalNAc-transferase activity are lacking and there exist no effective global or isoform-specific inhibitors. Here we describe the development of T2- and T3-isoform specific fluorescence sensors that traffic in the secretory pathway. Each sensor yielded little signal when glycosylated but was strongly activated in the absence of its glycosylation. Specificity of each sensor was assessed in HEK cells with either the T2 or T3 enzymes deleted. Although the sensors are based on specific substrates of the T2 and T3 enzymes, elements in or near the enzyme recognition sequence influenced their activity and required modification, which we carried out based on previous in vitro work. Significantly, the modified T2 and T3 sensors were activated only in cells lacking their corresponding isozymes. Thus, we have developed T2- and T3-specific sensors that will be valuable in both the study of GalNAc-transferase regulation and in high-throughput screening for potential therapeutic regulators of specific GalNAc-transferases.

  1. 21 CFR 573.130 - Aminoglycoside 3′-phospho- transferase II.

    Science.gov (United States)

    2010-04-01

    ... SERVICES (CONTINUED) ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS FOOD ADDITIVES PERMITTED IN FEED AND DRINKING WATER OF ANIMALS Food Additive Listing § 573.130 Aminoglycoside 3′-phospho- transferase II. The...) which catalyzes the phosphorylation of certain aminoglycoside antibiotics, including kanamycin,...

  2. Effect of glutathione S-transferases on the survival of patients with acute myeloid leukaemia

    DEFF Research Database (Denmark)

    Autrup, Judith; Hokland, Peter; Pedersen, Lars

    2002-01-01

    The objective of the study was to investigate the effect of genetic polymorphisms in glutathione S-transferases (GST) on the survival of acute myeloid leukaemia patients receiving adriamycin induction therapy. A total of 89 patients were included in the study. Patients who carried at least one GS...

  3. Global deletion of glutathione S-Transferase A4 exacerbates developmental nonalcoholic steatohepatitis

    Science.gov (United States)

    We established a mouse model of developmental nonalcoholic steatohepatitis (NASH) by feeding a high polyunsaturated fat liquid diet to female glutathione-S-transferase 4-4 (Gsta4-/-)/peroxisome proliferator activated receptor a (Ppara-/-) double knockout 129/SvJ mice for 12 weeks from weaning. We us...

  4. Glutathione transferase activity and oocyte development in copepods exposed to toxic phytoplankton

    DEFF Research Database (Denmark)

    Kozlowsky-Suzuki, Betina; Koski, Marja; Hallberg, Eric

    2009-01-01

    Organisms present a series of cellular mechanisms to avoid the effects of toxic compounds. Such mechanisms include the increase in activity of detoxification enzymes [e.g., 7-ethoxyresorufin-O-deethylase (EROD) and glutathione S-transferase (GST)I, which could explain the low retention of ingeste...

  5. Glutathione S-transferase polymorphisms in allergic contact dermatitis to xenobiotics

    NARCIS (Netherlands)

    Pot, L.M.; Alizadeh, B.Z.; Laizane, D.; Coenraads, P.J.; Snieder, H.; Blömeke, B.

    2010-01-01

    Background: Xenobiotics, such as para-phenylenediamine (PPD), are thought to be detoxified by phase II enzymes, like the Glutathione S-transferases (GSTs). The human cytosolic GSTs display polymorphisms which are likely to contribute to interindividual differences in responses to xenobiotics. By per

  6. Preliminary X-ray crystallographic analysis of glutathione transferase zeta 1 (GSTZ1a-1a)

    Energy Technology Data Exchange (ETDEWEB)

    Boone, Christopher D.; Zhong, Guo; Smeltz, Marci; James, Margaret O., E-mail: mojames@ufl.edu; McKenna, Robert, E-mail: mojames@ufl.edu

    2014-01-21

    Crystals of glutathione transferase zeta 1 were grown and shown to diffract X-rays to 3.1 Å resolution. They belonged to space group P1, with unit-cell parameters a = 42.0, b = 49.6, c = 54.6 Å, α = 82.9, β = 69.9, γ = 73.4°.

  7. A practical fluorogenic substrate for high-throughput screening of glutathione S-transferase inhibitors.

    Science.gov (United States)

    Fujikawa, Yuuta; Morisaki, Fumika; Ogura, Asami; Morohashi, Kana; Enya, Sora; Niwa, Ryusuke; Goto, Shinji; Kojima, Hirotatsu; Okabe, Takayoshi; Nagano, Tetsuo; Inoue, Hideshi

    2015-07-21

    We report a new fluorogenic substrate for glutathione S-transferase (GST), 3,4-DNADCF, enabling the assay with a low level of nonenzymatic background reaction. Inhibitors against Noppera-bo/GSTe14 from Drosophila melanogaster were identified by high throughput screening using 3,4-DNADCF, demonstrating the utility of this substrate.

  8. Partial hypoxanthine-guanine phosphoribosyl transferase deficiency without elevated urinary hypoxanthine excretion

    NARCIS (Netherlands)

    van Dael, C. M. L.; Pierik, L. J. W. M.; Reijngoud, D. J.; Niezen-Koning, K. E.; van Diggelen, O. P.; van Spronsen, F. J.

    2007-01-01

    Partial hypoxanthine-guanine phosphoribosyl transferase (HGPRT) deficiency, also known as the Kelley-Seegmiller syndrome, can give rise to a wide range of neurological symptoms, and renal insufficiency. Biochemically, it is characterized by high uric acid concentrations in blood, high uric acid and

  9. Molecular cloning and expression of several new Anopheles cracens epsilon class glutathione transferases.

    Science.gov (United States)

    Wongtrakul, Jeerang; Wongsantichon, Jantana; Vararattanavech, Ardcharaporn; Leelapat, Posri; Prapanthadara, La-aied; Ketterman, Albert J

    2009-01-01

    Glutathione transferases, GSTs, are detoxification proteins that are found in most organisms. The acGSTE3-3 had the ability to conjugate 4-hydroxynonenal, a cytotoxic lipid peroxidation product. Although other Epsilon GSTs showed roles in insecticide metabolism, the acGSTE3-3 appeared to have a major role in detoxifying lipid peroxidation products conferring protection against oxidative damage.

  10. Chromosomal localization of the gene for the human Theta class glutathione transferase (GSTT1)

    Energy Technology Data Exchange (ETDEWEB)

    Webb, G.; Vaska, V. [Queen Elizabeth Hospital, Adelaide (Australia); Goggan, M.; Board, P. [Australian National Univ., Canberra (Australia)

    1996-04-01

    Two loci encoding Theta class glutathione transferases (GSTs) have been identified in humans. In situ hybridization studies have localized the GSTT1 gene to 22q11.2. This is the same band to which we previously localized the GSTT2 gene. This finding confirms the trend for human GST genes to be found in class-specific clusters. 20 refs., 1 fig.

  11. Maize white seedling 3 results from disruption of homogentisate solanesyl transferase

    Science.gov (United States)

    Maize white seedling 3 (w3) has served as a model albino-seedling mutant since its discovery in 1923. We show here that the w3 phenotype is caused by disruptions in homogentisate solanesyl transferase (HST), an enzyme that catalyzes the committed step in plastoquinone-9 (PQ9) biosynthesis. This re...

  12. Development of isoform-specific sensors of polypeptide GalNAc-transferase activity

    DEFF Research Database (Denmark)

    Song, Lina; Bachert, Collin; Schjoldager, Katrine T

    2014-01-01

    Humans express up to 20 isoforms of GalNAc-transferase (herein T1-T20) that localize to the Golgi apparatus and initiate O-glycosylation. Regulation of this enzyme family affects a vast array of proteins transiting the secretory pathway and diseases arise upon misregulation of specific isoforms...

  13. Inhibition of rat, mouse, and human glutathione S-transferase by eugenol and its oxidation products

    NARCIS (Netherlands)

    Rompelberg, C.J.M.; Ploemen, J.H.T.M.; Jespersen, S.; Greef, J. van der; Verhagen, H.; Bladeren, P.J. van

    1996-01-01

    The irreversible and reversible inhibition of glutathione S-transferases (GSTs) by eugenol was studied in rat, mouse and man. Using liver cytosol of human, rat and mouse, species differences were found in the rate of irreversible inhibition of GSTs by eugenol in the presence of the enzyme tyrosinase

  14. Galactose-1-phosphate uridyl transferase deficiency is not associated with Mullerian aplasia in Dutch patients.

    NARCIS (Netherlands)

    Nijland, R.; Hartog, F.E.; Wevers, R.A.; Wanders, R.J.; Willemsen, W.N.P.

    2009-01-01

    STUDY OBJECTIVE: To study whether a deficiency in galactose-1-phosphate uridyl transferase (GALT) activity of mothers was an explanation for the occurrence of Mullerian aplasia of their daughters. DESIGN: A case control study. SETTING: The patients were selected from the outpatient clinic of the Uni

  15. Glutathione S-transferase isoenzymes in relation to their role in detoxification of xenobiotics.

    NARCIS (Netherlands)

    Vos, R.M.E.

    1989-01-01

    The glutathione S-transferases (GST) are a family of isoenzymes serving a major part in the biotransformation of many reactive compounds. The isoenzymes from rat, man and mouse are divided into three classes, alpha, mu and pi, on the basis of similar structural and enzymatic properties.

  16. Functional characterization of glutathione S-transferases associated with insecticide resistance in Tetranychus urticae

    NARCIS (Netherlands)

    Pavlidi, N.; Tseliou, V.; Riga, M.; Nauen, R.; Van Leeuwen, T.; Labrou, N.E.; Vontas, J.

    2015-01-01

    The two-spotted spider mite Tetranychus urticae is one of the most important agricultural pests world-wide. It is extremely polyphagous and develops resistance to acaricides. The overexpression of several glutathione S-transferases (GSTs) has been associated with insecticide resistance. Here, we fun

  17. Functional characterization of glutathione S-transferases associated with insecticide resistance in Tetranychus urticae

    NARCIS (Netherlands)

    Pavlidi, N.; Tseliou, V.; Riga, M.; Nauen, R.; Van Leeuwen, T.; Labrou, N.E.; Vontas, J.

    2015-01-01

    The two-spotted spider mite Tetranychus urticae is one of the most important agricultural pests world-wide. It is extremely polyphagous and develops resistance to acaricides. The overexpression of several glutathione S-transferases (GSTs) has been associated with insecticide resistance. Here, we

  18. Inhibition of human glutathione S-transferase P1-1 by the flavonoid quercetin

    NARCIS (Netherlands)

    Zanden, J.J. van; Hamman, O.B.; Iersel, M.L.P.S. van; Boeren, S.; Cnubben, N.H.P.; Lo Bello, M.; Vervoort, J.; Bladeren, P.J. van; Rietjens, I.M.C.M.

    2003-01-01

    In the present study, the inhibition of human glutathione S-transferase P1-1 (GSTP1-1) by the flavonoid quercetin has been investigated. The results show a time- and concentration-dependent inhibition of GSTP1-1 by quercetin. GSTP1-1 activity is completely inhibited upon 1 h incubation with 100 μM q

  19. The phosphopantetheinyl transferases: catalysis of a post-translational modification crucial for life

    DEFF Research Database (Denmark)

    Beld, Joris; Sonnenschein, Eva; Vickery, Christopher R.;

    2013-01-01

    Covering: up to 2013 Although holo-acyl carrier protein synthase, AcpS, a phosphopantetheinyl transferase (PPTase), was characterized in the 1960s, it was not until the publication of the landmark paper by Lambalot et al. in 1996 that PPTases garnered wide-spread attention being classified as a d...

  20. Acetate:succinate CoA-transferase in the hydrogenosomes of Trichomonas vaginalis: Identification and characterization

    NARCIS (Netherlands)

    K.W.A. Grinsven; S. Rosnowsky (Silke); S.W.H. van Weelden (Susanne); S. Pütz (Simone); M. van der Giezen (Mark); W. Martin (William); J.J. van Hellemond (Jaap); A.G.M. Tielens (Aloysius); K. Henze (Katrin)

    2008-01-01

    textabstractAcetate:succinate CoA-transferases (ASCT) are acetate-producing enzymes in hydrogenosomes, anaerobically functioning mitochondria and in the aerobically functioning mitochondria of trypanosomatids. Although acetate is produced in the hydrogenosomes of a number of anaerobic microbial euka

  1. Farnesyl pyrophosphate synthase enantiospecificity with a chiral risedronate analog, [6,7-dihydro-5H-cyclopenta[c]pyridin-7-yl(hydroxy)methylene]bis(phosphonic acid) (NE-10501): Synthetic, structural, and modeling studies

    Energy Technology Data Exchange (ETDEWEB)

    Deprele, Sylvine; Kashemirov, Boris A.; Hogan, James M.; Ebetino, Frank H.; Barnett, Bobby L.; Evdokimov, Artem; McKenna, Charles E. (USC); (UCIN); (PG)

    2008-08-19

    The complex formed from crystallization of human farnesyl pyrophosphate synthase (hFPPS) from a solution of racemic [6,7-dihydro-5H-cyclopenta[c]pyridin-7-yl(hydroxy)methylene]bis(phosphonic acid) (NE-10501, 8), a chiral analog of the anti-osteoporotic drug risedronate, contained the R enantiomer in the enzyme active site. This enantiospecificity was assessed by computer modeling of inhibitor-active site interactions using Autodock 3, which was also evaluated for predictive ability in calculations of the known configurations of risedronate, zoledronate, and minodronate complexed in the active site of hFPPS. In comparison with these structures, the 8 complex exhibited certain differences, including the presence of only one Mg{sup 2+}, which could contribute to its 100-fold higher IC{sub 50}. An improved synthesis of 8 is described, which decreases the number of steps from 12 to 8 and increases the overall yield by 17-fold.

  2. Oral dirofilariasis

    Directory of Open Access Journals (Sweden)

    Mahija Janardhanan

    2014-01-01

    Full Text Available Filariasis affecting animals can rarely cause infections in human beings through the accidental bite of potential vectors. The resulting infection in man, known as zoonotic filariasis occur worldwide. Human dirofilariasis, the most common zoonotic filariasis, is caused by the filarial worm belonging to the genus Dirofilaria. Dirofilarial worms, which are recognized as pathogenic in man can cause nodular lesions in the lung, subcutaneous tissue, peritoneal cavity or eyes. Oral dirofilariasis is extremely rare and only a few cases have been documented. We report an interesting case of dirofilariasis due to Dirofilaria repens involving buccal mucosa in a patient who presented with a facial swelling. The clinical features, diagnostic issues and treatment aspects are discussed. This paper stresses the importance of considering dirofilariasis as differential diagnosis for subcutaneous swelling of the face, especially in areas where it is endemic.

  3. Oral sex, oral health and orogenital infections

    Directory of Open Access Journals (Sweden)

    Saini Rajiv

    2010-01-01

    Full Text Available Oral sex is commonly practiced by sexually active male-female and same-gender couples of various ages, including adolescents. The various type of oral sex practices are fellatio, cunnilingus and analingus. Oral sex is infrequently examined in research on adolescents; oral sex can transmit oral, respiratory, and genital pathogens. Oral health has a direct impact on the transmission of infection; a cut in your mouth, bleeding gums, lip sores or broken skin increases chances of infection. Although oral sex is considered a low risk activity, it is important to use protection and safer sex precautions. There are various methods of preventing infection during oral sex such as physical barriers, health and medical issues, ethical issues and oral hygiene and dental issues. The lesions or unhealthy periodontal status of oral cavity accelerates the phenomenon of transmission of infections into the circulation. Thus consequences of unhealthy or painful oral cavity are significant and oral health should be given paramount importance for the practice of oral sex.

  4. Oral amyloidosis

    Directory of Open Access Journals (Sweden)

    Isabella Lima Arrais Ribeiro

    Full Text Available A amiloidose é uma doença complexa rara de difícil diagnóstico que ocorre devido à deposição de substância amilóide no meio extracelular. Ao ser diagnosticado na cavidade bucal, deve-se monitorar o paciente a fim de avaliar possíveis complicações sistêmicas da doença. Diante disso, o objetivo do presente estudo é relatar um caso de amiloidose oral em uma paciente do gênero feminino de 72 anos de idade. Baseado nos sinais clínicos observados, a hipótese diagnóstica foi de fibroma traumático. Após realização de biópsia e exame histopatológico, o diagnóstico foi de amiloidose oral, o que foi confirmado com a coloração do espécime com o reagente vermelho congo. Depósitos de amilóide foram encontrados no tecido conjuntivo, na avaliação através da luz polarizada, que apresentou birrefringência. Tal achado foi preocupante, já que a amiloidose geralmente acomete diversos tecidos levando a comprometimentos sistêmicos. Por essa razão a paciente foi encaminhada a procurar atendimento médico. No entanto, houve abandono do tratamento e a mesma veio a óbito 6 meses após o diagnóstico da doença. Lesões orais aparentemente simples podem revelar doenças raras e de difícil tratamento. O diagnóstico preciso e acompanhamentos médicos são fundamentais na sobrevida do paciente.

  5. Role of genetic polymorphism of glutathione-s-transferase T1 and microsomal epoxide hydrolase in aflatoxin-associated hepatocellular carcinoma

    NARCIS (Netherlands)

    Tiemersma, E.W.; Omer, R.E.; Bunschoten, A.; van't Veer, P.; Kok, F.J.; Idrsi, M.O.; Kampman, E.

    2001-01-01

    Exposure to aflatoxins is a risk factor for hepatocellular carcinoma (HCC). Aflatoxins occur in peanut butter and are metabolized by genetically polymorphic enzymes such as glutathione-S-transferases encoded by glutathione-S-transferase mu 1 gene (GSTM1) and glutathione-S-transferase theta 1 gene (G

  6. Oral Cancer Exam

    Medline Plus

    Full Text Available ... for signs of oral cancer. For Patients and the Public Oral Cancer Pamphlet that describes the risk factors, signs and symptoms of oral cancer, and the importance of detecting the disease in its early ...

  7. Oral Cancer Exam

    Medline Plus

    Full Text Available ... Programs Careers in Dental Research See All Continuing Education Practical Oral Care for People With Developmental Disabilities – ... detection and treatment of oral cancers. Note: For materials specific to African American men, please see: Oral ...

  8. Oral Lichen Planus

    Science.gov (United States)

    Oral lichen planus Overview By Mayo Clinic Staff Oral lichen planus (LIE-kun PLAY-nus) is an ongoing (chronic) ... that affects mucous membranes inside your mouth. Oral lichen planus may appear as white, lacy patches; red, ...

  9. Oral Health Glossary

    Science.gov (United States)

    ... About | Contact InfoBites Quick Reference Learn more Children's Oral Health Mouth Breathing Can Cause Major Health Problems Over ... news feeds delivered directly to your desktop! more... Oral Health Glossary Article Chapters Oral Health Glossary print full ...

  10. Oral Cancer Exam

    Medline Plus

    Full Text Available ... for signs of oral cancer. For Patients and the Public Oral Cancer Pamphlet that describes the risk factors, signs and symptoms of oral cancer, and the importance of detecting the disease in its early ...

  11. GalNAc-transferase specificity prediction based on feature selection method.

    Science.gov (United States)

    Lu, Lin; Niu, Bing; Zhao, Jun; Liu, Liang; Lu, Wen-Cong; Liu, Xiao-Jun; Li, Yi-Xue; Cai, Yu-Dong

    2009-02-01

    GalNAc-transferase can catalyze the biosynthesis of O-linked oligosaccharides. The specificity of GalNAc-transferase is composed of nine amino acid residues denoted by R4, R3, R2, R1, R0, R1', R2', R3', R4'. To predict whether the reducing monosaccharide will be covalently linked to the central residue R0(Ser or Thr), a new method based on feature selection has been proposed in our work. 277 nonapeptides from reference [Chou KC. A sequence-coupled vector-projection model for predicting the specificity of GalNAc-transferase. Protein Sci 1995;4:1365-83] are chosen for training set. Each nonapeptide is represented by hundreds of amino acid properties collected by Amino Acid Index database (http://www.genome.jp/aaindex) and transformed into a numeric vector with 4554 features. The Maximum Relevance Minimum Redundancy (mRMR) method combining with Incremental Feature Selection (IFS) and Feature Forward Selection (FFS) are then applied for feature selection. Nearest Neighbor Algorithm (NNA) is used to build prediction models. The optimal model contains 54 features and its correct rate tested by Jackknife cross-validation test reaches 91.34%. Final feature analysis indicates that amino acid residues at position R3' play the most important role in the recognition of GalNAc-transferase specificity, which were confirmed by the experiments [Elhammer AP, Poorman RA, Brown E, Maggiora LL, Hoogerheide JG, Kezdy FJ. The specificity of UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase as inferred from a database of in vivo substrates and from the in vitro glycosylation of proteins and peptides. J Biol Chem 1993;268:10029-38; O'Connell BC, Hagen FK, Tabak LA. The influence of flanking sequence on the O-glycosylation of threonine in vitro. J Biol Chem 1992;267:25010-8; Yoshida A, Suzuki M, Ikenaga H, Takeuchi M. Discovery of the shortest sequence motif for high level mucin-type O-glycosylation. J Biol Chem 1997;272:16884-8]. Our method can be used as a tool for predicting O

  12. UDP-N-acetyl-alpha-D-galactosamine:polypeptide N-acetylgalactosaminyltransferase. Identification and separation of two distinct transferase activities

    DEFF Research Database (Denmark)

    Sørensen, T; White, T; Wandall, H H;

    1995-01-01

    Using a defined acceptor substrate peptide as an affinity chromatography ligand we have developed a purification scheme for a unique human polypeptide, UDP-GalNAc:polypeptide N-acetylgalactosaminyltransferase (GalNAc-transferase) (White, T., Bennett, E.P., Takio, K., Sørensen, T., Bonding, N......., and Clausen, H. (1995) J. Biol. Chem. 270, 24156-24165). Here we report detailed studies of the acceptor substrate specificity of GalNAc-transferase purified by this scheme as well as the Gal-NAc-transferase activity, which, upon repeated affinity chromatography, evaded purification by this affinity ligand...

  13. MODE OF ACTION OF LANTANA CAMARA EXTRACTS ON ENZYMES ASPARTATE AMINO TRANSFERASE AND ALANINE AMINO TRANSFERASE ACTIVITY IN TARGET AND NONTARGET ORGANISMS

    Directory of Open Access Journals (Sweden)

    DIVYA RAJAN

    2013-01-01

    Full Text Available The plant Lantana camara on the basis of study conducted found to show effective larvicidal activity. The presentstudy deals with the mode of action of Lantana camara extract on enzymes, Aspartate Amino Transferase andAlanine Amino Transferase activity in target and non-target organisms. The major transaminase system of the bodysuch as AsAT and AlAT were significantly inhibited by the plant extract. A significant decrease in the activity ofabove two enzyme systems were observed from the fourth h of incubation onwards. The transaminase system ofmosquito larvae was more sensitive to Lantana camara extract than that of vertebrate system such as Anabastestudineus and Rana hexadactyla which are the non-target organisms seen in the aquatic habitat. The majortransaminase systems of the body such as AsAT and AlAT were inhibited in a dose dependent manner under bothinvitro and invivo conditions. The change of pH from alkaline (normal larvae to acidic (intoxicated larvae, mayalso be sufficient for inhibiting or blocking most of the enzymatic reactions leading to the death of the organisms.The results of this experiment indicated that the shrub Lantana camara could be studied further in detail and itsbenificial effects to the control of vector bron diseases could be utilised for healthy environments

  14. Lectin Domains of Polypeptide GalNAc Transferases Exhibit Glycopeptide Binding Specificity

    DEFF Research Database (Denmark)

    Pedersen, Johannes W; Bennett, Eric P; Schjoldager, Katrine T-B G;

    2011-01-01

    UDP-GalNAc:polypeptide a-N-acetylgalactosaminyltransferases (GalNAc-Ts) constitute a family of up to 20 transferases that initiate mucin-type O-glycosylation. The transferases are structurally composed of catalytic and lectin domains. Two modes have been identified for the selection...... of glycosylation sites by GalNAc-Ts: confined sequence recognition by the catalytic domain alone, and concerted recognition of acceptor sites and adjacent GalNAc-glycosylated sites by the catalytic and lectin domains, respectively. Thus far, only the catalytic domain has been shown to have peptide sequence...... on sequences of mucins MUC1, MUC2, MUC4, MUC5AC, MUC6, and MUC7 as well as a random glycopeptide bead library, we examined the binding properties of four different lectin domains. The lectin domains of GalNAc-T1, -T2, -T3, and -T4 bound different subsets of small glycopeptides. These results indicate...

  15. Design and synthesis of potent inhibitors of the mono(ADP-ribosyl)transferase, PARP14.

    Science.gov (United States)

    Upton, Kristen; Meyers, Matthew; Thorsell, Ann-Gerd; Karlberg, Tobias; Holechek, Jacob; Lease, Robert; Schey, Garrett; Wolf, Emily; Lucente, Adrianna; Schüler, Herwig; Ferraris, Dana

    2017-07-01

    A series of (Z)-4-(3-carbamoylphenylamino)-4-oxobut-2-enyl amides were synthesized and tested for their ability to inhibit the mono-(ADP-ribosyl)transferase, PARP14 (a.k.a. BAL-2; ARTD-8). Two synthetic routes were established for this series and several compounds were identified as sub-micromolar inhibitors of PARP14, the most potent of which was compound 4t, IC50=160nM. Furthermore, profiling other members of this series identified compounds with >20-fold selectivity over PARP5a/TNKS1, and modest selectivity over PARP10, a closely related mono-(ADP-ribosyl)transferase. Copyright © 2017 Elsevier Ltd. All rights reserved.

  16. Three-dimensional structure of a Bombyx mori Omega-class glutathione transferase.

    Science.gov (United States)

    Yamamoto, Kohji; Suzuki, Mamoru; Higashiura, Akifumi; Nakagawa, Atsushi

    2013-09-01

    Glutathione transferases (GSTs) are major phase II detoxification enzymes that play central roles in the defense against various environmental toxicants as well as oxidative stress. Here we report the crystal structure of an Omega-class glutathione transferase of Bombyx mori, bmGSTO, to gain insight into its catalytic mechanism. The structure of bmGSTO complexed with glutathione determined at a resolution of 2.5Å reveals that it exists as a dimer and is structurally similar to Omega-class GSTs with respect to its secondary and tertiary structures. Analysis of a complex between bmGSTO and glutathione showed that bound glutathione was localized to the glutathione-binding site (G-site). Site-directed mutagenesis of bmGSTO mutants indicated that amino acid residues Leu62, Lys65, Lys77, Val78, Glu91 and Ser92 in the G-site contribute to catalytic activity.

  17. Structural characterization of the catalytic site of a Nilaparvata lugens delta-class glutathione transferase.

    Science.gov (United States)

    Yamamoto, Kohji; Higashiura, Akifumi; Hossain, Md Tofazzal; Yamada, Naotaka; Shiotsuki, Takahiro; Nakagawa, Atsushi

    2015-01-15

    Glutathione transferases (GSTs) are a major class of detoxification enzymes that play a central role in the defense against environmental toxicants and oxidative stress. Here, we studied the crystal structure of a delta-class glutathione transferase from Nilaparvata lugens, nlGSTD, to gain insights into its catalytic mechanism. The structure of nlGSTD in complex with glutathione, determined at a resolution of 1.7Å, revealed that it exists as a dimer and its secondary and tertiary structures are similar to those of other delta-class GSTs. Analysis of a complex between nlGSTD and glutathione showed that the bound glutathione was localized to the glutathione-binding site. Site-directed mutagenesis of nlGSTD mutants indicated that amino acid residues Ser11, His52, Glu66, and Phe119 contribute to catalytic activity.

  18. Isolation and characterization of Phi class glutathione transferase partial gene from Iranian barley

    Directory of Open Access Journals (Sweden)

    Hassan Mohabatkar

    2012-01-01

    Full Text Available Glutathione transferases are multifunctional proteins involved in several diverse intracellular events such as primary and secondary metabolisms, signaling and stress metabolism. These enzymes have been subdivided into eight classes in plants. The Phi class, being plant specific, is the most represented. In the present study, based on the sequences available at GenBank, different primers were designed for amplifying the Phi class of glutathione transferase gene in the genome and transcriptome of Iranian barley, Karoun cultivar. After extraction of DNA and total RNA, Phi class was amplified and sequenced. Bioinformatics analysis predicted that the deduced protein sequence has two ß-sheets, eight α-helices and some intermediate loops in its secondary structure. Consequently, the sequences were submitted to NCBI GenBank with GS262333 and GW342614 accession numbers. Phylogenic relationships of the sequences were compared with existing sequences in GenBank.

  19. Structural insight into the active site of a Bombyx mori unclassified glutathione transferase.

    Science.gov (United States)

    Hossain, Md Tofazzal; Yamamoto, Kohji

    2015-01-01

    Glutathione transferases (GSTs) are major detoxification enzymes that play central roles in the defense against various environmental toxicants as well as oxidative stress. Here, we identify amino acid residues of an unclassified GST from Bombyx mori, bmGSTu-interacting glutathione (GSH). Site-directed mutagenesis of bmGSTu mutants indicated that amino acid residues Asp103, Ser162, and Ser166 contribute to catalytic activity.

  20. Nourseothricin N-acetyl transferase: a positive selection marker for mammalian cells.

    Directory of Open Access Journals (Sweden)

    Bose S Kochupurakkal

    Full Text Available Development of Nourseothricin N-acetyl transferase (NAT as a selection marker for mammalian cells is described. Mammalian cells are acutely susceptible to Nourseothricin, similar to the widely used drug Puromycin, and NAT allows for quick and robust selection of transfected/transduced cells in the presence of Nourseothricin. NAT is compatible with other selection markers puromycin, hygromycin, neomycin, blasticidin, and is a valuable addition to the repertoire of mammalian selection markers.

  1. Summarize of Glutathione S-transferases%谷胱甘肽S-转移酶综述

    Institute of Scientific and Technical Information of China (English)

    张飚; 李永清; 高轩

    2006-01-01

    谷胱甘肽S-转移酶(glutathioneS-transferases,GSTs)是由多个基因编码、具有多种功能的超基因家族酶,是多种生物体内的主要解毒系统.本文综述了GSTs的分型、结构等方面的研究进展.

  2. Human liver morphine UDP-glucuronyl transferase enantioselectivity and inhibition by opioid congeners and oxazepam.

    OpenAIRE

    Wahlström, A; Pacifici, G. M.; Lindström, B; Hammar, L.; Rane, A.

    1988-01-01

    1. Morphine uridine diphosphate glucuronyl transferase (UDP-GT) was studied in human liver microsomes. The (-)- and (+)-morphine enantiomers were used as substrates and inhibitors, such as oxazepam and various opioid congeners were employed to characterize the different glucuronidation pathways. The kinetics of the oxazepam inhibition were studied in the rat liver. 2. The overall glucuronidation of (+)-morphine was higher than that of (-)-morphine. The morphine congeners tested, potently inhi...

  3. Correlation Between Iron and alpha and pi Glutathione-S-Transferase Levels in Humans

    Science.gov (United States)

    2012-09-01

    including duodenal crypt cells and macrophages . Several well characterized mutations in this gene have been shown to increase iron levels.16 Of...genotoxic products of lipid peroxication. (1998) Biochem. J. 330:174-179. 4Townsend DM, Tew KD. “The role of glutathione-S-transferase in anti- cancer ...and ferritin.” Semin Hematol. (1998) 35:35-54. 12Iancu TC. “ Ultrastructural aspects of iron storage, transport, and metabolism.” J Neural Transm

  4. Role of glutathione, glutathione transferase, and glutaredoxin in regulation of redox-dependent processes.

    Science.gov (United States)

    Kalinina, E V; Chernov, N N; Novichkova, M D

    2014-12-01

    Over the last decade fundamentally new features have been revealed for the participation of glutathione and glutathione-dependent enzymes (glutathione transferase and glutaredoxin) in cell proliferation, apoptosis, protein folding, and cell signaling. Reduced glutathione (GSH) plays an important role in maintaining cellular redox status by participating in thiol-disulfide exchange, which regulates a number of cell functions including gene expression and the activity of individual enzymes and enzyme systems. Maintaining optimum GSH/GSSG ratio is essential to cell viability. Decrease in the ratio can serve as an indicator of damage to the cell redox status and of changes in redox-dependent gene regulation. Disturbance of intracellular GSH balance is observed in a number of pathologies including cancer. Consequences of inappropriate GSH/GSSG ratio include significant changes in the mechanism of cellular redox-dependent signaling controlled both nonenzymatically and enzymatically with the participation of isoforms of glutathione transferase and glutaredoxin. This review summarizes recent data on the role of glutathione, glutathione transferase, and glutaredoxin in the regulation of cellular redox-dependent processes.

  5. Characterization of Affinity-Purified Isoforms of Acinetobacter calcoaceticus Y1 Glutathione Transferases

    Directory of Open Access Journals (Sweden)

    Chin-Soon Chee

    2014-01-01

    Full Text Available Glutathione transferases (GST were purified from locally isolated bacteria, Acinetobacter calcoaceticus Y1, by glutathione-affinity chromatography and anion exchange, and their substrate specificities were investigated. SDS-polyacrylamide gel electrophoresis revealed that the purified GST resolved into a single band with a molecular weight (MW of 23 kDa. 2-dimensional (2-D gel electrophoresis showed the presence of two isoforms, GST1 (pI 4.5 and GST2 (pI 6.2 with identical MW. GST1 was reactive towards ethacrynic acid, hydrogen peroxide, 1-chloro-2,4-dinitrobenzene, and trans,trans-hepta-2,4-dienal while GST2 was active towards all substrates except hydrogen peroxide. This demonstrated that GST1 possessed peroxidase activity which was absent in GST2. This study also showed that only GST2 was able to conjugate GSH to isoproturon, a herbicide. GST1 and GST2 were suggested to be similar to F0KLY9 (putative glutathione S-transferase and F0KKB0 (glutathione S-transferase III of Acinetobacter calcoaceticus strain PHEA-2, respectively.

  6. Characterization of affinity-purified isoforms of Acinetobacter calcoaceticus Y1 glutathione transferases.

    Science.gov (United States)

    Chee, Chin-Soon; Tan, Irene Kit-Ping; Alias, Zazali

    2014-01-01

    Glutathione transferases (GST) were purified from locally isolated bacteria, Acinetobacter calcoaceticus Y1, by glutathione-affinity chromatography and anion exchange, and their substrate specificities were investigated. SDS-polyacrylamide gel electrophoresis revealed that the purified GST resolved into a single band with a molecular weight (MW) of 23 kDa. 2-dimensional (2-D) gel electrophoresis showed the presence of two isoforms, GST1 (pI 4.5) and GST2 (pI 6.2) with identical MW. GST1 was reactive towards ethacrynic acid, hydrogen peroxide, 1-chloro-2,4-dinitrobenzene, and trans,trans-hepta-2,4-dienal while GST2 was active towards all substrates except hydrogen peroxide. This demonstrated that GST1 possessed peroxidase activity which was absent in GST2. This study also showed that only GST2 was able to conjugate GSH to isoproturon, a herbicide. GST1 and GST2 were suggested to be similar to F0KLY9 (putative glutathione S-transferase) and F0KKB0 (glutathione S-transferase III) of Acinetobacter calcoaceticus strain PHEA-2, respectively.

  7. Structural evidence for conformational changes of Delta class glutathione transferases after ligand binding.

    Science.gov (United States)

    Wongsantichon, Jantana; Robinson, Robert C; Ketterman, Albert J

    2012-05-01

    We report four new crystal structures for Delta class glutathione transferases from insects. We compare these new structures as well as several previously reported structures to determine that structural transitions can be observed with ligand binding. These transitions occurred in the regions around the active site entrance, including alpha helix 2, C-terminus of alpha helix 4 including the loop to helix 5 and the C-terminus of helix 8. These structural movements have been reported or postulated to occur for several other glutathione transferase classes; however, this is the first report showing structural evidence of all these movements occurring, in this case in Delta class glutathione transferases. These fluctuations also can be observed occurring within a single structure as there is ligand bound in only one subunit and each subunit is undergoing different conformational transitions. The structural comparisons show reorganizations occur both pre- and post-GSH ligand binding communicated through the subunit interface of the quaternary assembly. Movements of these positions would allow 'breathing' of the active site for substrate entrance, topological rearrangement for varying substrate specificity and final product release.

  8. Euphorbia characias latex: micromorphology of rubber particles and rubber transferase activity.

    Science.gov (United States)

    Spanò, Delia; Pintus, Francesca; Esposito, Francesca; Loche, Danilo; Floris, Giovanni; Medda, Rosaria

    2015-02-01

    We have recently characterized a natural rubber in the latex of Euphorbia characias. Following that study, we here investigated the rubber particles and rubber transferase in that Mediterranean shrub. Rubber particles, observed by scanning electron microscopy, are spherical in shape with diameter ranging from 0.02 to 1.2 μm. Washed rubber particles exhibit rubber transferase activity with a rate of radiolabeled [(14)C]IPP incorporation of 4.5 pmol min(-1)mg(-1). Denaturing electrophoresis profile of washed rubber particles reveals a single protein band of 37 kDa that is recognized in western blot analysis by antibodies raised against the synthetic peptide whose sequence, DVVIRTSGETRLSNF, is included in one of the five regions conserved among cis-prenyl chain elongation enzymes. The cDNA nucleotide sequence of E. characias rubber transferase (GenBank JX564541) and the deduced amino acid sequence appear to be highly homologous to the sequence of several plant cis-prenyltransferases.

  9. Inhibition of the ribosomal peptidyl transferase reaction by the mycarose moiety of the antibiotics carbomycin, spiramycin and tylosin

    DEFF Research Database (Denmark)

    Poulsen, S M; Kofoed, C; Vester, B

    2000-01-01

    Many antibiotics, including the macrolides, inhibit protein synthesis by binding to ribosomes. Only some of the macrolides affect the peptidyl transferase reaction. The 16-member ring macrolide antibiotics carbomycin, spiramycin, and tylosin inhibit peptidyl transferase. All these have a disaccha......Many antibiotics, including the macrolides, inhibit protein synthesis by binding to ribosomes. Only some of the macrolides affect the peptidyl transferase reaction. The 16-member ring macrolide antibiotics carbomycin, spiramycin, and tylosin inhibit peptidyl transferase. All these have...... with hairpin 35 in domain II. Competitive footprinting of ribosomal binding of hygromycin A and macrolides showed that tylosin and spiramycin reduce the hygromycin A protections of nucleotides in 23 S rRNA and that carbomycin abolishes its binding. In contrast, the macrolides that do not inhibit the peptidyl...

  10. RPR 107393, a potent squalene synthase inhibitor and orally effective cholesterol-lowering agent: comparison with inhibitors of HMG-CoA reductase.

    Science.gov (United States)

    Amin, D; Rutledge, R Z; Needle, S N; Galczenski, H F; Neuenschwander, K; Scotese, A C; Maguire, M P; Bush, R C; Hele, D J; Bilder, G E; Perrone, M H

    1997-05-01

    Squalene synthase catalyzes the reductive dimerization of two molecules of farnesyl pyrophosphate to form squalene and is the first committed step in sterol synthesis. A specific inhibitor of squalene synthase would inhibit cholesterol biosynthesis but not prevent the formation of other products of the isoprenoid pathway, such as dolichol and ubiquinone. RPR 107393 [3-hydroxy-3-[4-(quinolin-6-yl)phenyl]-1-azabicyclo[2-2-2]octane dihydrochloride] and its R and S enantiomers are potent inhibitors of rat liver microsomal squalene synthase, with IC50 values of 0.6 to 0.9 nM. One hour after oral administration to rats, RPR 107393 inhibited de novo [14C]cholesterol biosynthesis from [14C]mevalonate in the liver with an ED50 value of 5 mg/kg. Diacid metabolites of [14C]farnesyl pyrophosphate were identified after acid treatment of the livers of these animals. These results support in vitro data demonstrating that these compounds are inhibitors of squalene synthase. In rats, RPR 107393 (30 mg/kg p.o. b.i.d. for 2 days) reduced total serum cholesterol by RPR 107393 (20 mg/kg b.i.d.) reduced plasma cholesterol concentration by 50% after 1 week of administration; this was greater than the reduction observed with lovastatin or pravastatin, neither of which produced > 31% reduction in plasma cholesterol when administered for 1 week at a dose of 50 mg/kg b.i.d. The R and S enantiomers of RPR 107393 (20 mg/kg p.o. q.d. for 7 days) reduced plasma low density lipoprotein cholesterol by 50% and 43%, respectively, whereas high density lipoprotein cholesterol was unchanged. In summary, RPR 107393 is a potent inhibitor of squalene synthase. It is an orally effective hypocholesterolemic agent in rats and marmosets that has greater efficacy than lovastatin or pravastatin in the marmoset.

  11. Ternary complex structures of human farnesyl pyrophosphate synthase bound with a novel inhibitor and secondary ligands provide insights into the molecular details of the enzyme’s active site closure

    Directory of Open Access Journals (Sweden)

    Park Jaeok

    2012-12-01

    Full Text Available Abstract Background Human farnesyl pyrophosphate synthase (FPPS controls intracellular levels of farnesyl pyrophosphate, which is essential for various biological processes. Bisphosphonate inhibitors of human FPPS are valuable therapeutics for the treatment of bone-resorption disorders and have also demonstrated efficacy in multiple tumor types. Inhibition of human FPPS by bisphosphonates in vivo is thought to involve closing of the enzyme’s C-terminal tail induced by the binding of the second substrate isopentenyl pyrophosphate (IPP. This conformational change, which occurs through a yet unclear mechanism, seals off the enzyme’s active site from the solvent environment and is essential for catalysis. The crystal structure of human FPPS in complex with a novel bisphosphonate YS0470 and in the absence of a second substrate showed partial ordering of the tail in the closed conformation. Results We have determined crystal structures of human FPPS in ternary complex with YS0470 and the secondary ligands inorganic phosphate (Pi, inorganic pyrophosphate (PPi, and IPP. Binding of PPi or IPP to the enzyme-inhibitor complex, but not that of Pi, resulted in full ordering of the C-terminal tail, which is most notably characterized by the anchoring of the R351 side chain to the main frame of the enzyme. Isothermal titration calorimetry experiments demonstrated that PPi binds more tightly to the enzyme-inhibitor complex than IPP, and differential scanning fluorometry experiments confirmed that Pi binding does not induce the tail ordering. Structure analysis identified a cascade of conformational changes required for the C-terminal tail rigidification involving Y349, F238, and Q242. The residues K57 and N59 upon PPi/IPP binding undergo subtler conformational changes, which may initiate this cascade. Conclusions In human FPPS, Y349 functions as a safety switch that prevents any futile C-terminal closure and is locked in the “off” position in the

  12. Glutathione transferase from Trichoderma virens enhances cadmium tolerance without enhancing its accumulation in transgenic Nicotiana tabacum.

    Directory of Open Access Journals (Sweden)

    Prachy Dixit

    Full Text Available BACKGROUND: Cadmium (Cd is a major heavy metal pollutant which is highly toxic to plants and animals. Vast agricultural areas worldwide are contaminated with Cd. Plants take up Cd and through the food chain it reaches humans and causes toxicity. It is ideal to develop plants tolerant to Cd, without enhanced accumulation in the edible parts for human consumption. Glutathione transferases (GST are a family of multifunctional enzymes known to have important roles in combating oxidative stresses induced by various heavy metals including Cd. Some GSTs are also known to function as glutathione peroxidases. Overexpression/heterologous expression of GSTs is expected to result in plants tolerant to heavy metals such as Cd. RESULTS: Here, we report cloning of a glutathione transferase gene from Trichoderma virens, a biocontrol fungus and introducing it into Nicotiana tabacum plants by Agrobacterium-mediated gene transfer. Transgenic nature of the plants was confirmed by Southern blot hybridization and expression by reverse transcription PCR. Transgene (TvGST showed single gene Mendelian inheritance. When transgenic plants expressing TvGST gene were exposed to different concentrations of Cd, they were found to be more tolerant compared to wild type plants, with transgenic plants showing lower levels of lipid peroxidation. Levels of different antioxidant enzymes such as glutathione transferase, superoxide dismutase, ascorbate peroxidase, guiacol peroxidase and catalase showed enhanced levels in transgenic plants expressing TvGST compared to control plants, when exposed to Cd. Cadmium accumulation in the plant biomass in transgenic plants were similar or lower than wild-type plants. CONCLUSION: The results of the present study suggest that transgenic tobacco plants expressing a Trichoderma virens GST are more tolerant to Cd, without enhancing its accumulation in the plant biomass. It should be possible to extend the present results to crop plants for

  13. Inherited glutathione-S-transferase deficiency is a risk factor for pulmonary asbestosis.

    Science.gov (United States)

    Smith, C M; Kelsey, K T; Wiencke, J K; Leyden, K; Levin, S; Christiani, D C

    1994-09-01

    Pulmonary diseases attributable to asbestos exposure constitute a significant public health burden, yet few studies have investigated potential genetic determinants of susceptibility to asbestos-related diseases. The glutathione-S-transferases are a family of conjugating enzymes that both catalyze the detoxification of a variety of potentially cytotoxic electrophilic agents and act in the generation of sulfadipeptide leukotriene inflammatory mediators. The gene encoding glutathione-S-transferase class mu (GSTM-1) is polymorphic; approximately 50% of Caucasian individuals have a homozygous deletion of this gene and do not produce functional enzyme. Glutathione-S-transferase mu (GST-mu) deficiency has been previously reported to be associated with smoking-induced lung cancer. We conducted a cross-sectional study to examine the prevalence of the homozygous deletion for the GSTM-1 gene in members of the carpentry trade occupationally exposed to asbestos. Members of the United Brotherhood of Carpenters and Joiners of America attending their 1991 National Union conference were invited to participate. Each participant was offered a chest X-ray and was asked to complete a comprehensive questionnaire and have their blood drawn. All radiographs were assessed for the presence of pneumoconiosis in a blinded fashion by a National Institute for Occupational Safety and Health-certified International Labor Office "B" reader. Individual GSTM-1 status was determined using polymerase chain reaction methods. Six hundred fifty-eight workers were studied. Of these, 80 (12.2%) had X-ray abnormalities associated with asbestos exposure. Individuals genetically deficient in GST-mu were significantly more likely to have radiographic evidence of nonmalignant asbestos-related disease than those who were not deficient (chi 2 = 5.0; P < 0.03).(ABSTRACT TRUNCATED AT 250 WORDS)

  14. Oral Cancer Exam

    Medline Plus

    Full Text Available ... and Deadlines Grant Application Forms Application Receipt Dates Electronic Submission of Applications Grants 101 (How to Write ... detection and treatment of oral cancers. Note: For materials specific to African American men, please see: Oral ...

  15. Oral Appliances Therapy

    Science.gov (United States)

    ... your sleep doctor may schedule you for a sleep study to verify treatment success. Follow-Up Visits Follow-up visits with your dentist will be needed to ensure the optimal fit of the oral appliance. Effective oral appliances ...

  16. Oral Cancer Exam

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    Full Text Available ... See All Oral Complications of Systemic Diseases Cancer Treatment Developmental Disabilities Diabetes Heart Disease HIV/AIDS See ... this brochure includes information on symptoms, diagnosis, and treatment of oral cancer, along with definitions of selected ...

  17. Oral Cancer Exam

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    Full Text Available ... the exam can detect oral cancer early—when it can be treated more successfully. Publications​ For Health ... and the importance of detecting the disease in its early stages. The Oral Cancer Exam Step-by- ...

  18. Oral Cancer Exam

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    Full Text Available ... Oral Complications of Systemic Diseases Cancer Treatment Developmental Disabilities Diabetes Heart Disease HIV/AIDS See All Order ... Education Practical Oral Care for People With Developmental Disabilities – This booklet presents an overview of physical, mental, ...

  19. Oral Cancer Exam

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    Full Text Available ... signs of oral cancer. For Patients and the Public Oral Cancer Pamphlet that describes the risk factors, ... not collect any actual information. External Web Site Policy This graphic notice ( ) means that you are leaving ...

  20. Oral Cancer Exam

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    Full Text Available ... diagnosis, and treatment of oral cancer, along with definitions of selected medical terms and resource information. Oral ... of Dental and Craniofacial Research National Institutes of Health Bethesda, MD 20892-2190 301-496-4261 NIH… ...

  1. Oral Cancer Exam

    Medline Plus

    Full Text Available ... See All Oral Complications of Systemic Diseases Cancer Treatment Developmental Disabilities Diabetes Heart Disease HIV/AIDS See ... this brochure includes information on symptoms, diagnosis, and treatment of oral cancer, along with definitions of selected ...

  2. Oral Cancer Exam

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    Full Text Available ... and College Students Recent College Graduates Dental and Medical Students See All Careers & Training Opportunities Job Openings ... of oral cancer, along with definitions of selected medical terms and resource information. Oral Cancer A fact ...

  3. Oral Cancer Exam

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    Full Text Available ... signs of oral cancer. For Patients and the Public Oral Cancer Pamphlet that ... any actual information. External Web Site Policy This graphic notice ( ) means that you are leaving ...

  4. Oral Cancer Exam

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    Full Text Available ... the exam can detect oral cancer early—when it can be treated more successfully. Publications​ For Health ... and the importance of detecting the disease in its early stages. The Oral Cancer Exam Step-by- ...

  5. Differential roles of tau class glutathione S-transferases in oxidative stress

    DEFF Research Database (Denmark)

    Kilili, Kimiti G; Atanassova, Neli; Vardanyan, Alla

    2004-01-01

    The plant glutathione S-transferase BI-GST has been identified as a potent inhibitor of Bax lethality in yeast, a phenotype associated with oxidative stress and disruption of mitochondrial functions. Screening of a tomato two-hybrid library for BI-GST interacting proteins identified five homologous...... Tau class GSTs, which readily form heterodimers between them and BI-GST. All six LeGSTUs were found to be able to protect yeast cells from prooxidant-induced cell death. The efficiency of each LeGSTU was prooxidant-specific, indicating a different role for each LeGSTU in the oxidative stress...

  6. Glutathione-binding site of a bombyx mori theta-class glutathione transferase.

    Science.gov (United States)

    Hossain, M D Tofazzal; Yamada, Naotaka; Yamamoto, Kohji

    2014-01-01

    The glutathione transferase (GST) superfamily plays key roles in the detoxification of various xenobiotics. Here, we report the isolation and characterization of a silkworm protein belonging to a previously reported theta-class GST family. The enzyme (bmGSTT) catalyzes the reaction of glutathione with 1-chloro-2,4-dinitrobenzene, 1,2-epoxy-3-(4-nitrophenoxy)-propane, and 4-nitrophenethyl bromide. Mutagenesis of highly conserved residues in the catalytic site revealed that Glu66 and Ser67 are important for enzymatic function. These results provide insights into the catalysis of glutathione conjugation in silkworm by bmGSTT and into the metabolism of exogenous chemical agents.

  7. Functional Diversification of Fungal Glutathione Transferases from the Ure2p Class

    OpenAIRE

    Anne Thuillier; Ngadin, Andrew A.; Cécile Thion; Patrick Billard; Jean-Pierre Jacquot; Eric Gelhaye; Mélanie Morel

    2011-01-01

    The glutathione-S-transferase (GST) proteins represent an extended family involved in detoxification processes. They are divided into various classes with high diversity in various organisms. The Ure2p class is especially expanded in saprophytic fungi compared to other fungi. This class is subdivided into two subclasses named Ure2pA and Ure2pB, which have rapidly diversified among fungal phyla. We have focused our analysis on Basidiomycetes and used Phanerochaete chrysosporium as a model to c...

  8. Glutathione transferases as mediators of signaling pathways involved in cell proliferation and cell death.

    Science.gov (United States)

    Laborde, E

    2010-09-01

    Glutathione transferases (GSTs) are enzymes that catalyze the conjugation of glutathione (GSH) to a variety of electrophilic substances. Their best known role is as cell housekeepers engaged in the detoxification of xenobiotics. Recently, GSTs have also been shown to act as modulators of signal transduction pathways that control cell proliferation and cell death. Their involvement in cancer cell growth and differentiation, and in the development of resistance to anticancer agents, has made them attractive drug targets. This review is focused on the inhibition of GSTs, in particular GSTP1-1, as a potential therapeutic approach for the treatment of cancer and other diseases associated with aberrant cell proliferation.

  9. Puromycin-rRNA interaction sites at the peptidyl transferase center

    DEFF Research Database (Denmark)

    Rodriguez-Fonseca, Christina; Phan, Hien; Long, Katherine Sarah

    2000-01-01

    The binding site of puromycin was probed chemically in the peptidyl-transferase center of ribosomes from Escherichia coli and of puromycin-hypersensitive ribosomes from the archaeon Haloferax gibbonsii. Several nucleotides of the 23S rRNAs showed altered chemical reactivities in the presence....... This streptogramin motif is also likely to provide binding sites for the 3' termini of the acceptor and donor tRNAs. In contrast, the effects at A508 and A1579, which are located at the exit site of the peptide channel, are likely to be caused by a structural effect transmitted along the peptide channel....

  10. Mechanism of activation of mouse liver microsomal glutations S—transferase by paracetamol treatment

    Institute of Scientific and Technical Information of China (English)

    ZhenY; LouYJ

    2002-01-01

    Microsomal glutathion S-transferase(mGST) is one of the important detoxifcation enzymes in vivo,its modifying activation by drugs has been paid more attention to in pertinent field recently.This study was to explore the influence of paracetamol(Par) on mGST and its possible mechanism in vivo,and to further reveal the biological significance.Par is metabolized to N-acetyl-p-benzoquinone imine(NAPQI) by CYP2E1 and mGST is activated by sulfhydryl modification.

  11. Micronuclei rate and hypoxanthine phosphoribosyl transferase mutation in radon-exposed rats

    Institute of Scientific and Technical Information of China (English)

    Fengmei Cui; Saijun Fan; Mingjiang Hu; Jihua Nie; Hongmei Li; Jian Tong

    2008-01-01

    The genetic changes in rats with radon exposure were studied by the micronucleus technology and detection of hypoxanthine phosphoribosyl transferase (hprt) mutations.The rate of the micronuclei in peripheral blood lymphocytes and tracheal-bronchial epithelial cells in the radon-inhaled rats was higher than that of the controls (P < 0.05).A similar result was obtained from the hprt assay,which showed a higher mutation frequency in radon-exposed rats.Our results suggested that micronuclei rate and hprt deficiency could be used as biomarkers for the genetic changes with radon exposure.

  12. A novel plant glutathione S-transferase/peroxidase suppresses Bax lethality in yeast

    DEFF Research Database (Denmark)

    Kampranis, S C; Damianova, R; Atallah, M

    2000-01-01

    for the identification of plant genes, which inhibit either directly or indirectly the lethal phenotype of Bax. Using this method a number of cDNA clones were isolated, the more potent of which encodes a protein homologous to the class theta glutathione S-transferases. This Bax-inhibiting (BI) protein was expressed......The mammalian inducer of apoptosis Bax is lethal when expressed in yeast and plant cells. To identify potential inhibitors of Bax in plants we transformed yeast cells expressing Bax with a tomato cDNA library and we selected for cells surviving after the induction of Bax. This genetic screen allows...

  13. HAD Oral History Project

    Science.gov (United States)

    Holbrook, Jarita

    2014-01-01

    The Historical Astronomy Division is the recipient of an American Institute of Physics Neils Bohr Library Grant for Oral History. HAD has assembled a team of volunteers to conduct oral history interviews since May 2013. Each oral history interview varies in length between two and six hours. This presentation is an introduction to the HAD Oral History Project and the activities of the team during the first six months of the grant.

  14. Oral Steroids for Dermatitis.

    Science.gov (United States)

    Fisher, Andrew D; Clarke, Jesse; Williams, Timothy K

    2015-01-01

    Contact/allergic dermatitis is frequently treated inappropriately with lower-than-recommended doses or inadequate duration of treatment with oral and intramuscular glucocorticoids. This article highlights a case of dermatitis in a Ranger Assessment and Selection Program student who was improperly treated over 2 weeks with oral steroids after being bit by Cimex lectularius, commonly known as bed bugs. The article also highlights the pitfalls of improper oral steroid dosing and provides reasoning for longer-duration oral steroid treatment.

  15. Oral Cancer Exam

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    Full Text Available ... Contents NIDCR Home Oral Health Diseases and Conditions Gum Disease TMJ Disorders Oral Cancer Dry Mouth Burning Mouth Tooth Decay See All Oral Complications of Systemic Diseases Cancer Treatment Developmental Disabilities Diabetes Heart Disease HIV/AIDS See All Order Publications ...

  16. Oral Health and Aging

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    ... of this page please turn JavaScript on. Feature: Oral Health and Aging Oral Health and Aging Past Issues / Summer 2016 Table of ... years. He spoke with NIH MedlinePlus magazine about oral health issues common in older adults. What has been ...

  17. Oral Cancer Exam

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    Full Text Available ... Dental and Craniofacial Research (NIDCR) Improving the Nation's Oral Health National Institutes of Health Español Staff Directory A– ... Index Search Text size: Website Contents NIDCR Home Oral Health Diseases and Conditions Gum Disease TMJ Disorders Oral ...

  18. Oral Health in Rural Communities

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    ... Guide Rural Health Topics & States Topics View more Oral Health in Rural Communities Adequate access to oral healthcare ... about oral health programs in my area? What oral health disparities are present in rural America? According to ...

  19. Rescue of Drosophila Melanogaster l(2)35Aa lethality is only mediated by polypeptide GalNAc-transferase pgant35A, but not by the evolutionary conserved human ortholog GalNAc-transferase-T11

    DEFF Research Database (Denmark)

    Bennett, Eric P; Chen, Ya-Wen; Schwientek, Tilo;

    2010-01-01

    conserved family of genes encoding polypeptide GalNAc-transferases. Phylogenetic and functional analyses have proposed that subfamilies of orthologous GalNAc-transferase genes are conserved in species, suggesting that they serve distinct functions in vivo. Based on sequence alignments, pgant35A and human......)35Aa lethality. By use of genetic "domain swapping" experiments we demonstrate, that lack of rescue was not caused by inappropriate sub-cellular targeting of functionally active GalNAc-T11. Collectively our results show, that fly embryogenesis specifically requires functional pgant35A......, and that the presence of this gene product during fly embryogenesis is functionally distinct from other Drosophila GalNAc-transferase isoforms and from the proposed human ortholog GALNT11....

  20. Infant oral health and oral habits.

    Science.gov (United States)

    Nowak, A J; Warren, J J

    2000-10-01

    Many oral diseases and conditions, including dental caries (cavities) and malocclusions, have their origins early in life. Prudent anticipatory guidance by the medical and dental professions can help prevent many of the more common oral health problems. This article provides information on the rationale for early dental examination and instructions for pediatric and family practitioners in scheduling and conducting an early oral intervention appointment. In addition, feeding practices, non-nutritive sucking, mouth breathing, and bruxing are discussed, including their effects on orofacial growth and development.

  1. Oral steroid contraception.

    Science.gov (United States)

    Sech, Laura A; Mishell, Daniel R

    2015-11-01

    Oral steroid contraception is a popular method of family planning worldwide. Over the past several decades, this method of contraception has changed significantly by decreasing the estrogen dose, changing the progestin component, and reducing the hormone free interval. Despite the popularity of oral steroid contraception, there has been much criticism regarding the associated risks of venous thromboembolism and stroke. Despite these established, yet uncommon risks, oral steroid contraception has many important health benefits. This review highlights the available formulations of oral contraceptives along with their evidence-based associated risks and benefits. Highlights regarding future directions for development of novel oral contraceptives are also addressed.

  2. Characterization of glutathione S-transferase from dwarf pine needles (Pinus mugo Turra).

    Science.gov (United States)

    Schröder, P; Rennenberg, H

    1992-09-01

    Glutathione S-transferase activity conjugating xenobiotics with glutathione (GSH) was found in extracts from needles of dwarf pine (Pinus mugo Turra). In vivo incubation of needle segments with the herbicide fluorodifen at 25 degrees C resulted in conversion of the xenobiotic to water-soluble products at initial rates of 0.7 nmol h(-1) g(fw) (-1). At 15 degrees C, the initial rate of product formation was decreased to 0.1 nmol h(-1) g(fw) (-1). In vitro conjugation studies with chloro-2,4-dinitrobenzene (CDNB) and 1,2-dichloro-4-nitrobenzene (DCNB) as model substrates gave apparent K(m) values of 0.5 mM GSH and 1.14 mM CDNB in the GSH/CDNB system and 0.3 mM GSH and 0.44 mM DCNB in the GSH/DCNB system. The pH optimum was between 7.7 and 7.9 for both the GSH/CDNB and the GSH/DCNB systems. The temperature optimum for these model substrates was between 30 and 35 degrees C, and only minute amounts of enzyme activity were detected at 15 degrees C. The activation energy in the temperature range of 15 to 30 degrees C was 46 kJ mol(-1). Dwarf pine glutathione S-transferase exhibited an approximate molecular weight of 52 kD.

  3. Characterisation of the Candida albicans Phosphopantetheinyl Transferase Ppt2 as a Potential Antifungal Drug Target.

    Directory of Open Access Journals (Sweden)

    Katharine S Dobb

    Full Text Available Antifungal drugs acting via new mechanisms of action are urgently needed to combat the increasing numbers of severe fungal infections caused by pathogens such as Candida albicans. The phosphopantetheinyl transferase of Aspergillus fumigatus, encoded by the essential gene pptB, has previously been identified as a potential antifungal target. This study investigated the function of its orthologue in C. albicans, PPT2/C1_09480W by placing one allele under the control of the regulatable MET3 promoter, and deleting the remaining allele. The phenotypes of this conditional null mutant showed that, as in A. fumigatus, the gene PPT2 is essential for growth in C. albicans, thus fulfilling one aspect of an efficient antifungal target. The catalytic activity of Ppt2 as a phosphopantetheinyl transferase and the acyl carrier protein Acp1 as a substrate were demonstrated in a fluorescence transfer assay, using recombinant Ppt2 and Acp1 produced and purified from E.coli. A fluorescence polarisation assay amenable to high-throughput screening was also developed. Therefore we have identified Ppt2 as a broad-spectrum novel antifungal target and developed tools to identify inhibitors as potentially new antifungal compounds.

  4. Lectin domains of polypeptide GalNAc transferases exhibit glycopeptide binding specificity.

    Science.gov (United States)

    Pedersen, Johannes W; Bennett, Eric P; Schjoldager, Katrine T-B G; Meldal, Morten; Holmér, Andreas P; Blixt, Ola; Cló, Emiliano; Levery, Steven B; Clausen, Henrik; Wandall, Hans H

    2011-09-16

    UDP-GalNAc:polypeptide α-N-acetylgalactosaminyltransferases (GalNAc-Ts) constitute a family of up to 20 transferases that initiate mucin-type O-glycosylation. The transferases are structurally composed of catalytic and lectin domains. Two modes have been identified for the selection of glycosylation sites by GalNAc-Ts: confined sequence recognition by the catalytic domain alone, and concerted recognition of acceptor sites and adjacent GalNAc-glycosylated sites by the catalytic and lectin domains, respectively. Thus far, only the catalytic domain has been shown to have peptide sequence specificity, whereas the primary function of the lectin domain is to increase affinity to previously glycosylated substrates. Whether the lectin domain also has peptide sequence selectivity has remained unclear. Using a glycopeptide array with a library of synthetic and recombinant glycopeptides based on sequences of mucins MUC1, MUC2, MUC4, MUC5AC, MUC6, and MUC7 as well as a random glycopeptide bead library, we examined the binding properties of four different lectin domains. The lectin domains of GalNAc-T1, -T2, -T3, and -T4 bound different subsets of small glycopeptides. These results indicate an additional level of complexity in the initiation step of O-glycosylation by GalNAc-Ts.

  5. Conductimetric assays for the hydrolase and transferase activities of phospholipase D enzymes.

    Science.gov (United States)

    Mezna, M; Lawrence, A J

    1994-05-01

    Measurement of solution electrical conductance (conductimetry) is a simple direct assay method for the protogenic, hydrolytic reactions catalyzed by all phospholipase enzymes. The technique is especially suitable for assay of phospholipase D (PLD) enzymes where cleavage of zwitterionic substrates reinforces the pH dependent conductance change and allows the method to be used over a much wider pH range than the equivalent titrimetric assay. The ability to detect zwitterion cleavage enables the method to assay reactions in which phospholipase D transfers neutral, or anionic, alcohol species to the zwitterionic substrates phosphatidyl choline and phosphatidyl ethanolamine. The method can follow the sequential attack by different phospholipases and provides a simple technique for investigating the effect of substrate structure on susceptibility to various phospholipase enzymes. The results confirm that PLD from Streptomyces chromofuscus can attack lysophospholipids, but cannot transfer primary alcohols to the phosphatidyl residue, while the PLD from savoy cabbage is an efficient transferase, but cannot attack lysophospholipids. The data suggest that the bacterial PLD fails to act as a transferase because it hydrolyzes the transphosphatidylation products. Some phosphatidyl alcohols are more highly susceptible to PLA2 attack than the parent phosphatidyl choline derivatives.

  6. Selective inhibitors of glutathione transferase P1 with trioxane structure as anticancer agents.

    Science.gov (United States)

    Bräutigam, Maria; Teusch, Nicole; Schenk, Tobias; Sheikh, Miriam; Aricioglu, Rocky Z; Borowski, Swantje H; Neudörfl, Jörg-Martin; Baumann, Ulrich; Griesbeck, Axel G; Pietsch, Markus

    2015-04-01

    The response to chemotherapy in cancer patients is frequently compromised by drug resistance. Although chemoresistance is a multifactorial phenomenon, many studies have demonstrated that altered drug metabolism through the expression of phase II conjugating enzymes, including glutathione transferases (GSTs), in tumor cells can be directly correlated with resistance against a wide range of marketed anticancer drugs. In particular, overexpression of glutathione transferase P1 (GSTP1) appears to be a factor for poor prognosis during cancer therapy. Former and ongoing clinical trials have confirmed GSTP1 inhibition as a principle for antitumor therapy. A new series of 1,2,4-trioxane GSTP1 inhibitors were designed via a type II photooxygenation route of allylic alcohols followed by acid-catalyzed peroxyacetalization with aldehydes. A set of novel inhibitors exhibit low micromolar to high nanomolar inhibition of GSTP1, revealing preliminary SAR for further lead optimization. Importantly, high selectivity over another two human GST classes (GSTA1 and GSTM2) has been achieved. The trioxane GSTP1 inhibitors may therefore serve as a basis for the development of novel drug candidates in overcoming chemoresistance.

  7. Substrate profiling of glutathione S-transferase with engineered enzymes and matched glutathione analogues.

    Science.gov (United States)

    Feng, Shan; Zhang, Lei; Adilijiang, Gulishana; Liu, Jieyuan; Luo, Minkui; Deng, Haiteng

    2014-07-01

    The identification of specific substrates of glutathione S-transferases (GSTs) is important for understanding drug metabolism. A method termed bioorthogonal identification of GST substrates (BIGS) was developed, in which a reduced glutathione (GSH) analogue was developed for recognition by a rationally engineered GST to label the substrates of the corresponding native GST. A K44G-W40A-R41A mutant (GST-KWR) of the mu-class glutathione S-transferases GSTM1 was shown to be active with a clickable GSH analogue (GSH-R1) as the cosubstrate. The GSH-R1 conjugation products can react with an azido-based biotin probe for ready enrichment and MS identification. Proof-of-principle studies were carried to detect the products of GSH-R1 conjugation to 1-chloro-2,4-dinitrobenzene (CDNB) and dopamine quinone. The BIGS technology was then used to identify GSTM1 substrates in the Chinese herbal medicine Ganmaocongji.

  8. Binding properties of ferrocene-glutathione conjugates as inhibitors and sensors for glutathione S-transferases.

    Science.gov (United States)

    Martos-Maldonado, Manuel C; Casas-Solvas, Juan M; Téllez-Sanz, Ramiro; Mesa-Valle, Concepción; Quesada-Soriano, Indalecio; García-Maroto, Federico; Vargas-Berenguel, Antonio; García-Fuentes, Luís

    2012-02-01

    The binding properties of two electroactive glutathione-ferrocene conjugates that consist in glutathione attached to one or both of the cyclopentadienyl rings of ferrocene (GSFc and GSFcSG), to Schistosoma japonica glutathione S-transferase (SjGST) were studied by spectroscopy fluorescence, isothermal titration calorimetry (ITC) and differential pulse voltammetry (DPV). Such ferrocene conjugates resulted to be competitive inhibitors of glutathione S-transferase with an increased binding affinity relative to the natural substrate glutathione (GSH). We found that the conjugate having two glutathione units (GSFcSG) exhibits an affinity for SjGST approximately two orders of magnitude higher than GSH. Furthermore, it shows negative cooperativity with the affinity for the second binding site two orders of magnitude lower than that for the first one. We propose that the reason for such negative cooperativity is steric since, i) the obtained thermodynamic parameters do not indicate profound conformational changes upon GSFcSG binding and ii) docking studies have shown that, when bound, part of the first bound ligand invades the second site due to its large size. In addition, voltammetric measurements show a strong decrease of the peak current upon binding of ferrocene-glutathione conjugates to SjGST and provide very similar K values than those obtained by ITC. Moreover, the sensing ability, expressed by the sensitivity parameter shows that GSFcSG is much more sensitive than GSFc, for the detection of SjGST.

  9. Structure of Human O-GlcNAc Transferase and its Complex with a Peptide Substrate

    Energy Technology Data Exchange (ETDEWEB)

    M Lazarus; Y Nam; J Jiang; P Sliz; S Walker

    2011-12-31

    The essential mammalian enzyme O-linked {beta}-N-acetylglucosamine transferase (O-GlcNAc transferase, here OGT) couples metabolic status to the regulation of a wide variety of cellular signalling pathways by acting as a nutrient sensor. OGT catalyses the transfer of N-acetylglucosamine from UDP-N-acetylglucosamine (UDP-GlcNAc) to serines and threonines of cytoplasmic, nuclear and mitochondrial proteins, including numerous transcription factors, tumour suppressors, kinases, phosphatases and histone-modifying proteins. Aberrant glycosylation by OGT has been linked to insulin resistance, diabetic complications, cancer and neurodegenerative diseases including Alzheimer's. Despite the importance of OGT, the details of how it recognizes and glycosylates its protein substrates are largely unknown. We report here two crystal structures of human OGT, as a binary complex with UDP (2.8 {angstrom} resolution) and as a ternary complex with UDP and a peptide substrate (1.95 {angstrom}). The structures provide clues to the enzyme mechanism, show how OGT recognizes target peptide sequences, and reveal the fold of the unique domain between the two halves of the catalytic region. This information will accelerate the rational design of biological experiments to investigate OGT's functions; it will also help the design of inhibitors for use as cellular probes and help to assess its potential as a therapeutic target.

  10. Indication for joint replacement and glutathione s-transferases M1 and T1 genotypes.

    Science.gov (United States)

    Klein, Torsten; Selinski, Silvia; Blaszkewicz, Meinolf; Hengstler, Jan G; Golka, Klaus

    2012-01-01

    In most patients with osteoarthritis (OA), therapy-resistant pain is the indication for hip or knee replacement. Glutathione S-transferases, particularly glutathione S-transferase M1 (GSTM1), are involved in metabolism of highly reactive metabolites that may be generated by inflammatory processes. In total, 148 patients with indication for hip or knee replacement and 129 patients of the same hospital without indication for joint replacement were genotyped for GSTM1 and GSTT1 and interviewed by a newly developed questionnaire for occupational and nonoccupational risk factors of hip and/or knee osteoarthritis. Mean age was 70.9 yr in OA cases and 67.4 yr in controls. The frequency of GSTM1 negative in the OA case group was (45%) in the lower range compared to values in Caucasian general population (approximately 50%), whereas the frequency in the controls was normal (51%). The frequency of GSTT1 negative genotype in OA cases and controls was normal. The normal distribution of the GSTM1 negative genotype in patients with indication for hip or knee replacement indicates that the role GSTM1 in these patients is different from that in other aseptic inflammatory diseases such as ozone-related inflammatory reactions of the respiratory tract.

  11. Miners compensated for pneumoconiosis and glutathione s-transferases M1 and T1 genotypes.

    Science.gov (United States)

    Zimmermann, Anna; Ebbinghaus, Rainer; Prager, Hans-Martin; Blaszkewicz, Meinolf; Hengstler, Jan G; Golka, Klaus

    2012-01-01

    Chronic inhalation of quartz-containing dust produces reversible inflammatory changes in lungs resulting in irreversible fibrotic changes termed pneumoconiosis. Due to the inflammatory process in the lungs, highly reactive substances are released that may be detoxified by glutathione S-transferases. Therefore, 90 hard coal miners with pneumoconiosis as a recognized occupational disease (in Germany: Berufskrankheit BK 4101) were genotyped for glutathione S-transferases M1 (GSTM1) and T1 (GSTT1) according to standard methods. Furthermore, occupational exposure and smoking habits were assessed by questionnaire. Changes in a chest x-ray were classified according to ILO classification 2000. Of the investigated hard coal miners 43% were GSTM1 negative whereas 57% were GSTM1 positive. The arithmetic mean of the age at time of investigation was 74.2 yr (range: 42-87 yr). Seventy-four percent of the hard coal miners reported being ever smokers, while 26% denied smoking. All hard coal miners provided pneumoconiosis-related changes in the chest x-ray. The observed frequency of GSTM1 negative hard coal miners was not different from frequencies reported for general Caucasian populations and in agreement with findings reported for Chinese coal miners. In contrast, in a former study, 16 of 19 German hard coal miners (84%) with urinary bladder cancer displayed a GSTM1 negative genotype. The outcome of this study provides evidence that severely occupationally exposed Caucasian hard coal miners do not present an elevated level of GSTM1 negative individuals.

  12. Madumycin II inhibits peptide bond formation by forcing the peptidyl transferase center into an inactive state

    Energy Technology Data Exchange (ETDEWEB)

    Osterman, Ilya A.; Khabibullina, Nelli F.; Komarova, Ekaterina S.; Kasatsky, Pavel; Kartsev, Victor G.; Bogdanov, Alexey A.; Dontsova, Olga A.; Konevega, Andrey L.; Sergiev, Petr V.; Polikanov, Yury S. (InterBioScreen); (UIC); (MSU-Russia); (Kurchatov)

    2017-05-13

    The emergence of multi-drug resistant bacteria is limiting the effectiveness of commonly used antibiotics, which spurs a renewed interest in revisiting older and poorly studied drugs. Streptogramins A is a class of protein synthesis inhibitors that target the peptidyl transferase center (PTC) on the large subunit of the ribosome. In this work, we have revealed the mode of action of the PTC inhibitor madumycin II, an alanine-containing streptogramin A antibiotic, in the context of a functional 70S ribosome containing tRNA substrates. Madumycin II inhibits the ribosome prior to the first cycle of peptide bond formation. It allows binding of the tRNAs to the ribosomal A and P sites, but prevents correct positioning of their CCA-ends into the PTC thus making peptide bond formation impossible. We also revealed a previously unseen drug-induced rearrangement of nucleotides U2506 and U2585 of the 23S rRNA resulting in the formation of the U2506•G2583 wobble pair that was attributed to a catalytically inactive state of the PTC. The structural and biochemical data reported here expand our knowledge on the fundamental mechanisms by which peptidyl transferase inhibitors modulate the catalytic activity of the ribosome.

  13. Structural determinants of glutathione transferases with azathioprine activity identified by DNA shuffling of alpha class members.

    Science.gov (United States)

    Kurtovic, Sanela; Modén, Olof; Shokeer, Abeer; Mannervik, Bengt

    2008-02-01

    A library of alpha class glutathione transferases (GSTs), composed of chimeric enzymes derived from human (A1-1, A2-2 and A3-3), bovine (A1-1) and rat (A2-2 and A3-3) cDNA sequences was constructed by the method of DNA shuffling. The GST variants were screened in bacterial lysates for activity with the immunosuppressive agent azathioprine, a prodrug that is transformed into its active form, 6-mercaptopurine, by reaction with the tripeptide glutathione catalyzed by GSTs. Important structural determinants for activity with azathioprine were recognized by means of primary structure analysis and activities of purified enzymes chosen from the screening. The amino acid sequences could be divided into 23 exchangeable segments on the basis of the primary structures of 45 chosen clones. Segments 2, 20, 21, and 22 were identified as primary determinants of the azathioprine activity representing two of the regions forming the substrate-binding H-site. Segments 21 and 22 are situated in the C-terminal helix characterizing alpha class GSTs, which is instrumental in their catalytic function. The study demonstrates the power of DNA shuffling in identifying segments of primary structure that are important for catalytic activity with a targeted substrate. GSTs in combination with azathioprine have potential as selectable markers for use in gene therapy. Knowledge of activity-determining segments in the structure is valuable in the protein engineering of glutathione transferase for enhanced or suppressed activity.

  14. Mitochondrial glutathione transferases involving a new function for membrane permeability transition pore regulation.

    Science.gov (United States)

    Aniya, Yoko; Imaizumi, Naoki

    2011-05-01

    The mitochondria in mammalian cells are a predominant resource of reactive oxygen species (ROS), which are produced during respiration-coupled oxidative metabolism or various chemical stresses. End-products from membrane-lipid peroxidation caused by ROS are highly toxic, thereby their elimination/scavenging are protective of mitochondria and cells against oxidative damages. In mitochondria, soluble (kappa, alpha, mu, pi, zeta) and membrane-bound glutathione transferases (GSTs) (MGST1) are distributed. Mitochondrial GSTs display both glutathione transferase and peroxidase activities that detoxify such harmful products through glutathione (GSH) conjugation or GSH-mediated peroxide reduction. Some GST isoenzymes are induced by oxidative stress, an adaptation mechanism for the protection of cells from oxidative stress. Membrane-bound MGST1 is activated through the thiol modification in oxidative conditions. Protective action of MGST1 against oxidative stress has been confirmed using MCF7 cells highly expressed of MGST1. In recent years, mitochondria have been recognized as a regulator of cell death via both apoptosis and necrosis, where oxidative stress-induced alteration of the membrane permeability is an important step. Recent studies have shown that MGST1 in the inner mitochondrial membrane could interact with the mitochondrial permeability transition (MPT) regulator proteins, such as adenine nucleotide translocator (ANT) and/or cyclophilin D, and could contribute to oxidant-induced MPT pores. Interaction of GST alpha with ANT has also been shown. In this review, functions of the mitochondrial GSTs, including a new role for mitochondria-mediated cell death, are described.

  15. Glutathione Transferases Superfamily: Cold-Inducible Expression of Distinct GST Genes in Brassica oleracea.

    Science.gov (United States)

    Vijayakumar, Harshavardhanan; Thamilarasan, Senthil Kumar; Shanmugam, Ashokraj; Natarajan, Sathishkumar; Jung, Hee-Jeong; Park, Jong-In; Kim, HyeRan; Chung, Mi-Young; Nou, Ill-Sup

    2016-07-27

    Plants, as sessile organisms, can suffer serious growth and developmental consequences under cold stress conditions. Glutathione transferases (GSTs, EC 2.5.1.18) are ubiquitous and multifunctional conjugating proteins, which play a major role in stress responses by preventing oxidative damage by reactive oxygen species (ROS). Currently, understanding of their function(s) during different biochemical and signaling pathways under cold stress condition remain unclear. In this study, using combined computational strategy, we identified 65 Brassica oleracea glutathione transferases (BoGST) and characterized them based on evolutionary analysis into 11 classes. Inter-species and intra-species duplication was evident between BoGSTs and Arabidopsis GSTs. Based on localization analyses, we propose possible pathways in which GST genes are involved during cold stress. Further, expression analysis of the predicted putative functions for GST genes were investigated in two cold contrasting genotypes (cold tolerance and susceptible) under cold condition, most of these genes were highly expressed at 6 h and 1 h in the cold tolerant (CT) and cold susceptible (CS) lines, respectively. Overall, BoGSTU19, BoGSTU24, BoGSTF10 are candidate genes highly expressed in B. oleracea. Further investigation of GST superfamily in B. oleracea will aid in understanding complex mechanism underlying cold tolerance in plants.

  16. Isoenzyme profile of glutathione transferases in transitional cell carcinoma of upper urinary tract.

    Science.gov (United States)

    Matic, Marija; Simic, Tatjana; Dragicevic, Dejan; Mimic-Oka, Jasmina; Pljesa-Ercegovac, Marija; Savic-Radojevic, Ana

    2010-05-01

    Upregulated glutathione S-transferase P1 (GSTP1) plays an important role in the resistance to apoptosis in transitional cell carcinoma (TCC) of the urinary bladder (UB) and represents a potential target for chemotherapeutic agents. Our aim was to perform a systematic investigation of a glutathione S-transferase (GST) isoenzyme profile (GSTM, GSTP1, and GSTT1) in the upper urinary tract (UUT) TCC and compare it with the GST isoenzyme pattern of the UB TCC and normal urothelium. We examined GST activity spectrophotometrically by using substrates for the overall GST activity, GSTP1, and GSTT1 in the cytosolic fraction. GSTP1 and GSTM expression was analyzed by Western blotting. The results obtained have shown that the overall GST activity was significantly higher in UUT TCC in comparison with urothelium (P0.05). We conclude that 3 major cytosolic GST classes, GSTM, GSTP1, and GSTT1, are expressed in the UUT TCC. The isoenzyme profile of GST in the UUT TCC is similar to that observed in the UB TCC; it shows essentially the same alteration of the GST phenotype in the course of cancerization. The association of GSTT1 and GSTP1 upregulation with the malignant phenotype of the UUT TCC might result in resistances to both chemotherapy and apoptosis.

  17. Functional Diversification of Fungal Glutathione Transferases from the Ure2p Class

    Directory of Open Access Journals (Sweden)

    Anne Thuillier

    2011-01-01

    Full Text Available The glutathione-S-transferase (GST proteins represent an extended family involved in detoxification processes. They are divided into various classes with high diversity in various organisms. The Ure2p class is especially expanded in saprophytic fungi compared to other fungi. This class is subdivided into two subclasses named Ure2pA and Ure2pB, which have rapidly diversified among fungal phyla. We have focused our analysis on Basidiomycetes and used Phanerochaete chrysosporium as a model to correlate the sequence diversity with the functional diversity of these glutathione transferases. The results show that among the nine isoforms found in P. chrysosporium, two belonging to Ure2pA subclass are exclusively expressed at the transcriptional level in presence of polycyclic aromatic compounds. Moreover, we have highlighted differential catalytic activities and substrate specificities between Ure2pA and Ure2pB isoforms. This diversity of sequence and function suggests that fungal Ure2p sequences have evolved rapidly in response to environmental constraints.

  18. Glutathione Transferases Superfamily: Cold-Inducible Expression of Distinct GST Genes in Brassica oleracea

    Directory of Open Access Journals (Sweden)

    Harshavardhanan Vijayakumar

    2016-07-01

    Full Text Available Plants, as sessile organisms, can suffer serious growth and developmental consequences under cold stress conditions. Glutathione transferases (GSTs, EC 2.5.1.18 are ubiquitous and multifunctional conjugating proteins, which play a major role in stress responses by preventing oxidative damage by reactive oxygen species (ROS. Currently, understanding of their function(s during different biochemical and signaling pathways under cold stress condition remain unclear. In this study, using combined computational strategy, we identified 65 Brassica oleracea glutathione transferases (BoGST and characterized them based on evolutionary analysis into 11 classes. Inter-species and intra-species duplication was evident between BoGSTs and Arabidopsis GSTs. Based on localization analyses, we propose possible pathways in which GST genes are involved during cold stress. Further, expression analysis of the predicted putative functions for GST genes were investigated in two cold contrasting genotypes (cold tolerance and susceptible under cold condition, most of these genes were highly expressed at 6 h and 1 h in the cold tolerant (CT and cold susceptible (CS lines, respectively. Overall, BoGSTU19, BoGSTU24, BoGSTF10 are candidate genes highly expressed in B. oleracea. Further investigation of GST superfamily in B. oleracea will aid in understanding complex mechanism underlying cold tolerance in plants.

  19. Functional diversification of fungal glutathione transferases from the ure2p class.

    Science.gov (United States)

    Thuillier, Anne; Ngadin, Andrew A; Thion, Cécile; Billard, Patrick; Jacquot, Jean-Pierre; Gelhaye, Eric; Morel, Mélanie

    2011-01-01

    The glutathione-S-transferase (GST) proteins represent an extended family involved in detoxification processes. They are divided into various classes with high diversity in various organisms. The Ure2p class is especially expanded in saprophytic fungi compared to other fungi. This class is subdivided into two subclasses named Ure2pA and Ure2pB, which have rapidly diversified among fungal phyla. We have focused our analysis on Basidiomycetes and used Phanerochaete chrysosporium as a model to correlate the sequence diversity with the functional diversity of these glutathione transferases. The results show that among the nine isoforms found in P. chrysosporium, two belonging to Ure2pA subclass are exclusively expressed at the transcriptional level in presence of polycyclic aromatic compounds. Moreover, we have highlighted differential catalytic activities and substrate specificities between Ure2pA and Ure2pB isoforms. This diversity of sequence and function suggests that fungal Ure2p sequences have evolved rapidly in response to environmental constraints.

  20. Evolutionary divergence of Ure2pA glutathione transferases in wood degrading fungi.

    Science.gov (United States)

    Roret, Thomas; Thuillier, Anne; Favier, Frédérique; Gelhaye, Eric; Didierjean, Claude; Morel-Rouhier, Mélanie

    2015-10-01

    The intracellular systems of detoxification are crucial for the survival of wood degrading fungi. Within these systems, glutathione transferases could play a major role since this family of enzymes is specifically extended in lignolytic fungi. In particular the Ure2p class represents one third of the total GST number in Phanerochaete chrysosporium. These proteins have been phylogenetically split into two subclasses called Ure2pA and Ure2pB. Ure2pB can be classified as Nu GSTs because of shared structural and functional features with previously characterized bacterial isoforms. Ure2pA can rather be qualified as Nu-like GSTs since they exhibit a number of differences. Ure2pA possess a classical transferase activity, a more divergent catalytic site and a higher structural flexibility for some of them, compared to Nu GSTs. The characterization of four members of this Ure2pA subclass (PcUre2pA4, PcUre2pA5, PcUre2pA6 and PcUre2pA8) revealed specific functional and structural features, suggesting that these enzymes have rapidly evolved and differentiated, probably to adapt to the complex chemical environment associated with wood decomposition.

  1. Catalytic and structural diversity of the fluazifop-inducible glutathione transferases from Phaseolus vulgaris.

    Science.gov (United States)

    Chronopoulou, Evangelia; Madesis, Panagiotis; Asimakopoulou, Basiliki; Platis, Dimitrios; Tsaftaris, Athanasios; Labrou, Nikolaos E

    2012-06-01

    Plant glutathione transferases (GSTs) comprise a large family of inducible enzymes that play important roles in stress tolerance and herbicide detoxification. Treatment of Phaseolus vulgaris leaves with the aryloxyphenoxypropionic herbicide fluazifop-p-butyl resulted in induction of GST activities. Three inducible GST isoenzymes were identified and separated by affinity chromatography. Their full-length cDNAs with complete open reading frame were isolated using RACE-RT and information from N-terminal amino acid sequences. Analysis of the cDNA clones showed that the deduced amino acid sequences share high homology with GSTs that belong to phi and tau classes. The three isoenzymes were expressed in E. coli and their substrate specificity was determined towards 20 different substrates. The results showed that the fluazifop-inducible glutathione transferases from P. vulgaris (PvGSTs) catalyze a broad range of reactions and exhibit quite varied substrate specificity. Molecular modeling and structural analysis was used to identify key structural characteristics and to provide insights into the substrate specificity and the catalytic mechanism of these enzymes. These results provide new insights into catalytic and structural diversity of GSTs and the detoxifying mechanism used by P. vulgaris.

  2. Expression of glutathione transferases in corneal cell lines, corneal tissues and a human cornea construct.

    Science.gov (United States)

    Kölln, Christian; Reichl, Stephan

    2016-06-15

    Glutathione transferase (GST) expression and activity were examined in a three-dimensional human cornea construct and were compared to those of excised animal corneas. The objective of this study was to characterize phase II enzyme expression in the cornea construct with respect to its utility as an alternative to animal cornea models. The expression of the GSTO1-1 and GSTP1-1 enzymes was investigated using immunofluorescence staining and western blotting. The level of total glutathione transferase activity was determined using 1-chloro-2,4- dinitrobenzene as the substrate. Furthermore, the levels of GSTO1-1 and GSTP1-1 activity were examined using S-(4-nitrophenacyl)glutathione and ethacrynic acid, respectively, as the specific substrates. The expression and activity levels of these enzymes were examined in the epithelium, stroma and endothelium, the three main cellular layers of the cornea. In summary, the investigated enzymes were detected at both the protein and functional levels in the cornea construct and the excised animal corneas. However, the enzymatic activity levels of the human cornea construct were lower than those of the animal corneas.

  3. Crystal Structure of Escherichia coli originated MCR-1, a phosphoethanolamine transferase for Colistin Resistance.

    Science.gov (United States)

    Hu, Menglong; Guo, Jiubiao; Cheng, Qipeng; Yang, Zhiqiang; Chan, Edward Wai Chi; Chen, Sheng; Hao, Quan

    2016-12-13

    MCR-1 is a phosphoethanolamine (pEtN) transferase that modifies the pEtN moiety of lipid A, conferring resistance to colistin, which is an antibiotic belonging to the class of polypeptide antibiotics known as polymyxins and is the last-line antibiotic used to treat multidrug resistant bacterial infections. Here we determined the crystal structure of the catalytic domain of MCR-1 (MCR-1-ED), which is originated in Escherichia coli (E. coli). MCR-1-ED was found to comprise several classical β-α-β-α motifs that constitute a "sandwich" conformation. Two interlaced molecules with different phosphorylation status of the residue T285 could give rise to two functional statuses of MCR-1 depending on the physiological conditions. MCR-1, like other known pEtN transferases, possesses an enzymatic site equipped with zinc binding residues. Interestingly, two zinc ions were found to mediate intermolecular interactions between MCR-1-ED molecules in one asymmetric unit and hence concatenation of MCR-1, allowing the protein to be oligomer. Findings of this work shall provide important insight into development of effective and clinically useful inhibitors of MCR-1 or structurally similar enzymes.

  4. Riboswitch control of induction of aminoglycoside resistance acetyl and adenyl-transferases.

    Science.gov (United States)

    He, Weizhi; Zhang, Xuhui; Zhang, Jun; Jia, Xu; Zhang, Jing; Sun, Wenxia; Jiang, Hengyi; Chen, Dongrong; Murchie, Alastair I H

    2013-08-01

    The acquisition of antibiotic resistance by human pathogens poses a significant threat to public health. The mechanisms that control the proliferation and expression of antibiotic resistance genes are not yet completely understood. The aminoglycosides are a historically important class of antibiotics that were introduced in the 1940s. Aminoglycoside resistance is conferred most commonly through enzymatic modification of the drug or enzymatic modification of the target rRNA through methylation or through the overexpression of efflux pumps. In our recent paper, we reported that expression of the aminoglycoside resistance genes encoding the aminoglycoside acetyl transferase (AAC) and aminoglycoside adenyl transferase (AAD) enzymes was controlled by an aminoglycoside-sensing riboswitch RNA. This riboswitch is embedded in the leader RNA of the aac/aad genes and is associated with the integron cassette system. The leader RNA can sense and bind specific aminoglycosides such that the binding causes a structural transition in the leader RNA, which leads to the induction of aminoglycoside antibiotic resistance. Specific aminoglycosides induce reporter gene expression mediated by the leader RNA. Aminoglycoside RNA binding was measured directly and, aminoglycoside-induced changes in RNA structure monitored by chemical probing. UV cross-linking and mutational analysis identified potential aminoglycoside binding sites on the RNA.

  5. Structure of a lipid A phosphoethanolamine transferase suggests how conformational changes govern substrate binding.

    Science.gov (United States)

    Anandan, Anandhi; Evans, Genevieve L; Condic-Jurkic, Karmen; O'Mara, Megan L; John, Constance M; Phillips, Nancy J; Jarvis, Gary A; Wills, Siobhan S; Stubbs, Keith A; Moraes, Isabel; Kahler, Charlene M; Vrielink, Alice

    2017-02-28

    Multidrug-resistant (MDR) gram-negative bacteria have increased the prevalence of fatal sepsis in modern times. Colistin is a cationic antimicrobial peptide (CAMP) antibiotic that permeabilizes the bacterial outer membrane (OM) and has been used to treat these infections. The OM outer leaflet is comprised of endotoxin containing lipid A, which can be modified to increase resistance to CAMPs and prevent clearance by the innate immune response. One type of lipid A modification involves the addition of phosphoethanolamine to the 1 and 4' headgroup positions by phosphoethanolamine transferases. Previous structural work on a truncated form of this enzyme suggested that the full-length protein was required for correct lipid substrate binding and catalysis. We now report the crystal structure of a full-length lipid A phosphoethanolamine transferase from Neisseria meningitidis, determined to 2.75-Å resolution. The structure reveals a previously uncharacterized helical membrane domain and a periplasmic facing soluble domain. The domains are linked by a helix that runs along the membrane surface interacting with the phospholipid head groups. Two helices located in a periplasmic loop between two transmembrane helices contain conserved charged residues and are implicated in substrate binding. Intrinsic fluorescence, limited proteolysis, and molecular dynamics studies suggest the protein may sample different conformational states to enable the binding of two very different- sized lipid substrates. These results provide insights into the mechanism of endotoxin modification and will aid a structure-guided rational drug design approach to treating multidrug-resistant bacterial infections.

  6. High yield production of myristoylated Arf6 small GTPase by recombinant N-myristoyl transferase

    Science.gov (United States)

    Padovani, Dominique; Zeghouf, Mahel; Traverso, José A.; Giglione, Carmela; Cherfils, Jacqueline

    2013-01-01

    Small GTP-binding proteins of the Arf family (Arf GTPases) interact with multiple cellular partners and with membranes to regulate intracellular traffic and organelle structure. Understanding the underlying molecular mechanisms requires in vitro biochemical assays to test for regulations and functions. Such assays should use proteins in their cellular form, which carry a myristoyl lipid attached in N-terminus. N-myristoylation of recombinant Arf GTPases can be achieved by co-expression in E. coli with a eukaryotic N-myristoyl transferase. However, purifying myristoylated Arf GTPases is difficult and has a poor overall yield. Here we show that human Arf6 can be N-myristoylated in vitro by recombinant N-myristoyl transferases from different eukaryotic species. The catalytic efficiency depended strongly on the guanine nucleotide state and was highest for Arf6-GTP. Large-scale production of highly pure N-myristoylated Arf6 could be achieved, which was fully functional for liposome-binding and EFA6-stimulated nucleotide exchange assays. This establishes in vitro myristoylation as a novel and simple method that could be used to produce other myristoylated Arf and Arf-like GTPases for biochemical assays. PMID:23319116

  7. Clinical implications of thymidylate synthetase, dihydropyrimidine dehydrogenase and orotate phosphoribosyl transferase activity levels in colorectal carcinoma following radical resection and administration of adjuvant 5-FU chemotherapy

    Directory of Open Access Journals (Sweden)

    Ishikawa Masashi

    2008-07-01

    Full Text Available Abstract Bckground A number of studies have investigated whether the activity levels of enzymes involved in 5-fluorouracil (5-FU metabolism are prognostic factors for survival in patients with colorectal carcinoma. Most reports have examined thymidylate synthetase (TS and dihydropyrimidine dehydrogenase (DPD in unresectable or metastatic cases, therefore it is unclear whether the activity of these enzymes is of prognostic value in colorectal cancer patients treated with radical resection and adjuvant chemotherapy with 5-FU. Methods This study examined fresh frozen specimens of colorectal carcinoma from 40 patients who had undergone curative operation and were orally administered adjuvant tegafur/uracil (UFT chemotherapy. TS, DPD and orotate phosphoribosyl transferase (OPRT activities were assayed in cancer tissue and adjacent normal tissue and their association with clinicopathological variables was investigated. In addition, the relationships between TS, DPD and OPRT activities and patient survival were examined to determine whether any of these enzymes could be useful prognostic factors. Results While there was no clear relationship between pathological findings and TS or DPD activity, OPRT activity was significantly lower in tumors with lymph node metastasis than in tumors lacking lymph node metastasis. Postoperative survival was significantly better in the groups with low TS activity and/or high OPRT activity. Conclusion TS and OPRT activity levels in tumor tissue may be important prognostic factors for survival in Dukes' B and C colorectal carcinoma with radical resection and adjuvant chemotherapy with UFT.

  8. Oral biopsy: Oral pathologist′s perspective

    Directory of Open Access Journals (Sweden)

    K L Kumaraswamy

    2012-01-01

    Full Text Available Many oral lesions may need to be diagnosed by removing a sample of tissue from the oral cavity. Biopsy is widely used in the medical field, but the practice is not quite widespread in dental practice. As oral pathologists, we have found many artifacts in the tissue specimen because of poor biopsy technique or handling, which has led to diagnostic pitfalls and misery to both the patient and the clinician. This article aims at alerting the clinicians about the clinical faults arising preoperatively, intraoperatively and postoperatively while dealing with oral biopsy that may affect the histological assessment of the tissue and, therefore, the diagnosis. It also reviews the different techniques, precautions and special considerations necessary for specific lesions.

  9. A study of the prognostic role of serum fucose and fucosyl transferase in cancer of the uterine cervix.

    Directory of Open Access Journals (Sweden)

    Sen,Urmi

    1985-04-01

    Full Text Available Serum fucose levels and fucosyl transferase activities have been designated as nonspecific markers of malignancy, and play an important role in the diagnosis of different types of malignancies. In the present study, attempts were made to determine the prognostic significance of these markers in patients with cancer of the uterine cervix after therapy. It was found that both serum fucose and fucosyl transferase, which were elevated in untreated patients declined significantly in patients responsive to therapy at different follow-up intervals, but not in patients unresponsive to therapy.

  10. A cytosolic glutathione s-transferase, GST-theta from freshwater prawn Macrobrachium rosenbergii: molecular and biochemical properties.

    Science.gov (United States)

    Arockiaraj, Jesu; Gnanam, Annie J; Palanisamy, Rajesh; Bhatt, Prasanth; Kumaresan, Venkatesh; Chaurasia, Mukesh Kumar; Pasupuleti, Mukesh; Ramaswamy, Harikrishnan; Arasu, Abirami; Sathyamoorthi, Akila

    2014-08-10

    Glutathione S-transferases play an important role in cellular detoxification and may have evolved to protect cells against reactive oxygen metabolites. In this study, we report the molecular characterization of glutathione s-transferase-theta (GST-θ) from freshwater prawn Macrobrachium rosenbergii. A full length cDNA of GSTT (1417 base pairs) was isolated and characterized bioinformatically. Exposure to virus (white spot syndrome baculovirus or M. rosenbergii nodovirus), bacteria (Aeromonas hydrophila or Vibrio harveyi) or heavy metals (cadmium or lead) significantly increased the expression of GSTT (Prosenbergii GST-θ in detoxification and possibly conferring immune protection.

  11. Biosynthesis of osmoregulated periplasmic glucans in Escherichia coli: the phosphoethanolamine transferase is encoded by opgE.

    Science.gov (United States)

    Bontemps-Gallo, Sébastien; Cogez, Virginie; Robbe-Masselot, Catherine; Quintard, Kevin; Dondeyne, Jacqueline; Madec, Edwige; Lacroix, Jean-Marie

    2013-01-01

    Osmoregulated periplasmic glucans (OPGs) are oligosaccharides found in the periplasm of many Gram-negative bacteria. Glucose is the sole constitutive sugar and this backbone may be substituted by various kinds of molecules depending on the species. In E. coli, OPG are substituted by phosphoglycerol and phosphoethanolamine derived from membrane phospholipids and by succinyl residues. In this study, we describe the isolation of the opgE gene encoding the phosphoethanolamine transferase by a screen previously used for the isolation of the opgB gene encoding the phosphoglycerol transferase. Both genes show structural and functional similarities without sequence similarity.

  12. Biosynthesis of Osmoregulated Periplasmic Glucans in Escherichia coli: The Phosphoethanolamine Transferase Is Encoded by opgE

    Directory of Open Access Journals (Sweden)

    Sébastien Bontemps-Gallo

    2013-01-01

    Full Text Available Osmoregulated periplasmic glucans (OPGs are oligosaccharides found in the periplasm of many Gram-negative bacteria. Glucose is the sole constitutive sugar and this backbone may be substituted by various kinds of molecules depending on the species. In E. coli, OPG are substituted by phosphoglycerol and phosphoethanolamine derived from membrane phospholipids and by succinyl residues. In this study, we describe the isolation of the opgE gene encoding the phosphoethanolamine transferase by a screen previously used for the isolation of the opgB gene encoding the phosphoglycerol transferase. Both genes show structural and functional similarities without sequence similarity.

  13. Radiation induced oral mucositis

    Directory of Open Access Journals (Sweden)

    P S Satheesh Kumar

    2009-01-01

    Full Text Available Patients receiving radiotherapy or chemotherapy will receive some degree of oral mucositis The incidence of oral mucositis was especially high in patients: (i With primary tumors in the oral cavity, oropharynx, or nasopharynx; (ii who also received concomitant chemotherapy; (iii who received a total dose over 5,000 cGy; and (iv who were treated with altered fractionation radiation schedules. Radiation-induced oral mucositis affects the quality of life of the patients and the family concerned. The present day management of oral mucositis is mostly palliative and or supportive care. The newer guidelines are suggesting Palifermin, which is the first active mucositis drug as well as Amifostine, for radiation protection and cryotherapy. The current management should focus more on palliative measures, such as pain management, nutritional support, and maintenance, of good oral hygiene

  14. Crystal structure of Glycine max glutathione transferase in complex with glutathione: investigation of the mechanism operating by the Tau class glutathione transferases.

    Science.gov (United States)

    Axarli, Irene; Dhavala, Prathusha; Papageorgiou, Anastassios C; Labrou, Nikolaos E

    2009-08-13

    Cytosolic GSTs (glutathione transferases) are a multifunctional group of enzymes widely distributed in Nature and involved in cellular detoxification processes. The three-dimensional structure of GmGSTU4-4 (Glycine max GST Tau 4-4) complexed with GSH was determined by the molecular replacement method at 2.7 A (1 A=0.1 nm) resolution. The bound GSH is located in a region formed by the beginning of alpha-helices H1, H2 and H3 in the N-terminal domain of the enzyme. Significant differences in the G-site (GSH-binding site) as compared with the structure determined in complex with Nb-GSH [S-(p-nitrobenzyl)-glutathione] were found. These differences were identified in the hydrogen-bonding and electrostatic interaction pattern and, consequently, GSH was found bound in two different conformations. In one subunit, the enzyme forms a complex with the ionized form of GSH, whereas in the other subunit it can form a complex with the non-ionized form. However, only the ionized form of GSH may form a productive and catalytically competent complex. Furthermore, a comparison of the GSH-bound structure with the Nb-GSH-bound structure shows a significant movement of the upper part of alpha-helix H4 and the C-terminal. This indicates an intrasubunit modulation between the G-site and the H-site (electrophile-binding site), suggesting that the enzyme recognizes the xenobiotic substrates by an induced-fit mechanism. The reorganization of Arg111 and Tyr107 upon xenobiotic substrate binding appears to govern the intrasubunit structural communication between the G- and H-site and the binding of GSH. The structural observations were further verified by steady-state kinetic analysis and site-directed mutagenesis studies.

  15. Recombinant human dihydroxyacetonephosphate acyl-transferase characterization as an integral monotopic membrane protein.

    Science.gov (United States)

    Piano, Valentina; Nenci, Simone; Magnani, Francesca; Aliverti, Alessandro; Mattevi, Andrea

    2016-12-02

    Although the precise functions of ether phospholipids are still poorly understood, significant alterations in their physiological levels are associated either to inherited disorders or to aggressive metastatic cancer. The essential precursor, alkyl-dihydroxyacetone phosphate (DHAP), for all ether phospholipids species is synthetized in two consecutive reactions performed by two enzymes sitting on the inner side of the peroxisomal membrane. Here, we report the characterization of the recombinant human DHAP acyl-transferase, which performs the first step in alkyl-DHAP synthesis. By exploring several expression systems and designing a number of constructs, we were able to purify the enzyme in its active form and we found that it is tightly bound to the membrane through the N-terminal residues. Copyright © 2016 The Authors. Published by Elsevier Inc. All rights reserved.

  16. Urinary gamma-glutamyl transferase as an indicator of acute nephrotoxicity in rats

    Energy Technology Data Exchange (ETDEWEB)

    Dierickx, P.J.

    1981-06-01

    A series of nephrotoxic compounds dissolved in 0.9% NaCl was given to groups of five male Wistar rats in a single i.p. injection. Mercuric acetate and mercuric trifluoroacetate at 1 mg Hg/kg induced a sharp increase in urinary gamma-glutamyl transferase (GGT) activity on day 1, followed by a decrease below control values on day 3. Sodium ethylmercurithiosalicylate induced a relatively small urinary GGT increase, explained by its low Hg-bioavailability. An increased urinary GGT activity was noted after treatment with the aminoglycoside antibiotics kanamycin, neomycin, paramomycin, and streptomycin, ammonium fluoride, potassium bichromate, sodium tetrathionate, and cis-diamminedichloroplatinum. This was lower than for the mercury compounds, but clearly different from the controls. The urinary GGT increase was an acute phenomenon. It is concluded that the measurement of urinary GGT can be used as an indicator of acute nephrotoxicity.

  17. Atypical features of a Ure2p glutathione transferase from Phanerochaete chrysosporium.

    Science.gov (United States)

    Thuillier, Anne; Roret, Thomas; Favier, Frédérique; Gelhaye, Eric; Jacquot, Jean-Pierre; Didierjean, Claude; Morel-Rouhier, Mélanie

    2013-07-11

    Glutathione transferases (GSTs) are known to transfer glutathione onto small hydrophobic molecules in detoxification reactions. The GST Ure2pB1 from Phanerochaete chrysosporium exhibits atypical features, i.e. the presence of two glutathione binding sites and a high affinity towards oxidized glutathione. Moreover, PcUre2pB1 is able to efficiently deglutathionylate GS-phenacylacetophenone. Catalysis is not mediated by the cysteines of the protein but rather by the one of glutathione and an asparagine residue plays a key role in glutathione stabilization. Interestingly PcUre2pB1 interacts in vitro with a GST of the omega class. These properties are discussed in the physiological context of wood degrading fungi.

  18. Pharmacogenetics of azathioprine in inflammatory bowel disease: a role for glutathione-S-transferase?

    Science.gov (United States)

    Stocco, Gabriele; Pelin, Marco; Franca, Raffaella; De Iudicibus, Sara; Cuzzoni, Eva; Favretto, Diego; Martelossi, Stefano; Ventura, Alessandro; Decorti, Giuliana

    2014-04-01

    Azathioprine is a purine antimetabolite drug commonly used to treat inflammatory bowel disease (IBD). In vivo it is active after reaction with reduced glutathione (GSH) and conversion to mercaptopurine. Although this reaction may occur spontaneously, the presence of isoforms M and A of the enzyme glutathione-S-transferase (GST) may increase its speed. Indeed, in pediatric patients with IBD, deletion of GST-M1, which determines reduced enzymatic activity, was recently associated with reduced sensitivity to azathioprine and reduced production of azathioprine active metabolites. In addition to increase the activation of azathioprine to mercaptopurine, GSTs may contribute to azathioprine effects even by modulating GSH consumption, oxidative stress and apoptosis. Therefore, genetic polymorphisms in genes for GSTs may be useful to predict response to azathioprine even if more in vitro and clinical validation studies are needed.

  19. Glutathione-binding site of a bombyx mori theta-class glutathione transferase.

    Directory of Open Access Journals (Sweden)

    M D Tofazzal Hossain

    Full Text Available The glutathione transferase (GST superfamily plays key roles in the detoxification of various xenobiotics. Here, we report the isolation and characterization of a silkworm protein belonging to a previously reported theta-class GST family. The enzyme (bmGSTT catalyzes the reaction of glutathione with 1-chloro-2,4-dinitrobenzene, 1,2-epoxy-3-(4-nitrophenoxy-propane, and 4-nitrophenethyl bromide. Mutagenesis of highly conserved residues in the catalytic site revealed that Glu66 and Ser67 are important for enzymatic function. These results provide insights into the catalysis of glutathione conjugation in silkworm by bmGSTT and into the metabolism of exogenous chemical agents.

  20. Irreversible Inhibition of Glutathione S-Transferase by Phenethyl Isothiocyanate (PEITC), a Dietary Cancer Chemopreventive Phytochemical

    Science.gov (United States)

    Kumari, Vandana; Dyba, Marzena A.; Holland, Ryan J.; Liang, Yu-He; Singh, Shivendra V.

    2016-01-01

    Dietary isothiocyanates abundant as glucosinolate precursors in many edible cruciferous vegetables are effective for prevention of cancer in chemically-induced and transgenic rodent models. Some of these agents, including phenethyl isothiocyanate (PEITC), have already advanced to clinical investigations. The primary route of isothiocyanate metabolism is its conjugation with glutathione (GSH), a reaction catalyzed by glutathione S-transferase (GST). The pi class GST of subunit type 1 (hGSTP1) is much more effective than the alpha class GST of subunit type 1 (hGSTA1) in catalyzing the conjugation. Here, we report the crystal structures of hGSTP1 and hGSTA1 each in complex with the GSH adduct of PEITC. We find that PEITC also covalently modifies the cysteine side chains of GST, which irreversibly inhibits enzymatic activity. PMID:27684484

  1. Diversification of fungal specific class a glutathione transferases in saprotrophic fungi.

    Directory of Open Access Journals (Sweden)

    Yann Mathieu

    Full Text Available Glutathione transferases (GSTs form a superfamily of multifunctional proteins with essential roles in cellular detoxification processes and endogenous metabolism. The distribution of fungal-specific class A GSTs was investigated in saprotrophic fungi revealing a recent diversification within this class. Biochemical characterization of eight GSTFuA isoforms from Phanerochaete chrysosporium and Coprinus cinereus demonstrated functional diversity in saprotrophic fungi. The three-dimensional structures of three P. chrysosporium isoforms feature structural differences explaining the functional diversity of these enzymes. Competition experiments between fluorescent probes, and various molecules, showed that these GSTs function as ligandins with various small aromatic compounds, derived from lignin degradation or not, at a L-site overlapping the glutathione binding pocket. By combining genomic data with structural and biochemical determinations, we propose that this class of GST has evolved in response to environmental constraints induced by wood chemistry.

  2. Chemical proteomics with sulfonyl fluoride probes reveals selective labeling of functional tyrosines in glutathione transferases.

    Science.gov (United States)

    Gu, Christian; Shannon, D Alexander; Colby, Tom; Wang, Zheming; Shabab, Mohammed; Kumari, Selva; Villamor, Joji Grace; McLaughlin, Christopher J; Weerapana, Eranthie; Kaiser, Markus; Cravatt, Benjamin F; van der Hoorn, Renier A L

    2013-04-18

    Chemical probes have great potential for identifying functional residues in proteins in crude proteomes. Here we studied labeling sites of chemical probes based on sulfonyl fluorides (SFs) on plant and animal proteomes. Besides serine proteases and many other proteins, SF-based probes label Tyr residues in glutathione transferases (GSTs). The labeled GSTs represent four different GST classes that share less than 30% sequence identity. The targeted Tyr residues are located at similar positions in the promiscuous substrate binding site and are essential for GST function. The high selectivity of SF-based probes for functional Tyr residues in GSTs illustrates how these probes can be used for functional studies of GSTs and other proteins in crude proteomes.

  3. Crystallization and preliminary X-ray analysis of glutathione transferases from cyanobacteria

    Energy Technology Data Exchange (ETDEWEB)

    Feil, Susanne C.; Tang, Julian; Hansen, Guido; Gorman, Michael A.; Wiktelius, Eric; Stenberg, Gun; Parker, Michael W.; (SVIMR-A); (Uppsala)

    2009-05-08

    Glutathione S-transferases (GSTs) are a group of multifunctional enzymes that are found in animals, plants and microorganisms. Their primary function is to remove toxins derived from exogenous sources or the products of metabolism from the cell. Mammalian GSTs have been extensively studied, in contrast to bacterial GSTs which have received relatively scant attention. A new class of GSTs called Chi has recently been identified in cyanobacteria. Chi GSTs exhibit a high glutathionylation activity towards isothiocyanates, compounds that are normally found in plants. Here, the crystallization of two GSTs are presented: TeGST produced by Thermosynechococcus elongates BP-1 and SeGST from Synechococcus elongates PCC 6301. Both enzymes formed crystals that diffracted to high resolution and appeared to be suitable for further X-ray diffraction studies. The structures of these GSTs may shed further light on the evolution of GST catalytic activity and in particular why these enzymes possess catalytic activity towards plant antimicrobial compounds.

  4. Glutathione transferases immobilized on nanoporous alumina: flow system kinetics, screening, and stability.

    Science.gov (United States)

    Kjellander, Marcus; Mazari, Aslam M A; Boman, Mats; Mannervik, Bengt; Johansson, Gunnar

    2014-02-01

    The previously uncharacterized Drosophila melanogaster Epsilon-class glutathione transferases E6 and E7 were immobilized on nanoporous alumina. The nanoporous anodized alumina membranes were derivatized with 3-aminopropyl-triethoxysilane, and the amino groups were activated with carbonyldiimidazole to allow coupling of the enzymes via ε-amino groups. Kinetic analyses of the immobilized enzymes were carried out in a circulating flow system using CDNB (1-chloro-2,4-dinitrobenzene) as substrate, followed by specificity screening with alternative substrates. A good correlation was observed between the substrate screening data for immobilized enzyme and corresponding data for the enzyme in solution. A limited kinetic study was also carried out on immobilized human GST S1-1 (also known as hematopoietic prostaglandin D synthase). The stability of the immobilized enzymes was virtually identical to that of enzymes in solution, and no leakage of enzyme from the matrix could be observed.

  5. Theoretical Study on GSH Activation Mechanism of a New Type of Glutathione Transferase Gtt2

    Institute of Scientific and Technical Information of China (English)

    LI Xue; WU Yun-jian; LI Zhuo; CHU Wen-ting; ZHANG Hong-xing; ZHENG Qing-chuan

    2012-01-01

    Glutathione transferases(GSTs) play an important role in the detoxification of xenobiotic/endobiotic toxic compounds.The a-,π-,and μ-classes of cytosolic GSTs have been studied extensively,while Gtt2 from Saccharomyces cerevisiae,a novel atypical GST,is still poorly understood.In the present study,we investigated the glutathione(GSH) activation mechanism of Gtt2 using the density functional theory(DFT) with the hybrid functional B3LYP.The computational results show that a water molecule could assist a proton transfer between the GSH thiol and the N atom of His133.The energy barrier of proton transfer is 46.0 kJ/mol.The GSH activation mechanism and the characteristics of active site are different from those of classic cytosolic GSTs.

  6. Glutathione transferases are structural and functional outliers in the thioredoxin fold.

    Science.gov (United States)

    Atkinson, Holly J; Babbitt, Patricia C

    2009-11-24

    Glutathione transferases (GSTs) are ubiquitous scavengers of toxic compounds that fall, structurally and functionally, within the thioredoxin fold suprafamily. The fundamental catalytic capability of GSTs is catalysis of the nucleophilic addition or substitution of glutathione at electrophilic centers in a wide range of small electrophilic compounds. While specific GSTs have been studied in detail, little else is known about the structural and functional relationships between different groupings of GSTs. Through a global analysis of sequence and structural similarity, it was determined that variation in the binding of glutathione between the two major subgroups of cytosolic (soluble) GSTs results in a different mode of glutathione activation. Additionally, the convergent features of glutathione binding between cytosolic GSTs and mitochondrial GST kappa are described. The identification of these structural and functional themes helps to illuminate some of the fundamental contributions of the thioredoxin fold to catalysis in the GSTs and clarify how the thioredoxin fold can be modified to enable new functions.

  7. Diversification of fungal specific class a glutathione transferases in saprotrophic fungi.

    Science.gov (United States)

    Mathieu, Yann; Prosper, Pascalita; Favier, Frédérique; Harvengt, Luc; Didierjean, Claude; Jacquot, Jean-Pierre; Morel-Rouhier, Mélanie; Gelhaye, Eric

    2013-01-01

    Glutathione transferases (GSTs) form a superfamily of multifunctional proteins with essential roles in cellular detoxification processes and endogenous metabolism. The distribution of fungal-specific class A GSTs was investigated in saprotrophic fungi revealing a recent diversification within this class. Biochemical characterization of eight GSTFuA isoforms from Phanerochaete chrysosporium and Coprinus cinereus demonstrated functional diversity in saprotrophic fungi. The three-dimensional structures of three P. chrysosporium isoforms feature structural differences explaining the functional diversity of these enzymes. Competition experiments between fluorescent probes, and various molecules, showed that these GSTs function as ligandins with various small aromatic compounds, derived from lignin degradation or not, at a L-site overlapping the glutathione binding pocket. By combining genomic data with structural and biochemical determinations, we propose that this class of GST has evolved in response to environmental constraints induced by wood chemistry.

  8. Response of Glutathione and Glutathione S-transferase in Rice Seedlings Exposed to Cadmium Stress

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chun-hua; GE Ying

    2008-01-01

    A hydroponic culture experiment was done to investigate the effect of Cd stress on glutathione content(GSH)and glutathione S-transferase(GST,EC 2.5.1.18)activity in rice seedlings.The rice growth was severely inhibited when Cd level in the solution was higher than 10 mg/L.In rice shoots,GSH content and GST activity increased with the increasing Cd level,while in roots,GST was obviously inhibited by Cd treatments.Compared with shoots,the rice roots had higher GSH content and GST activity,indicating the ability of Cd detoxification was much higher in roots than in shoots.There was a significant correlation between Cd level and GSH content or GST activity,suggesting that both parameters may be used as biomarkers of Cd stress in rice.

  9. Response of Glutathione and Glutathione S-transferase in Rice Seedlings Exposed to Cadmium Stress

    Directory of Open Access Journals (Sweden)

    Chun-hua ZHANG

    2008-03-01

    Full Text Available A hydroponic culture experiment was done to investigate the effect of Cd stress on glutathione content (GSH and glutathione S-transferase (GST, EC 2.5.1.18 activity in rice seedlings. The rice growth was severely inhibited when Cd level in the solution was higher than 10 mg/L. In rice shoots, GSH content and GST activity increased with the increasing Cd level, while in roots, GST was obviously inhibited by Cd treatments. Compared with shoots, the rice roots had higher GSH content and GST activity, indicating the ability of Cd detoxification was much higher in roots than in shoots. There was a significant correlation between Cd level and GSH content or GST activity, suggesting that both parameters may be used as biomarkers of Cd stress in rice.

  10. The role of glutathione S-transferase and claudin-1 gene polymorphisms in contact sensitization

    DEFF Research Database (Denmark)

    Ross-Hansen, K; Linneberg, A; Johansen, J D

    2013-01-01

    BACKGROUND: Contact sensitization is frequent in the general population and arises from excessive or repeated skin exposure to chemicals and metals. However, little is known about its genetic susceptibility. OBJECTIVES: To determine the role of polymorphisms of glutathione S-transferase (GST) genes...... with the minor allele of CLDN1 SNP rs9290927 (P(trend)=0·013). For CLDN1 rs17501010, contact sensitization to organic compounds was associated with the major allele (P(trend)=0·031). The risk pattern was also identified for self-reported nickel dermatitis (P(trend)=0·011). The fragrance sensitization prevalence......, respectively, with nickel contact sensitization in individuals without ear piercings, contact sensitization to fragrances, and with both organic compounds and nickel contact dermatitis. We could not find associations between GST gene polymorphisms and contact sensitization. FLG mutations did not affect...

  11. Glutathione S-transferases of 28kDa as major vaccine candidates against schistosomiasis

    Directory of Open Access Journals (Sweden)

    Gilles Riveau

    1998-01-01

    Full Text Available For the development of vaccine strategies to generate efficient protection against chronic infections such as parasitic diseases, and more precisely schistosomiasis, controlling pathology could be more relevant than controlling the infection itself. Such strategies, motivated by the need for a cost-effective complement to existing control measures, should focus on parasite molecules involved in fecundity, because in metazoan parasite infections pathology is usually linked to the output of viable eggs. In numerous animal models, vaccination with glutathione S-transferases of 28kDa has been shown to generate an immune response strongly limiting the worm fecundity, in addition to the reduction of the parasite burden. Recent data on acquired immunity directed to 28GST in infected human populations, and new development to draw adapted vaccine formulations, are presented.

  12. Vitamin C levels in blood are influenced by polymorphisms in glutathione S-transferases.

    Science.gov (United States)

    Horska, Alexandra; Mislanova, Csilla; Bonassi, Stefano; Ceppi, Marcello; Volkovova, Katarina; Dusinska, Maria

    2011-09-01

    Glutathione S-transferases (GSTs) are intimately involved in combating oxidative stress and in detoxifying xenobiotics. Our objective was to examine possible interactions between polymorphisms in GST genes and plasma vitamin C, tocopherols and carotenoids in 149 reference subjects and 239 subjects occupationally exposed to mineral fibres (asbestos, rock wool, glass fibre), agents that induce oxidative stress. Deletion of GSTM1 and GSTT1, and substitution 105Ile/Val in GSTP1 genes were determined by PCR, antioxidants in plasma were measured by HPLC. Tocopherols and carotenoids were affected by age, sex, smoking, occupational exposure to fibres, but not by GST polymorphisms. Vitamin C level was influenced by sex, smoking and occupational exposure. Subjects with deletion of GST had lower vitamin C levels compared with subjects carrying the functional gene variant. Vitamin C levels varied according to GSTM1 polymorphism in the whole group (p makeup and in those exposed to oxidative stress.

  13. Rab geranylgeranyl transferase β subunit is essential for male fertility and tip growth in Arabidopsis.

    Science.gov (United States)

    Gutkowska, Malgorzata; Wnuk, Marta; Nowakowska, Julita; Lichocka, Malgorzata; Stronkowski, Michal M; Swiezewska, Ewa

    2015-01-01

    Rab proteins, key players in vesicular transport in all eukaryotic cells, are post-translationally modified by lipid moieties. Two geranylgeranyl groups are attached to the Rab protein by the heterodimeric enzyme Rab geranylgeranyl transferase (RGT) αβ. Partial impairment in this enzyme activity in Arabidopsis, by disruption of the AtRGTB1 gene, is known to influence plant stature and disturb gravitropic and light responses. Here it is shown that mutations in each of the RGTB genes cause a tip growth defect, visible as root hair and pollen tube deformations. Moreover, FM 1-43 styryl dye endocytosis and recycling are affected in the mutant root hairs. Finally, it is demonstrated that the double mutant, with both AtRGTB genes disrupted, is non-viable due to absolute male sterility. Doubly mutated pollen is shrunken, has an abnormal exine structure, and shows strong disorganization of internal membranes, particularly of the endoplasmic reticulum system.

  14. Biochemical properties of an omega-class glutathione S-transferase of the silkmoth, Bombyx mori.

    Science.gov (United States)

    Yamamoto, Kohji; Nagaoka, Sumiharu; Banno, Yutaka; Aso, Yoichi

    2009-05-01

    A cDNA encoding an omega-class glutathione S-transferase of the silkmoth, Bombyx mori (bmGSTO), was cloned by reverse transcriptase-polymerase chain reaction. The resulting clone was sequenced and deduced for amino acid sequence, which revealed 40, 40, and 39% identities to omega-class GSTs from human, pig, and mouse, respectively. A recombinant protein (rbmGSTO) was functionally overexpressed in Escherichia coli cells in a soluble form and purified to homogeneity. rbmGSTO was able to catalyze the biotranslation of glutathione with 1-chloro-2,4-dinitrobenzene, a model substrate for GST, as well as with 4-hydroxynonenal, a product of lipid peroxidation. This enzyme was shown to have high affinity for organophosphorus insecticide and was present abundantly in silkmoth strain exhibiting fenitrothion resistance. These results indicate that bmGSTO could be involved in the increase in level of insecticide resistance for lepidopteran insects.

  15. Molybdenum and tungsten oxygen transferases--and functional diversity within a common active site motif.

    Science.gov (United States)

    Pushie, M Jake; Cotelesage, Julien J; George, Graham N

    2014-01-01

    Molybdenum and tungsten are the only second and third-row transition elements with a known function in living organisms. The molybdenum and tungsten enzymes show common structural features, with the metal being bound by a pyranopterin-dithiolene cofactor called molybdopterin. They catalyze a variety of oxygen transferase reactions coupled with two-electron redox chemistry in which the metal cycles between the +6 and +4 oxidation states usually with water, either product or substrate, providing the oxygen. The functional roles filled by the molybdenum and tungsten enzymes are diverse; for example, they play essential roles in microbial respiration, in the uptake of nitrogen in green plants, and in human health. Together, the enzymes form a superfamily which is among the most prevalent known, being found in all kingdoms of life. This review discusses what is known of the active site structures and the mechanisms, together with some recent insights into the evolution of these important enzyme systems.

  16. Bimaxillary Oral Focal Mucinosis.

    Science.gov (United States)

    Yadav, Sunil; Malik, Sunita; Mittal, Hitesh Chander; Singh, Gurdarshan; Kamra, Hemlata

    2016-10-01

    Oral focal mucinosis is considered as oral counterpart of cutaneous focal mucinosis. The preoperative diagnosis of mucinosis is almost impossible because of its rarity and clinical similarity to other lesions of various etiologies. The histological diagnosis of oral mucinosis is important to better understand the etiopathogenesis, treatment modalities, and any recurrence of the lesion besides differentiating from the other soft tissue lesions.The purpose of this paper is to report the first case of bimaxillary involvement with dome-shaped elevated, rounded, asymptomatic, normally colored swelling in left posterior palatal mucosa and left mandibular posterior region in a 25-year old woman who was diagnosed as oral focal mucinosis histopathologically.

  17. Chrysomya Bezziana oral myiasis

    Directory of Open Access Journals (Sweden)

    G S Vijay Kumar

    2011-01-01

    Full Text Available Myiasis is an opportunistic infestation of human and vertebrate animals with dipterous larvae. Oral myiasis is a rare condition associated with poor oral hygiene, mental disability, halitosis and other conditions. We present a case report of an adult mentally challenged woman with extensive necrotic oral lesion burrowing into the hard palate through which three live maggots (larvae were seen emerging out. The larvae were removed using forceps and the patient was treated with oral ivermectin. The maggots were identified as larvae of the Chrysomya bezziana fly.

  18. Oral microbiota and cancer

    Directory of Open Access Journals (Sweden)

    Jukka H. Meurman

    2010-08-01

    Full Text Available Inflammation caused by infections may be the most important preventable cause of cancer in general. However, in the oral cavity the role of microbiota in carcinogenesis is not known. Microbial populations on mouth mucosa differ between healthy and malignant sites and certain oral bacterial species have been linked with malignancies but the evidence is still weak in this respect. Nevertheless, oral microorganisms inevitably up-regulate cytokines and other inflammatory mediators that affect the complex metabolic pathways and may thus be involved in carcinogenesis. Poor oral health associates statistically with prevalence of many types of cancer, such as pancreatic and gastrointestinal cancer. Furthermore, several oral micro-organisms are capable of converting alcohol to carcinogenic acetaldehyde which also may partly explain the known association between heavy drinking, smoking, poor oral health and the prevalence of oral and upper gastrointestinal cancer. A different problem is the cancer treatment-caused alterations in oral microbiota which may lead to the emergence of potential pathogens and subsequent other systemic health problems to the patients. Hence clinical guidelines and recommendations have been presented to control oral microbiota in patients with malignant disease, but also in this area the scientific evidence is weak. More controlled studies are needed for further conclusion.

  19. Oral Cancer Exam

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  20. Oral Cancer Exam

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  1. Towards understanding oral health.

    Science.gov (United States)

    Zaura, Egija; ten Cate, Jacob M

    2015-01-01

    During the last century, dental research has focused on unraveling the mechanisms behind various oral pathologies, while oral health was typically described as the mere absence of oral diseases. The term 'oral microbial homeostasis' is used to describe the capacity of the oral ecosystem to maintain microbial community stability in health. However, the oral ecosystem itself is not stable: throughout life an individual undergoes multiple physiological changes while progressing through infancy, childhood, adolescence, adulthood and old age. Recent discussions on the definition of general health have led to the proposal that health is the ability of the individual to adapt to physiological changes, a condition known as allostasis. In this paper the allostasis principle is applied to the oral ecosystem. The multidimensionality of the host factors contributing to allostasis in the oral cavity is illustrated with an example on changes occurring in puberty. The complex phenomenon of oral health and the processes that prevent the ecosystem from collapsing during allostatic changes in the entire body are far from being understood. As yet individual components (e.g. hard tissues, microbiome, saliva, host response) have been investigated, while only by consolidating these and assessing their multidimensional interactions should we be able to obtain a comprehensive understanding of the ecosystem, which in turn could serve to develop rational schemes to maintain health. Adapting such a 'system approach' comes with major practical challenges for the entire research field and will require vast resources and large-scale multidisciplinary collaborations.

  2. A glutathione transferase from Agrobacterium tumefaciens reveals a novel class of bacterial GST superfamily.

    Science.gov (United States)

    Skopelitou, Katholiki; Dhavala, Prathusha; Papageorgiou, Anastassios C; Labrou, Nikolaos E

    2012-01-01

    In the present work, we report a novel class of glutathione transferases (GSTs) originated from the pathogenic soil bacterium Agrobacterium tumefaciens C58, with structural and catalytic properties not observed previously in prokaryotic and eukaryotic GST isoenzymes. A GST-like sequence from A. tumefaciens C58 (Atu3701) with low similarity to other characterized GST family of enzymes was identified. Phylogenetic analysis showed that it belongs to a distinct GST class not previously described and restricted only in soil bacteria, called the Eta class (H). This enzyme (designated as AtuGSTH1-1) was cloned and expressed in E. coli and its structural and catalytic properties were investigated. Functional analysis showed that AtuGSTH1-1 exhibits significant transferase activity against the common substrates aryl halides, as well as very high peroxidase activity towards organic hydroperoxides. The crystal structure of AtuGSTH1-1 was determined at 1.4 Å resolution in complex with S-(p-nitrobenzyl)-glutathione (Nb-GSH). Although AtuGSTH1-1 adopts the canonical GST fold, sequence and structural characteristics distinct from previously characterized GSTs were identified. The absence of the classic catalytic essential residues (Tyr, Ser, Cys) distinguishes AtuGSTH1-1 from all other cytosolic GSTs of known structure and function. Site-directed mutagenesis showed that instead of the classic catalytic residues, an Arg residue (Arg34), an electron-sharing network, and a bridge of a network of water molecules may form the basis of the catalytic mechanism. Comparative sequence analysis, structural information, and site-directed mutagenesis in combination with kinetic analysis showed that Phe22, Ser25, and Arg187 are additional important residues for the enzyme's catalytic efficiency and specificity.

  3. A glutathione transferase from Agrobacterium tumefaciens reveals a novel class of bacterial GST superfamily.

    Directory of Open Access Journals (Sweden)

    Katholiki Skopelitou

    Full Text Available In the present work, we report a novel class of glutathione transferases (GSTs originated from the pathogenic soil bacterium Agrobacterium tumefaciens C58, with structural and catalytic properties not observed previously in prokaryotic and eukaryotic GST isoenzymes. A GST-like sequence from A. tumefaciens C58 (Atu3701 with low similarity to other characterized GST family of enzymes was identified. Phylogenetic analysis showed that it belongs to a distinct GST class not previously described and restricted only in soil bacteria, called the Eta class (H. This enzyme (designated as AtuGSTH1-1 was cloned and expressed in E. coli and its structural and catalytic properties were investigated. Functional analysis showed that AtuGSTH1-1 exhibits significant transferase activity against the common substrates aryl halides, as well as very high peroxidase activity towards organic hydroperoxides. The crystal structure of AtuGSTH1-1 was determined at 1.4 Å resolution in complex with S-(p-nitrobenzyl-glutathione (Nb-GSH. Although AtuGSTH1-1 adopts the canonical GST fold, sequence and structural characteristics distinct from previously characterized GSTs were identified. The absence of the classic catalytic essential residues (Tyr, Ser, Cys distinguishes AtuGSTH1-1 from all other cytosolic GSTs of known structure and function. Site-directed mutagenesis showed that instead of the classic catalytic residues, an Arg residue (Arg34, an electron-sharing network, and a bridge of a network of water molecules may form the basis of the catalytic mechanism. Comparative sequence analysis, structural information, and site-directed mutagenesis in combination with kinetic analysis showed that Phe22, Ser25, and Arg187 are additional important residues for the enzyme's catalytic efficiency and specificity.

  4. Serum glutathione transferase does not respond to indole-3-carbinol: A pilot study

    Directory of Open Access Journals (Sweden)

    Daniel R McGrath

    2010-05-01

    Full Text Available Daniel R McGrath1, Hamid Frydoonfar2, Joshua J Hunt3, Chris J Dunkley3, Allan D Spigelman41Ipswich Hospital, Ipswich, UK; 2Hunter Pathology Service, New South Wales; 3Royal Newcastle Centre, Newcastle; 4St Vincent’s Clinical School, Sydney, AustraliaBackground: Despite the well recognized protective effect of cruciferous vegetables against various cancers, including human colorectal cancers, little is known about how this effect is conferred. It is thought that some phytochemicals found only in these vegetables confer the protection. These compounds include the glucosinolates, of which indole-3-carbinol is one. They are known to induce carcinogen-metabolizing (phase II enzymes, including the glutathione S-transferase (GST family. Other effects in humans are not well documented. We wished to assess the effect of indole-3-carbinol on GST enzymes.Methods: We carried out a placebo-controlled human volunteer study. All patients were given 400 mg daily of indole-3-carbinol for three months, followed by placebo. Serum samples were tested for the GSTM1 genotype by polymerase chain reaction. Serum GST levels were assessed using enzyme-linked immunosorbent assay and Western Blot methodologies.Results: Forty-nine volunteers completed the study. GSTM1 genotypes were obtained for all but two volunteers. A slightly greater proportion of volunteers were GSTM1-positive, in keeping with the general population. GST was detected in all patients. Total GST level was not affected by indole-3-carbinol dosing compared with placebo. Although not statistically significant, the GSTM1 genotype affected the serum GST level response to indole-3-carbinol.Conclusion: Indole-3-carbinol does not alter total serum GST levels during prolonged dosing.Keywords: pilot study, colorectal cancer, glutathione transferase, human, indole-3-carbinol

  5. Transferase activity function and system development process are critical in cattle embryo development.

    Science.gov (United States)

    Adams, Heather A; Southey, Bruce R; Everts, Robin E; Marjani, Sadie L; Tian, Cindy X; Lewin, Harris A; Rodriguez-Zas, Sandra L

    2011-03-01

    Microarray gene expression experiments often consider specific developmental stages, tissue sources, or reproductive technologies. This focus hinders the understanding of the cattle embryo transcriptome. To address this, four microarray experiments encompassing three developmental stages (7, 25, 280 days), two tissue sources (embryonic or extra-embryonic), and two reproductive technologies (artificial insemination or AI and somatic cell nuclear transfer or NT) were combined using two sets of meta-analyses. The first set of meta-analyses uncovered 434 genes differentially expressed between AI and NT (regardless of stage or source) that were not detected by the individual-experiment analyses. The molecular function of transferase activity was enriched among these genes that included ECE2, SLC22A1, and a gene similar to CAMK2D. Gene POLG2 was over-expressed in AI versus NT 7-day embryos and was under-expressed in AI versus NT 25-day embryos. Gene HAND2 was over-expressed in AI versus NT extra-embryonic samples at 280 days yet under-expressed in AI versus NT embryonic samples at 7 days. The second set of meta-analyses uncovered enrichment of system, organ, and anatomical structure development among the genes differentially expressed between 7- and 25-day embryos from either reproductive technology. Genes PRDX1and SLC16A1 were over-expressed in 7- versus 25-day AI embryos and under-expressed in 7- versus 25-day NT embryos. Changes in stage were associated with high number of differentially expressed genes, followed by technology and source. Genes with transferase activity may hold a clue to the differences in efficiency between reproductive technologies.

  6. Catalysis of Silver catfish Major Hepatic Glutathione Transferase proceeds via rapid equilibrium sequential random Mechanism

    Directory of Open Access Journals (Sweden)

    Ayodele O. Kolawole

    2016-01-01

    Full Text Available Fish hepatic glutathione transferases are connected with the elimination of intracellular pollutants and detoxification of organic micro-pollutants in their aquatic ecosystem. The two-substrate steady state kinetic mechanism of Silver catfish (Synodontis eupterus major hepatic glutathione transferases purified to apparent homogeneity was explored. The enzyme was dimeric enzyme with a monomeric size of 25.6 kDa. Initial-velocity studies and Product inhibition patterns by methyl glutathione and chloride with respect to GSH-CDNB; GSH-ρ-nitrophenylacetate; and GSH-Ethacrynic acid all conforms to a rapid equilibrium sequential random Bi Bi kinetic mechanism rather than steady state sequential random Bi Bi kinetic. α was 2.96 ± 0.35 for the model. The pH profile of Vmax/KM (with saturating 1-chloro-2,4-dinitrobenzene and variable GSH concentrations showed apparent pKa value of 6.88 and 9.86. Inhibition studies as a function of inhibitor concentration show that the enzyme is a homodimer and near neutral GST. The enzyme poorly conjugates 4-hydroxylnonenal and cumene hydroperoxide and may not be involved in oxidative stress protection. The seGST is unique and overwhelmingly shows characteristics similar to those of homodimeric class Pi GSTs, as was indicated by its kinetic mechanism, substrate specificity and inhibition studies. The rate- limiting step, probably the product release, of the reaction is viscosity-dependent and is consequential if macro-viscosogen or micro-viscosogen.

  7. Selection of Arabidopsis mutants overexpressing genes driven by the promoter of an auxin-inducible glutathione S-transferase gene

    NARCIS (Netherlands)

    Kop, D.A.M. van der; Schuyer, M.; Pinas, J.E.; Zaal, B.J. van der; Hooykaas, P.J.J.

    1999-01-01

    Transgenic arabidopsis plants were isolated that contained a T-DNA construct in which the promoter of an auxin-inducible glutathione S-transferase (GST) gene from tobacco was fused to the kanamycin resistance (nptII) as well as to the β-glucuronidase (gusA) reporter gene. Subsequently, seeds were tr

  8. CT-GalNAc transferase overexpression in adult mice is associated with extrasynaptic utrophin in skeletal muscle fibres.

    Science.gov (United States)

    Durko, Margaret; Allen, Carol; Nalbantoglu, Josephine; Karpati, George

    2010-09-01

    Duchenne muscular dystrophy is a genetic muscle disease characterized by the absence of sub-sarcolemmal dystrophin that results in muscle fibre necrosis, progressive muscle wasting and is fatal. Numerous experimental studies with dystrophin-deficient mdx mice, an animal model for the disease, have demonstrated that extrasynaptic upregulation of utrophin, an analogue of dystrophin, can prevent muscle fibre deterioration and reduce or negate the dystrophic phenotype. A different approach for ectopic expression of utrophin relies on augmentation of CT-GalNAc transferase in muscle fibre. We investigated whether CT-GalNAc transferase overexpression in adult mice influence appearance of utrophin in the extrasynaptic sarcolemma. After electrotransfer of plasmid DNA carrying an expression cassette of CT-GalNAc transferase into tibialis anterior muscle of wild type and dystrophic mice, muscle sections were examined by immunofluorescence. CT-GalNAc transgene expression augmented sarcolemmal carbohydrate glycosylation and was accompanied by extrasynaptic utrophin. A 6-week time course study showed that the highest efficiency of utrophin overexpression in a plasmid harboured muscle fibres was 32.2% in CD-1 and 52% in mdx mice, 2 and 4 weeks after CT-GalNAc gene transfer, respectively. The study provides evidence that postnatal CT-GalNAc transferase overexpression stimulates utrophin upregulation that is inherently beneficial for muscle structure and strength restoration. Thus CT-GalNAc may provide an important therapeutic molecule for treatment of dystrophin deficiency in Duchenne muscular dystrophy.

  9. The glutathione-S-transferase Mu 1 null genotype modulates ozone-induced airway inflammation in humans*

    Science.gov (United States)

    Background: The Glutathione-S-Transferase Mu 1 null genotype has been reported to be a risk factor for acute respiratory disease associated with increases in ambient air ozone. Ozone is known to cause an immediate decrease in lung function and increased airway inflammation. Howev...

  10. A germline homozygote deletion of the glutathione-s-transferase Mu 1 gene predisposes to bladder cancer

    NARCIS (Netherlands)

    Mungan, N.A.; Aben, K.K.H.; Beeks, E.; Kampman, E.; Bunschoten, A.; Bussemakers, M.; Witjes, J.A.

    2000-01-01

    Introduction and Objectives: Numerous studies have shown smoking and specific occupational exposures to be risk factors for bladder cancer. The risk of bladder cancer may be modified by the activity of carcinogen metabolizing enzymes. The glutathione-S-transferase Mu1 enzyme (GSTM1) detoxifies

  11. Characterization of the hydrophobic substrate-binding site of the bacterial beta class glutathione transferase from Proteus mirabilis.

    Science.gov (United States)

    Federici, Luca; Masulli, Michele; Di Ilio, Carmine; Allocati, Nerino

    2010-09-01

    Since their discovery, bacterial glutathione (GSH)transferases have been characterized in terms of their ability to catalyse a variety of different reactions on a large set of toxic molecules of xenobiotic or endobiotic origin. Furthermore the contribution of different residues in the GSH-binding site to GSH activation has been extensively investigated. Little is known, however, about the contribution to catalysis and overall stability of single residues shaping the hydrophobic co-substrate binding site (H-site). Here we tackle this problem by site-directed mutagenesis of residues facing the H-site in the bacterial beta class GSH transferase from Proteus mirabilis. We investigate the behaviour of these mutants under a variety of conditions and analyse their activity against several co-substrates, representative of the different reactions catalyzed by bacterial GSH transferases. Our work shows that mutations at the H-site can be used to modulate activity at the level of the different catalytic mechanisms operating on the chosen substrates, each mutation showing a different fingerprint. This work paves the way for future studies aimed at improving the catalytic properties of beta class GSH transferases against selected substrates for bioremediation purposes.

  12. Transmutation of human glutathione transferase A2-2 with peroxidase activity into an efficient steroid isomerase.

    Science.gov (United States)

    Pettersson, Par L; Johansson, Ann-Sofie; Mannervik, Bengt

    2002-08-16

    A major goal in protein engineering is the tailor-making of enzymes for specified chemical reactions. Successful attempts have frequently been based on directed molecular evolution involving libraries of random mutants in which variants with desired properties were identified. For the engineering of enzymes with novel functions, it would be of great value if the necessary changes of the active site could be predicted and implemented. Such attempts based on the comparison of similar structures with different substrate selectivities have previously met with limited success. However, the present work shows that the knowledge-based redesign restricted to substrate-binding residues in human glutathione transferase A2-2 can introduce high steroid double-bond isomerase activity into the enzyme originally characterized by glutathione peroxidase activity. Both the catalytic center activity (k(cat)) and catalytic efficiency (k(cat)/K(m)) match the values of the naturally evolved glutathione transferase A3-3, the most active steroid isomerase known in human tissues. The substrate selectivity of the mutated glutathione transferase was changed 7000-fold by five point mutations. This example demonstrates the functional plasticity of the glutathione transferase scaffold as well as the potential of rational active-site directed mutagenesis as a complement to DNA shuffling and other stochastic methods for the redesign of proteins with novel functions.

  13. Function and phylogeny of bacterial butyryl-CoA:acetate transferases and their diversity in the proximal colon of swine

    Science.gov (United States)

    Studying the host-associated butyrate-producing bacterial community is important because butyrate is essential for colonic homeostasis and gut health. Previous research has identified the butyryl-coA:acetate transferase (2.3.8.3) as a the main gene for butyrate production in intestinal ecosystems; h...

  14. Systemic catechol-O-methyl transferase inhibition enables the D1 agonist radiotracer R-[11C]SKF 82957

    DEFF Research Database (Denmark)

    Palner, Mikael; McCormick, Patrick; Parkes, Jun

    2010-01-01

    R-[(11)C]-SKF 82957 is a high-affinity and potent dopamine D(1) receptor agonist radioligand, which gives rise to a brain-penetrant lipophilic metabolite. In this study, we demonstrate that systemic administration of catechol-O-methyl transferase (COMT) inhibitors blocks this metabolic pathway, f...

  15. Tet Proteins Connect the O-Linked N-acetylglucosamine Transferase Ogt to Chromatin in Embryonic Stem Cells

    DEFF Research Database (Denmark)

    Vella, Pietro; Scelfo, Andrea; Jammula, Sriganesh;

    2013-01-01

    O-linked N-acetylglucosamine (O-GlcNAc) transferase (Ogt) activity is essential for embryonic stem cell (ESC) viability and mouse development. Ogt is present both in the cytoplasm and the nucleus of different cell types and catalyzes serine and threonine glycosylation. We have characterized...

  16. The glutathione-S-transferase Mu 1 null genotype modulates ozone-induced airway inflammation in humans*

    Science.gov (United States)

    Background: The Glutathione-S-Transferase Mu 1 null genotype has been reported to be a risk factor for acute respiratory disease associated with increases in ambient air ozone. Ozone is known to cause an immediate decrease in lung function and increased airway inflammation. Howev...

  17. Molecular mimicry between cockroach and helminth glutathione S-transferases promotes cross-reactivity and cross-sensitization

    Science.gov (United States)

    The extensive similarities between helminth proteins and allergens are thought to contribute to helminth-driven allergic sensitization. We investigated the molecular and structural similarities between Bla g 5, a major glutathione-S transferase (GST) allergen of cockroaches, and the GST of Wucherer...

  18. The structure of the neisserial lipooligosaccharide phosphoethanolamine transferase A (LptA) required for resistance to polymyxin.

    Science.gov (United States)

    Wanty, Christopher; Anandan, Anandhi; Piek, Susannah; Walshe, James; Ganguly, Jhuma; Carlson, Russell W; Stubbs, Keith A; Kahler, Charlene M; Vrielink, Alice

    2013-09-23

    Gram-negative bacteria possess an outer membrane envelope consisting of an outer leaflet of lipopolysaccharides, also called endotoxins, which protect the pathogen from antimicrobial peptides and have multifaceted roles in virulence. Lipopolysaccharide consists of a glycan moiety attached to lipid A, embedded in the outer membrane. Modification of the lipid A headgroups by phosphoethanolamine (PEA) or 4-amino-arabinose residues increases resistance to the cationic cyclic polypeptide antibiotic, polymyxin. Lipid A PEA transferases are members of the YhjW/YjdB/YijP superfamily and usually consist of a transmembrane domain anchoring the enzyme to the periplasmic face of the cytoplasmic membrane attached to a soluble catalytic domain. The crystal structure of the soluble domain of the protein of the lipid A PEA transferase from Neisseria meningitidis has been determined crystallographically and refined to 1.4Å resolution. The structure reveals a core hydrolase fold similar to that of alkaline phosphatase. Loop regions in the structure differ, presumably to enable interaction with the membrane-localized substrates and to provide substrate specificity. A phosphorylated form of the putative nucleophile, Thr280, is observed. Metal ions present in the active site are coordinated to Thr280 and to residues conserved among the family of transferases. The structure reveals the protein components needed for the transferase chemistry; however, substrate-binding regions are not evident and are likely to reside in the transmembrane domain of the protein. © 2013 Elsevier Ltd. All rights reserved.

  19. Common genotypic polymorphisms in glutathione S-transferases in mild and severe falciparum malaria in Tanzanian children.

    NARCIS (Netherlands)

    Kavishe, R.A.; Bousema, T.; Shekalaghe, S.; Sauerwein, R.W.; Mosha, F.W.; Ven, A.J.A.M. van der; Russel, F.G.M.; Koenderink, J.B.

    2009-01-01

    Malaria infection induces oxidative stress in the host cells. Antioxidant enzymes such as glutathione S-transferases (GSTs) are responsible for fighting reactive oxygen species and reduction of oxidative stress. Common GST polymorphisms have been associated with susceptibility to different diseases

  20. Sarcoidosis: Oral and extra-oral manifestation

    Directory of Open Access Journals (Sweden)

    Sanjay Gupta

    2015-01-01

    Full Text Available Sarcoidosis is a multisystem granulomatous disease, which is usually associated with the formation of noncaseating granulomas in affected tissues and organs. It is mostly present with bilateral hilar lymphadenopathy, pulmonary infiltration, ocular, and cutaneous lesions. Oral manifestations of this disease are relatively rare. The present case report shows a 40-year-old male with lesions in the soft tissue of oral cavity (buccal mucosa, gingiva, and palate and a diagnosis of sarcoidosis was established following hematological, biochemical and pulmonary function tests, chest radiograph, and histopathological investigation.

  1. Shared Oral Care

    DEFF Research Database (Denmark)

    Hede, Børge; Elmelund Poulsen,, Johan; Christophersen, Rasmus

    2014-01-01

    Shared Oral Care - Forebyggelse af orale sygdomme på plejecentre Introduktion og formål: Mangelfuld mundhygiejne hos plejekrævende ældre er et alment og veldokumenteret sundhedsproblem, der kan føre til massiv udvikling af tandsygdomme, og som yderligere kan være medvirkende årsag til alvorlige...

  2. Visual overview, oral detail

    DEFF Research Database (Denmark)

    Hertzum, Morten; Simonsen, Jesper

    2015-01-01

    and with the coordinating nurse, who is the main keeper of the whiteboard. On the basis of observations, we find that coordination is accomplished through a highly intertwined process of technologically mediated visual overview combined with orally communicated details. The oral details serve to clarify and elaborate...

  3. Oral Cancer Exam

    Medline Plus

    Full Text Available ... Decay See All Oral Complications of Systemic Diseases Cancer Treatment Developmental Disabilities Diabetes Heart Disease HIV/AIDS See ... this brochure includes information on symptoms, diagnosis, and treatment of oral cancer, along with definitions of selected medical terms and ...

  4. Oral Microbiology and Immunology

    DEFF Research Database (Denmark)

    Dahlén, Gunnar; Fiehn, Nils-Erik; Olsen, Ingar

    , dental assistants and trainees may find it a useful source of reference. The contents are based on general microbiology and immunology. Oral microbiology is given particular attention, with examples relevant to oral infectious diseases. Each chapter opens with a relatively short pre-reading section...

  5. Epilepsy and oral care.

    Science.gov (United States)

    Fiske, Janice; Boyle, Carole

    2002-05-01

    Epilepsy is a common symptom of an underlying neurological disorder. The seizures can take a variety of forms. Both the condition and its medical management can affect oral health. Prevention of oral disease and carefully planned dental treatment are essential to the well-being of people with epilepsy.

  6. Oral environment and cancer.

    Science.gov (United States)

    Kudo, Yasusei; Tada, Hidesuke; Fujiwara, Natsumi; Tada, Yoshiko; Tsunematsu, Takaaki; Miyake, Yoichiro; Ishimaru, Naozumi

    2016-01-01

    Cancer is now the leading cause of death in Japan. A rapid increase in cancer mortality is expected as Japan is facing a super-aged society. Many causes of cancer are known to be closely linked to life style factors, such as smoking, drinking, and diet. The oral environment is known to be involved in the pathogenesis and development of various diseases such as bronchitis, pneumonia, diabetes, heart disease, and dementia. Because the oral cavity acts as the bodily entrance for air and food, it is constantly exposed to foreign substances, including bacteria and viruses. A large number of bacteria are endemic to the oral cavity, and indigenous oral flora act to prevent the settlement of foreign bacteria. The oral environment is influenced by local factors, including dental plaque, tartar, teeth alignment, occlusion, an incompatible prosthesis, and bad lifestyle habits, and systemic factors, including smoking, consumption of alcohol, irregular lifestyle and eating habits, obesity, stress, hormones, and heredity. It has recently been revealed that the oral environment is associated with cancer. In particular, commensal bacteria in the oral cavity are involved in the development of cancer. Moreover, Candida, human papilloma virus and Epstein-Barr virus as well as commensal bacteria have been reported to be associated with the pathogenesis of cancer. In this review, we introduce recent findings of the correlation between the oral environment and cancer.

  7. Genomics of oral bacteria.

    Science.gov (United States)

    Duncan, Margaret J

    2003-01-01

    Advances in bacterial genetics came with the discovery of the genetic code, followed by the development of recombinant DNA technologies. Now the field is undergoing a new revolution because of investigators' ability to sequence and assemble complete bacterial genomes. Over 200 genome projects have been completed or are in progress, and the oral microbiology research community has benefited through projects for oral bacteria and their non-oral-pathogen relatives. This review describes features of several oral bacterial genomes, and emphasizes the themes of species relationships, comparative genomics, and lateral gene transfer. Genomics is having a broad impact on basic research in microbial pathogenesis, and will lead to new approaches in clinical research and therapeutics. The oral microbiota is a unique community especially suited for new challenges to sequence the metagenomes of microbial consortia, and the genomes of uncultivable bacteria.

  8. Oral syringe use survey.

    Science.gov (United States)

    Baldwin, J N; Wedemeyer, H F

    1980-09-01

    Use of oral syringes at children's and ASHP-accredited residency hospitals in the United States was surveyed. Questionnaires were mailed to 131 hospitals; 117 (89.3%) were returned. Of the responding hospitals, 54.5% of children's hospitals and 67.1% of residency hospitals used oral syringes. There was no definite preference for a particular brand or type (glass vs. plastic) of syringe. Patients who often required liquid dosage forms, including pediatric and geriatric patients and patients with nasogastric tubes, were most frequently included in oral syringe distribution systems. Twenty-six of the 73 hospitals utilizing oral syringes used them for most unit dose liquids in all drug distribution systems. The remainder reported use for specific medications or circumstances. Expiration dating policies varied from 24 hours to one year to the manufacturer's expiration dating. The survey indicates widespread use of oral syringes and identifies a need for evaluation of medication stability in these devices.

  9. [Oral fluid bacteriocidal activity in complex diagnostics of oral disbiosis].

    Science.gov (United States)

    Rabinovich, O F; Abramova, E S

    2012-01-01

    The possibility of examination of oral fluid bacteriocidal activity in complex diagnostics of oral mucosa disbiosis was evaluated. Thirty-seven patients were included in complex clinical and laboratory studies. The patients were divided in two groups: main group (30 patients exhibiting various grades of oral mucosa disbiosis) and control group (7 patients with no signs of oral disbiosis). The oral fluid bacteriocidal activity was examined by means of laser flow cytometry. Study results proved oral fluid bacteriocidal activity increase to correlate with the grade of oral mucosa disbiosis thus confirming the usefulness of the method in complex diagnostics of oral disbiosis.

  10. American Academy of Oral Medicine

    Science.gov (United States)

    ... Statements Newsletters AAOM: Representing the Discipline of Oral Medicine Oral Medicine is the discipline of dentistry concerned with the ... offers credentialing, resources and professional community for oral medicine practitioners. Our membership provides care to thousands. We ...

  11. Effects of a novel organophosphorus pesticide (RPR-V) on extra hepatic detoxifying enzymes after repeated oral doses in rats.

    Science.gov (United States)

    Mahboob, Mohammed; Kaleem, Mohammed; Siddiqui, Javed

    2004-10-01

    The effects of a novel organophosphorous pesticide, 2-butenoic acid-3-(diethoxy phosphinothionyl) ethyl ester (RPR-V) on glutathione S-transferases (GST), UDP-glucuronyl transferases (UDPGT) and the level of glutathione (GSH) were evaluated in rats after repeated oral administration at 33 microg kg(-1)day(-1) (low), 66 microg kg(-1)day(-1) (mid) and 99 microg kg(-1)day(-1) (high) for 90 days and at 28 days (withdrawal) post-treatment. GSH level and GST in kidney; GSH level in brain decreased significantly at mid and high doses on 45th and 90th day (P RPR-V has the potential to modulate the extrahepatic detoxifying enzymes and thereby interact with other physiological processes in the exposed organisms.

  12. Literatura Oral Hispanica (Hispanic Oral Literature).

    Science.gov (United States)

    McAlpine, Dave

    As part of a class in Hispanic Oral Literature, students collected pieces of folklore from various Hispanic residents in the region known as "Siouxland" in Iowa. Consisting of some of the folklore recorded from the residents, this paper includes 18 "cuentos y leyendas" (tales and legends), 48 "refranes" (proverbs), 17…

  13. Examining the association between oral health and oral HPV infection.

    Science.gov (United States)

    Bui, Thanh Cong; Markham, Christine M; Ross, Michael Wallis; Mullen, Patricia Dolan

    2013-09-01

    Oral human papillomavirus (HPV) infection is the cause of 40% to 80% of oropharyngeal cancers; yet, no published study has examined the role of oral health in oral HPV infection, either independently or in conjunction with other risk factors. This study examined the relation between oral health and oral HPV infection and the interactive effects of oral health, smoking, and oral sex on oral HPV infection. Our analyses comprised 3,439 participants ages 30 to 69 years for whom data on oral HPV and oral health were available from the nationally representative 2009-2010 National Health and Nutrition Examination Survey. Results showed that higher unadjusted prevalence of oral HPV infection was associated with four measures of oral health, including self-rated oral health as poor-to-fair [prevalence ratio (PR) = 1.56; 95% confidence interval (CI), 1.25-1.95], indicated the possibility of gum disease (PR = 1.51; 95% CI, 1.13-2.01), reported use of mouthwash to treat dental problems in the past week (PR = 1.28; 95% CI, 1.07-1.52), and higher number of teeth lost (Ptrend = 0.035). In multivariable logistic regression models, oral HPV infection had a statistically significant association with self-rated overall oral health (OR = 1.55; 95% CI, 1.15-2.09), independent of smoking and oral sex. In conclusion, poor oral health was an independent risk factor of oral HPV infection, irrespective of smoking and oral sex practices. Public health interventions may aim to promote oral hygiene and oral health as an additional measure to prevent HPV-related oral cancers.

  14. Oral health and nutrition.

    Science.gov (United States)

    Pla, G W

    1994-03-01

    The relationships between oral health conditions, dietary practices and nutritional status, and general health status in the older American are complex, with many interrelating factors. Just as inadequate nutrition can affect oral health, poor oral health status affects food choices and, thus, nutritional status. It is clearly essential that the primary care practitioner and/or screening health professionals always include an evaluation of oral status in assessment of an elderly person. Effective care for the elderly dental patient requires knowledge about the disease of aging and the impact of those diseases on oral health and nutrition, pharmacology and drug interactions and their impact on oral health status, the biology of aging including sensory changes, the relationship of general medicine and systemic diseases, and psychology and sociology. The attitudes of empathy and understanding, caring and compassion, respect and a positive attitude toward the older patient, and flexibility in treatment planning are also critical elements. The interdisciplinary team of physicians, nurses, nutrition professionals, dentists, and social service professionals must all work together to ensure that good oral health status and adequate nutrition are maintained in older Americans. Recognizing and treating oral health and nutrition problems are important in improving the health and quality of life for the elderly population. Research that can provide more answers to health care problems in this growing group; educating professionals with respect to the relationships between oral health and nutrition; and public policy changes with regard to provision and funding of nutrition services, especially when provided by registered and/or licensed nutrition professionals, contribute to improving the health and quality of life for elders.

  15. Heterologous expression and functional characterization of avian mu-class glutathione S-transferases.

    Science.gov (United States)

    Bunderson, Brett R; Kim, Ji Eun; Croasdell, Amanda; Mendoza, Kristelle M; Reed, Kent M; Coulombe, Roger A

    2013-08-01

    Hepatic glutathione S-transferases (GSTs: EC2.5.1.1.8) catalyze the detoxification of reactive electrophilic compounds, many of which are toxic and carcinogenic intermediates, via conjugation with the endogenous tripeptide glutathione (GSH). Glutathione S-transferase (GST)-mediated detoxification is a critical determinant of species susceptibility to the toxic and carcinogenic mycotoxin aflatoxin B1 (AFB1), which in resistant animals efficiently detoxifies the toxic intermediate produced by hepatic cytochrome P450 bioactivation, the exo-AFB1-8,9-epoxide (AFBO). Domestic turkeys (Meleagris gallopavo) are one of the most sensitive animals known to AFB1, a condition associated with a deficiency of hepatic GST-mediated detoxification of AFBO. We have recently shown that unlike their domestic counterparts, wild turkeys (Meleagris gallopavo silvestris), which are relatively resistant, express hepatic GST-mediated detoxification activity toward AFBO. Because of the importance of GSTs in species susceptibility, and to explore possible GST classes involved in AFB1 detoxification, we amplified, cloned, expressed and functionally characterized the hepatic mu-class GSTs tGSTM3 (GenBank accession no. JF340152), tGSTM4 (JF340153) from domestic turkeys, and a GSTM4 variant (ewGSTM4, JF340154) from Eastern wild turkeys. Predicted molecular masses of tGSTM3 and two tGSTM4 variants were 25.6 and 25.8kDa, respectively. Multiple sequence comparisons revealed four GSTM motifs and the mu-loop in both proteins. tGSTM4 has 89% amino acid sequence identity to chicken GSTM2, while tGSTM3 has 73% sequence identity to human GSTM3 (hGSTM3). Specific activities of Escherichia coli-expressed tGSTM3 toward 1-chloro-2,4-dinitrobenzene (CDNB) and peroxidase activity toward cumene hydroperoxide were five-fold greater than tGSTM4 while tGSTM4 possessed more than three-fold greater activity toward 1,2-dichloro-4-nitrobenzene (DCNB). The two enzymes displayed equal activity toward ethacrynic acid (ECA

  16. Glutathione mediated regulation of oligomeric structure and functional activity of Plasmodium falciparum glutathione S-transferase

    Directory of Open Access Journals (Sweden)

    Becker Katja

    2007-10-01

    Full Text Available Abstract Background In contrast to many other organisms, the malarial parasite Plasmodium falciparum possesses only one typical glutathione S-transferase. This enzyme, PfGST, cannot be assigned to any of the known GST classes and represents a most interesting target for antimalarial drug development. The PfGST under native conditions forms non-covalently linked higher aggregates with major population (~98% being tetramer. However, in the presence of 2 mM GSH, a dimer of PfGST is observed. Recently reported study on binding and catalytic properties of PfGST indicated a GSH dependent low-high affinity transition with simultaneous binding of two GSH molecules to PfGST dimer suggesting that GSH binds to low affinity inactive enzyme dimer converting it to high affinity functionally active dimer. In order to understand the role of GSH in tetramer-dimer transition of PfGST as well as in modulation of functional activity of the enzyme, detailed structural, functional and stability studies on recombinant PfGST in the presence and absence of GSH were carried out. Results Our data indicate that the dimer – and not the tetramer – is the active form of PfGST, and that substrate saturation is directly paralleled by dissociation of the tetramer. Furthermore, this dissociation is a reversible process indicating that the tetramer-dimer equilibrium of PfGST is defined by the surrounding GSH concentration. Equilibrium denaturation studies show that the PfGST tetramer has significantly higher stability compared to the dimer. The enhanced stability of the tetramer is likely to be due to stronger ionic interactions existing in it. Conclusion This is the first report for any GST where an alteration in oligomeric structure and not just small conformational change is observed upon GSH binding to the enzyme. Furthermore we also demonstrate a reversible mechanism of regulation of functional activity of Plasmodium falciparum glutathione S-transferase via GSH induced

  17. Thiamine diphosphate adenylyl transferase from E. coli: functional characterization of the enzyme synthesizing adenosine thiamine triphosphate

    Directory of Open Access Journals (Sweden)

    Brans Alain

    2007-08-01

    Full Text Available Abstract Background We have recently identified a new thiamine derivative, adenosine thiamine triphosphate (AThTP, in E. coli. In intact bacteria, this nucleotide is synthesized only in the absence of a metabolizable carbon source and quickly disappears as soon as the cells receive a carbon source such as glucose. Thus, we hypothesized that AThTP may be a signal produced in response to carbon starvation. Results Here we show that, in bacterial extracts, the biosynthesis of AThTP is carried out from thiamine diphosphate (ThDP and ADP or ATP by a soluble high molecular mass nucleotidyl transferase. We partially purified this enzyme and characterized some of its functional properties. The enzyme activity had an absolute requirement for divalent metal ions, such as Mn2+ or Mg2+, as well as for a heat-stable soluble activator present in bacterial extracts. The enzyme has a pH optimum of 6.5–7.0 and a high Km for ThDP (5 mM, suggesting that, in vivo, the rate of AThTP synthesis is proportional to the free ThDP concentration. When ADP was used as the variable substrate at a fixed ThDP concentration, a sigmoid curve was obtained, with a Hill coefficient of 2.1 and an S0.5 value of 0.08 mM. The specificity of the AThTP synthesizing enzyme with respect to nucleotide substrate is restricted to ATP/ADP, and only ThDP can serve as the second substrate of the reaction. We tentatively named this enzyme ThDP adenylyl transferase (EC 2.7.7.65. Conclusion This is the first demonstration of an enzyme activity transferring a nucleotidyl group on thiamine diphosphate to produce AThTP. The existence of a mechanism for the enzymatic synthesis of this compound is in agreement with the hypothesis of a non-cofactor role for thiamine derivatives in living cells.

  18. Orotate phosphoribosyl transferase mRNA expression and the response of cholangiocarcinoma to 5-fluorouracil

    Institute of Scientific and Technical Information of China (English)

    Chariya Hahnvajanawong; Jariya Chaiyagool; Wunchana Seubwai; Vajarabhongsa Bhudhisawasdi; Nisana Namwat; Narong Khuntikeo; Banchob Sripa

    2012-01-01

    AIM:To determine whether expression of certain enzymes related to 5-fluorouracil (5-FU) metabolism predicts 5-FU chemosensitivity in cholangiocarcinoma (CCA).METHODS:The histoculture drug response assay (HDRA) was performed using surgically resected CCA tissues.Tumor cell viability was determined morphologically with hematoxylin and eosin-and terminal deoxynucleotide transferase-mediated dUTP nick-end labeling-stained tissues.The mRNA expression of thymidine phosphorylase (TP),orotate phosphoribosyl transferase (OPRT),thymidylate synthase (TS),and dihydropyrimidine dehydrogenase (DPD) was determined with realtime reverse transcriptase-polymerase chain reaction.The levels of gene expression and the sensitivity to 5-FU were evaluated.RESULTS:Twenty-three CCA tissues were obtained from patients who had been diagnosed with intrahepatic CCA and who underwent surgical resection at Srinagarind Hospital,Khon Kaen University from 2007 to 2009.HDRA was used to determine the response of these CCA tissues to 5-FU.Based on the dose-response curve,200 μg/mL 5-FU was selected as the test concentration.The percentage of inhibition index at the median point was selected as the cut-off point to differentiate the responding and non-responding tumors to 5-FU.When the relationship between TP,OPRT,TS and DPD mRNA expression levels and the sensitivity of CCA tissues to 5-FU was examined,only OPRT mRNA expression was significantly correlated with the response to 5-FU.The mean expression level of OPRT was significantly higher in the responder group compared to the non-responder group (0.41 ± 0.25 vs 0.22 ± 0.12,P < 0.05).CONCLUSION:OPRT mRNA expression may be a useful predictor of 5-FU chemosensitivity of CCA.Whether OPRT mRNA could be used to predict the success of 5-FU chemotherapy in CCA patients requires confirmation in patients.

  19. Structural snapshots along the reaction pathway of Yersinia pestis RipA, a putative butyryl-CoA transferase

    Energy Technology Data Exchange (ETDEWEB)

    Torres, Rodrigo; Lan, Benson; Latif, Yama; Chim, Nicholas [UC Irvine, 2212 Natural Sciences I, Irvine, CA 92697 (United States); Goulding, Celia W., E-mail: celia.goulding@uci.edu [UC Irvine, 2212 Natural Sciences I, Irvine, CA 92697 (United States); UC Irvine, 2302 Natural Sciences I, Irvine, CA 92697 (United States)

    2014-04-01

    The crystal structures of Y. pestis RipA mutants were determined to provide insights into the CoA transferase reaction pathway. Yersinia pestis, the causative agent of bubonic plague, is able to survive in both extracellular and intracellular environments within the human host, although its intracellular survival within macrophages is poorly understood. A novel Y. pestis three-gene rip (required for intracellular proliferation) operon, and in particular ripA, has been shown to be essential for survival and replication in interferon γ-induced macrophages. RipA was previously characterized as a putative butyryl-CoA transferase proposed to yield butyrate, a known anti-inflammatory shown to lower macrophage-produced NO levels. RipA belongs to the family I CoA transferases, which share structural homology, a conserved catalytic glutamate which forms a covalent CoA-thioester intermediate and a flexible loop adjacent to the active site known as the G(V/I)G loop. Here, functional and structural analyses of several RipA mutants are presented in an effort to dissect the CoA transferase mechanism of RipA. In particular, E61V, M31G and F60M RipA mutants show increased butyryl-CoA transferase activities when compared with wild-type RipA. Furthermore, the X-ray crystal structures of E61V, M31G and F60M RipA mutants, when compared with the wild-type RipA structure, reveal important conformational changes orchestrated by a conserved acyl-group binding-pocket phenylalanine, Phe85, and the G(V/I)G loop. Binary structures of M31G RipA and F60M RipA with two distinct CoA substrate conformations are also presented. Taken together, these data provide CoA transferase reaction snapshots of an open apo RipA, a closed glutamyl-anhydride intermediate and an open CoA-thioester intermediate. Furthermore, biochemical analyses support essential roles for both the catalytic glutamate and the flexible G(V/I)G loop along the reaction pathway, although further research is required to fully

  20. Etiology of oral habits.

    Science.gov (United States)

    Bayardo, R E; Mejia, J J; Orozco, S; Montoya, K

    1996-01-01

    The pedodontic admission histories of 1600 Mexican children were analyzed, to determine general epidemiologic factors or oral habits, as well as their relationship with identifiable biopsychosociologic factors. Fifty-six percent of the children gave evidence of an oral habit, with significant predisposition among female patients, single children, subjects in poor physical health (particularly from allergies), as well as children with histories of chronic health problems. Oral habits should be considered a major health hazard because of their high incidence. Successful treatment requires a multidisciplinary approach to the basic cause of the problem.

  1. Microbioma oral humano

    OpenAIRE

    Silva, Joana Pinto Oliveira e

    2016-01-01

    O microbioma oral humano é constituído por um vasto conjunto de microrganismos presentes na cavidade oral. Analisando a cavidade oral podemos verificar que nela existem mais de 700 espécies de bactérias responsáveis pelo domínio de parte do microbioma humano, tornando-a um importante local de estudo. É um dos habitats com maior diversidade no corpo humano onde esses microrganismos se apresentam de forma organizada e estruturada. Estes habitats estão intimamente relacionados ...

  2. Amiloidosis oral nodular Oral nodular amyloidosis

    Directory of Open Access Journals (Sweden)

    P. Martos Díaz

    2008-02-01

    Full Text Available Introducción. La amiloidosis constituye una entidad marcada por el depósito de amiloide en diferentes tejidos. En la cavidad oral se manifiesta habitualmente en forma de macroglosia, y más raramente, como nódulos dispuestos en la superficie. Caso clínico. Varón afecto de Mieloma Múltiple, que comienza con lesiones nodulares en labio inferior y lengua. A raíz de estas lesiones, mediante estudio histológico, es diagnosticado de Amiloidosis Sistémica. Discusión. Los nódulos amiloideos en la cavidad oral, constituyen una manifestación rara de la amiloidosis sistémica. Su aparición conlleva la necesidad de realizar un diagnostico diferencial con otras entidades y el diagnostico de certeza se obtiene mediante el análisis histológico.Introduction. Amyloidosis is a condition characterized by the deposit of amyloid in different tissues. In the oral cavity it is usually manifested as macroglossia and, more rarely, as nodules on the surface. Clinical case. A man had multiple myeloma that began with nodular lesions of the lower lip and tongue. As a result of these lesions, the patient was diagnosed of systemic amyloidosis by histological study. Discussion. Amyloid nodules in the oral cavity are a rare manifestation of systemic amyloidosis. Its appearance entails the necessity to make I diagnose differential with other organizations and I diagnose of certainty is obtained by means of the histological analysis.

  3. Oral sex and oral health: An enigma in itself

    Directory of Open Access Journals (Sweden)

    Tarun Kumar

    2015-01-01

    Full Text Available Oral sex is commonly practiced by sexually active couples of various age groups, including male-female and same-gender adolescents. The various type of oral sex practices are fellatio, cunnilingus, and analingus. Oral sex can transmit oral, respiratory, and genital infections from one site in body to the other. Oral health has a direct correlation on the transmission of infection; a cut in the mouth, bleeding gums, lip sores or broken skin increases chances of life-threatening infections. Although oral sex is considered a low risk activity, it is important to use protection such as physical barriers, health and medical issues, ethical issues, and oral hygiene and dental issues. The ulcerations or unhealthy periodontium in mouth accelerates the phenomenon of transmission of infections into the circulation. Thus, consequences of unhealthy or painful oral cavity are significant and oral health should be given paramount importance for the practice of oral sex.

  4. Oral Cancer Exam

    Medline Plus

    Full Text Available ... Z Index Search Text size: Website Contents NIDCR Home Oral Health Diseases and Conditions Gum Disease TMJ ... site’s privacy policy when you follow the link. Home Contact Us Viewers and Players Site Map FOIA ...

  5. Oral Cancer Exam

    Medline Plus

    Full Text Available ... Cancer Dry Mouth Burning Mouth Tooth Decay See All Oral Complications of Systemic Diseases Cancer Treatment Developmental Disabilities Diabetes Heart Disease HIV/AIDS See All Order Publications English and Spanish brochures available free ...

  6. Oral Cancer Exam

    Medline Plus

    Full Text Available ... it can be treated more successfully. Publications​ For Health Professionals Detecting Oral Cancer: A Guide for Health Care Professionals A step-by-step, illustrated guide ...

  7. Oral Cancer Exam

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    Full Text Available ... Submission of Applications Grants 101 (How to Write a Grant) Questions and Answers Grant Writing Tips Careers & ... successfully. Publications​ For Health Professionals Detecting Oral Cancer: A Guide for Health Care Professionals A step-by- ...

  8. Oral Cancer Exam

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    Full Text Available ... Research Programs (Extramural Research) NIDCR Laboratories (Intramural Research) Science News in Brief Study Takes First Comprehensive Look ... Programs Careers in Dental Research See All Continuing Education Practical Oral Care for People With Developmental Disabilities – ...

  9. Oral Hypersensitivity Reactions

    Science.gov (United States)

    ... food, food additives, drugs, oral hygiene products, and dental materials. Q: Are there any specific foods that are ... dental treatment trigger a hypersensitivity reaction? A: Some dental materials used by the dentist can cause a hypersensitivity ...

  10. Oral Cancer Exam

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    Full Text Available ... In Skip to Main Content National Institute of Dental and Craniofacial Research (NIDCR) Improving the Nation's Oral ... High School and College Students Recent College Graduates Dental and Medical Students See All Careers & Training Opportunities ...

  11. Oral Cancer Exam

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    Full Text Available ... it can be treated more successfully. Publications​ For Health Professionals Detecting Oral Cancer: A Guide for Health Care Professionals A step-by-step, illustrated guide ...

  12. Leucoplasia oral: Conceptos actuales

    Directory of Open Access Journals (Sweden)

    M. Escribano-Bermejo

    Full Text Available La leucoplasia es la lesión premaligna más frecuente de la cavidad oral. La Organización Mundial de la Salud la define clínicamente como una lesión predominantemente blanca de la mucosa oral que no puede caracterizarse como ninguna otra lesión conocida y con una elevada tendencia a convertirse en un cáncer oral. El objetivo de esta revisión es hacer un repaso al conocimiento actual acerca de la leucoplasia oral prestando especial atención a su nomenclatura, su etiología, su potencial maligno y su tratamiento.

  13. Oral Cancer Exam

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    Full Text Available ... Main Content National Institute of Dental and Craniofacial Research (NIDCR) Improving the Nation's Oral Health National Institutes ... Browse Studies by Topic NIDCR-Sponsored Clinical Trials Research NIDCR Strategic Plan Research Results Tools for Researchers ...

  14. Oral Cancer Exam

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    Full Text Available ... and Medical Students See All Careers & Training Opportunities Job Openings Loan Repayment Programs Careers in Dental Research See All Continuing Education Practical Oral Care for People With Developmental Disabilities – ...

  15. Oral Cancer Exam

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    Full Text Available ... Diabetes Heart Disease HIV/AIDS See All Order Publications English and Spanish brochures available free of charge. ... early—when it can be treated more successfully. Publications​ For Health Professionals Detecting Oral Cancer: A Guide ...

  16. Oral Cancer Exam

    Medline Plus

    Full Text Available ... Submission of Applications Grants 101 (How to Write a Grant) Questions and Answers Grant Writing Tips Careers & ... successfully. Publications​ For Health Professionals Detecting Oral Cancer: A Guide for Health Care Professionals A step-by- ...

  17. Fostering oral presentation performance

    NARCIS (Netherlands)

    Ginkel, van Stan; Gulikers, Judith; Biemans, Harm; Mulder, Martin

    2016-01-01

    Previous research revealed significant differences in the effectiveness of various feedback sources for encouraging students’ oral presentation performance. While former studies emphasised the superiority of teacher feedback, it remains unclear whether the quality of feedback actually differs bet

  18. Oral Cancer Facts

    Science.gov (United States)

    ... shown to participate in their development. These include lichen planus, an inflammatory disease of the oral soft ... at an uncontrolled rate, is unable to repair DNA damage within itself, or refuses to self destruct ...

  19. Oral Cancer Exam

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    Full Text Available ... Answers Grant Writing Tips Careers & Training Fellowships and Internships for... High School and College Students Recent College ... signs and symptoms of oral cancer, and the importance of detecting the disease in its early stages. ...

  20. Oral Cancer Exam

    Science.gov (United States)

    ... Answers Grant Writing Tips Careers & Training Fellowships and Internships for... High School and College Students Recent College ... signs and symptoms of oral cancer, and the importance of detecting the disease in its early stages. ...

  1. Characterization of Discrete Phosphopantetheinyl Transferases in Streptomyces tsukubaensis L19 Unveils a Complicate Phosphopantetheinylation Network

    Science.gov (United States)

    Wang, Yue-Yue; Zhang, Xiao-Sheng; Luo, Hong-Dou; Ren, Ni-Ni; Jiang, Xin-Hang; Jiang, Hui; Li, Yong-Quan

    2016-01-01

    Phosphopantetheinyl transferases (PPTases) play essential roles in both primary metabolisms and secondary metabolisms via post-translational modification of acyl carrier proteins (ACPs) and peptidyl carrier proteins (PCPs). In this study, an industrial FK506 producing strain Streptomyces tsukubaensis L19, together with Streptomyces avermitilis, was identified to contain the highest number (five) of discrete PPTases known among any species thus far examined. Characterization of the five PPTases in S. tsukubaensis L19 unveiled that stw ACP, an ACP in a type II PKS, was phosphopantetheinylated by three PPTases FKPPT1, FKPPT3, and FKACPS; sts FAS ACP, the ACP in fatty acid synthase (FAS), was phosphopantetheinylated by three PPTases FKPPT2, FKPPT3, and FKACPS; TcsA-ACP, an ACP involved in FK506 biosynthesis, was phosphopantetheinylated by two PPTases FKPPT3 and FKACPS; FkbP-PCP, an PCP involved in FK506 biosynthesis, was phosphopantetheinylated by all of these five PPTases FKPPT1-4 and FKACPS. Our results here indicate that the functions of these PPTases complement each other for ACPs/PCPs substrates, suggesting a complicate phosphopantetheinylation network in S. tsukubaensis L19. Engineering of these PPTases in S. tsukubaensis L19 resulted in a mutant strain that can improve FK506 production. PMID:27052100

  2. Recognition and Detoxification of the Insecticide DDT by Drosophila melanogaster Glutathione S-Transferase D1

    Energy Technology Data Exchange (ETDEWEB)

    Low, Wai Yee; Feil, Susanne C.; Ng, Hooi Ling; Gorman, Michael A.; Morton, Craig J.; Pyke, James; McConville, Malcolm J.; Bieri, Michael; Mok, Yee-Foong; Robin, Charles; Gooley, Paul R.; Parker, Michael W.; Batterham, Philip (SVIMR-A); (Melbourne)

    2010-06-14

    GSTD1 is one of several insect glutathione S-transferases capable of metabolizing the insecticide DDT. Here we use crystallography and NMR to elucidate the binding of DDT and glutathione to GSTD1. The crystal structure of Drosophila melanogaster GSTD1 has been determined to 1.1 {angstrom} resolution, which reveals that the enzyme adopts the canonical GST fold but with a partially occluded active site caused by the packing of a C-terminal helix against one wall of the binding site for substrates. This helix would need to unwind or be displaced to enable catalysis. When the C-terminal helix is removed from the model of the crystal structure, DDT can be computationally docked into the active site in an orientation favoring catalysis. Two-dimensional {sup 1}H,{sup 15}N heteronuclear single-quantum coherence NMR experiments of GSTD1 indicate that conformational changes occur upon glutathione and DDT binding and the residues that broaden upon DDT binding support the predicted binding site. We also show that the ancestral GSTD1 is likely to have possessed DDT dehydrochlorinase activity because both GSTD1 from D. melanogaster and its sibling species, Drosophila simulans, have this activity.

  3. PLLA-PCys co-electrospun fibers for capture and elution of glutathione S-transferase

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    The copolymer poly(L-lactic acid)-b-poly(L-cysteine) (PLA-b-PCys) was co-electrospun with PLGA into ultrafine fibers. The reduced glutathione (GSH) was conjugated to the fiber surfaces via disulfide bonds. The glutathione S-transferase (GST) was captured onto the GSH fibers via specific substrate-enzyme interaction between the bound GSH and GST. The captured GST was eluted with free GSH aqueous solution and lyophilized to get pure GST powders. The results show that the GSH moieties on the fiber surface retain the bioactivity of the free GSH and thus they can bind specifically with GST and the GST in solution is captured onto the fiber surface. In addition, the bound GSH is not as active as free GSH so that the captured GST can be eluted off from the fiber by free GSH aqueous solution. Based on this principle, GST itself or its fused proteins can be separated and purified very easily. The preliminary purification efficiency is 6.5 mg·(gPCys)-1. Further improvements are undertaken.

  4. Induction of Epoxide Hydrolase, Glucuronosyl Transferase, and Sulfotransferase by Phenethyl Isothiocyanate in Male Wistar Albino Rats

    Directory of Open Access Journals (Sweden)

    Ahmad Faizal Abdull Razis

    2014-01-01

    Full Text Available Phenethyl isothiocyanate (PEITC is an isothiocyanate found in watercress as the glucosinolate (gluconasturtiin. The isothiocyanate is converted from the glucosinolate by intestinal microflora or when contacted with myrosinase during the chopping and mastication of the vegetable. PEITC manifested protection against chemically-induced cancers in various tissues. A potential mechanism of chemoprevention is by modulating the metabolism of carcinogens so as to promote deactivation. The principal objective of this study was to investigate in rats the effect of PEITC on carcinogen-metabolising enzyme systems such as sulfotransferase (SULT, N-acetyltransferase (NAT, glucuronosyl transferase (UDP, and epoxide hydrolase (EH following exposure to low doses that simulate human dietary intake. Rats were fed for 2 weeks diets supplemented with PEITC at 0.06 µmol/g (low dose, i.e., dietary intake, 0.6 µmol/g (medium dose, and 6.0 µmol/g (high dose, and the enzymes were monitored in rat liver. At the Low dose, no induction of the SULT, NAT, and EH was noted, whereas UDP level was elevated. At the Medium dose, only SULT level was increased, whereas at the High dose marked increase in EH level was observed. It is concluded that PEITC modulates carcinogen-metabolising enzyme systems at doses reflecting human intake thus elucidating the mechanism of its chemoprevention.

  5. Serum γ-Glutamyl Transferase Is Inversely Associated with Bone Mineral Density Independently of Alcohol Consumption

    Directory of Open Access Journals (Sweden)

    Han Seok Choi

    2016-03-01

    Full Text Available Backgroundγ-Glutamyl transferase (GGT is a well-known marker of chronic alcohol consumption or hepatobiliary diseases. A number of studies have demonstrated that serum levels of GGT are independently associated with cardiovascular and metabolic disorders. The purpose of this study was to test if serum GGT levels are associated with bone mineral density (BMD in Korean adults.MethodsA total of 462 subjects (289 men and 173 women, who visited Severance Hospital for medical checkup, were included in this study. BMD was measured using dual energy X-ray absorptiometry. Cross-sectional association between serum GGT and BMD was evaluated.ResultsAs serum GGT levels increased from the lowest tertile (tertile 1 to the highest tertile (tertile 3, BMD decreased after adjusting for confounders such as age, body mass index, amount of alcohol consumed, smoking, regular exercise, postmenopausal state (in women, hypertension, diabetes mellitus, and hypercholesterolemia. A multiple linear regression analysis showed a negative association between log-transformed serum GGT levels and BMD. In a multiple logistic regression analysis, tertile 3 of serum GGT level was associated with an increased risk for low bone mass compared to tertile 1 (odds ratio, 2.271; 95% confidence interval, 1.340 to 3.850; P=0.002.ConclusionSerum GGT level was inversely associated with BMD in Korean adults. Further study is necessary to fully elucidate the mechanism of the inverse relationship.

  6. A glutathione S-transferase gene associated with antioxidant properties isolated from Apis cerana cerana

    Science.gov (United States)

    Liu, Shuchang; Liu, Feng; Jia, Haihong; Yan, Yan; Wang, Hongfang; Guo, Xingqi; Xu, Baohua

    2016-06-01

    Glutathione S-transferases (GSTs) are an important family of multifunctional enzymes in aerobic organisms. They play a crucial role in the detoxification of exogenous compounds, especially insecticides, and protection against oxidative stress. Most previous studies of GSTs in insects have largely focused on their role in insecticide resistance. Here, we isolated a theta class GST gene designated AccGSTT1 from Apis cerana cerana and aimed to explore its antioxidant and antibacterial attributes. Analyses of homology and phylogenetic relationships suggested that the predicted amino acid sequence of AccGSTT1 shares a high level of identity with the other hymenopteran GSTs and that it was conserved during evolution. Quantitative real-time PCR showed that AccGSTT1 is most highly expressed in adult stages and that the expression profile of this gene is significantly altered in response to various abiotic stresses. These results were confirmed using western blot analysis. Additionally, a disc diffusion assay showed that a recombinant AccGSTT1 protein may be roughly capable of inhibiting bacterial growth and that it reduces the resistance of Escherichia coli cells to multiple adverse stresses. Taken together, these data indicate that AccGSTT1 may play an important role in antioxidant processes under adverse stress conditions.

  7. Insights into ligand binding to a glutathione S-transferase from mango: Structure, thermodynamics and kinetics.

    Science.gov (United States)

    Valenzuela-Chavira, Ignacio; Contreras-Vergara, Carmen A; Arvizu-Flores, Aldo A; Serrano-Posada, Hugo; Lopez-Zavala, Alonso A; García-Orozco, Karina D; Hernandez-Paredes, Javier; Rudiño-Piñera, Enrique; Stojanoff, Vivian; Sotelo-Mundo, Rogerio R; Islas-Osuna, Maria A

    2017-04-01

    We studied a mango glutathione S-transferase (GST) (Mangifera indica) bound to glutathione (GSH) and S-hexyl glutathione (GSX). This GST Tau class (MiGSTU) had a molecular mass of 25.5 kDa. MiGSTU Michaelis-Menten kinetic constants were determined for their substrates obtaining a Km, Vmax and kcat for CDNB of 0.792 mM, 80.58 mM min(-1) and 68.49 s(-1) respectively and 0.693 mM, 105.32 mM min(-1) and 89.57 s(-1), for reduced GSH respectively. MiGSTU had a micromolar affinity towards GSH (5.2 μM) or GSX (7.8 μM). The crystal structure of the MiGSTU in apo or bound to GSH or GSX generated a model that explains the thermodynamic signatures of binding and showed the importance of enthalpic-entropic compensation in ligand binding to Tau-class GST enzymes. Copyright © 2017 Elsevier B.V. and Société Française de Biochimie et Biologie Moléculaire (SFBBM). All rights reserved.

  8. Elevation of gamma-glutamyl transferase in adult: Should we think about progressive familiar intrahepatic cholestasis?

    Science.gov (United States)

    Oliveira, Hugo M; Pereira, Cláudia; Santos Silva, Ermelinda; Pinto-Basto, Jorge; Pessegueiro Miranda, Helena

    2016-02-01

    There are three types of progressive familial intrahepatic cholestasis (PFIC). Type 3 is characterized by elevated gamma-glutamyl transferase (γ-GT) and it can be diagnosed in adolescence/adulthood. The genetic defect of PFIC 3 appears to explain the pathogenesis of intrahepatic cholestasis of pregnancy (ICP). Draw attention to this rare disease, especially in adulthood, and clarify the association between ICP and PFIC 3. We describe a series of cases from a Portuguese northern family with two brothers presenting chronic cholestasis since adolescence. Brother 1: since 15-years-old with pruritus and elevated γ-GT ∼6x. Brother 2: pre-term, due to severe maternal pruritus and jaundice, since 13-years-old with pruritus, jaundice and ∼8x γ-GT elevation. Common causes of cholestasis were excluded and liver histologies were nonspecific. Research for mutation on ABCB4 gene showed mutations in both alleles. Disease and mechanisms that determine cholestasis are complex and their understanding may provide new therapeutics. Copyright © 2015 Editrice Gastroenterologica Italiana S.r.l. Published by Elsevier Ltd. All rights reserved.

  9. Metabolic engineering of Clostridium tyrobutyricum for n-butanol production: effects of CoA transferase.

    Science.gov (United States)

    Yu, Le; Zhao, Jingbo; Xu, Mengmeng; Dong, Jie; Varghese, Saju; Yu, Mingrui; Tang, I-Ching; Yang, Shang-Tian

    2015-06-01

    The overexpression of CoA transferase (ctfAB), which catalyzes the reaction: acetate/butyrate + acetoacetyl-CoA → acetyl/butyryl-CoA + acetoacetate, was studied for its effects on acid reassimilation and butanol biosynthesis in Clostridium tyrobutyricum (Δack, adhE2). The plasmid pMTL007 was used to co-express adhE2 and ctfAB from Clostridium acetobutylicum ATCC 824. In addition, the sol operon containing ctfAB, adc (acetoacetate decarboxylase), and ald (aldehyde dehydrogenase) was also cloned from Clostridium beijerinckii NCIMB 8052 and expressed in C. tyrobutyricum (Δack, adhE2). Mutants expressing these genes were evaluated for their ability to produce butanol from glucose in batch fermentations at pH 5.0 and 6.0. Compared to C. tyrobutyricum (Δack, adhE2) without expressing ctfAB, all mutants with ctfAB overexpression produced more butanol, with butanol yield increased to 0.22 - 0.26 g/g (vs. 0.10 - 0.13 g/g) and productivity to 0.35 g/l h (vs. 0.13 g/l h) because of the reduced acetate and butyrate production. The expression of ctfAB also resulted in acetone production from acetoacetate through a non-enzymatic decarboxylation.

  10. Crystallization and X-ray diffraction studies of glutathione S-transferase from Escherichia coli

    Science.gov (United States)

    Nishida, Motohiko; Harada, Shigeharu; Satow, Yoshinori; Inoue, Hideshi; Takahashi, Kenji

    1996-10-01

    Crystals of glutathione S-transferase from Escherichia coli have been obtained by use of polyethylene glycol 6000 as a precipitant. The crystallization was performed in the presence of a glutathione sulfonate inhibitor under the acidic condition, with combination of the sitting-drop vapour-diffusion and the macro-seeding procedures. The crystals are of a thin-plate shape with typical sizes of 1.0 × 0.5 × 0.1 mm, and are stable against X-ray irradiation. They belong to the space group P2 12 12 1 with cell parameters of a = 90.47 Å, b = 93.87 Å and c = 51.10 Å, and diffract X-rays at least up to 2.3 Å resolution. The solvent content is 48% in volume, when a homodimeric molecule of the enzyme is assumed to occupy an asymmetric unit of the crystal. The crystals are suitable for three-dimensional structural studies. Diffraction data of the native crystal have been collected.

  11. Immunohistochemical localization of glutathione S-transferase-pi in human colorectal polyps

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    AIM: To investigate the distribution of the placental form of glutathione-S-transferase (GST) in colon polyps in order to evaluate the role of GST-pi in these tissues. METHODS: Sixteen polyp tissues removed at colon- oscopy were examined. Tissues were investigated his- tologicaUy and ultrastructurally. GST-pi expression was also analysed immunohistochemically, using peroxidase anti-peroxidase (PAP) method and immunogold label- ling method, for light and electron microscope respec- tively. RESULTS: All polyp tissues examined were adenoma of low, mild and high- grade dysplasia as shown in the histopathological reports. Nevertheless, the examina- tion of the above specimens with electron microscope revealed that 3 of 9 adenoma of mild dysplasia had ultrastuctural features similar to high-grade dysplasia adenoma. GST-pi was variably expressed in adenoma, with the lowest relative levels occurring in low-grade adenoma and the highest levels found in high-grade adenoma. GST-pi was located mainly in undifferentiat- ed epithelial cells. GST-pi positive particles were found in the cytoplasm and especially in the nucleus adjacent to the nuclear membrane of these cells. CONCLUSION: The overexpression of GST-pi in mild- grade adenomas with significant subcellular changes and in the majority of high-grade dysplasia adenoma suggests that this might be related to the carcinogenetic proceeding. Immunohistochemical localization of GST-pi in combination with ultrastructural changes indicate that GST-pi might be a sensitive agent for the detection of preneoplastic transformations in adenoma.

  12. Nicotinamide N-methyl Transferase (NNMT) Gene Polymorphisms and Risk for Spina Bifida

    Science.gov (United States)

    Lu, Wei; Zhu, Huiping; Wen, Shu; Yang, Wei; Shaw, Gary M.; Lammer, Edward J.; Finnell, Richard H.

    2008-01-01

    Background Moderate hyperhomocysteinemia is a known risk factor for neural tube defects (NTDs) in a variety of experimental model systems and is believed to be important in humans as well. The enzyme Nicotinamide N-methyl transferase (NNMT) was identified in a genome-wide linkage scan as being an important regulator of homocysteine (Hcy) homeostasis in a Spanish population making it an interesting candidate gene for NTDs. Methods We evaluated eleven SNPs of the NNMT gene in our study population. In this study, 251 cases (infants with spina bifida) and 335 controls (non-malformed infants), born during the periods 1983−1986 in selected counties in California, were genotyped for variants of the NNMT gene. Allelic, genotype and haplotype associations with spina bifida risk were evaluated and analyzed. Results None of the SNPs studied alone showed allelic or genotypic associations with spina bifida. However, the TCAG haplotype for block 3 (rs2852447, ra2852425, rs4646337 and rs11569688) showed a decreased risk for spina bifida among non-Hispanic whites (OR: 0.4; 95%CI: 0.1−1.0). Conclusion No association was found between infant NNMT gene variants and risk for spina bifida in our study population. However, small sample sizes for most variant groups and for phase-unknown haplotype data limited the power of the study. PMID:18553462

  13. Legionella shows a diverse secondary metabolism dependent on a broad spectrum Sfp-type phosphopantetheinyl transferase

    Directory of Open Access Journals (Sweden)

    Nicholas J. Tobias

    2016-11-01

    Full Text Available Several members of the genus Legionella cause Legionnaires’ disease, a potentially debilitating form of pneumonia. Studies frequently focus on the abundant number of virulence factors present in this genus. However, what is often overlooked is the role of secondary metabolites from Legionella. Following whole genome sequencing, we assembled and annotated the Legionella parisiensis DSM 19216 genome. Together with 14 other members of the Legionella, we performed comparative genomics and analysed the secondary metabolite potential of each strain. We found that Legionella contains a huge variety of biosynthetic gene clusters (BGCs that are potentially making a significant number of novel natural products with undefined function. Surprisingly, only a single Sfp-like phosphopantetheinyl transferase is found in all Legionella strains analyzed that might be responsible for the activation of all carrier proteins in primary (fatty acid biosynthesis and secondary metabolism (polyketide and non-ribosomal peptide synthesis. Using conserved active site motifs, we predict some novel compounds that are probably involved in cell-cell communication, differing to known communication systems. We identify several gene clusters, which may represent novel signaling mechanisms and demonstrate the natural product potential of Legionella.

  14. Characterization and evolutionary implications of the triad Asp-Xxx-Glu in group II phosphopantetheinyl transferases.

    Science.gov (United States)

    Wang, Yue-Yue; Li, Yu-Dong; Liu, Jian-Bo; Ran, Xin-Xin; Guo, Yuan-Yang; Ren, Ni-Ni; Chen, Xin; Jiang, Hui; Li, Yong-Quan

    2014-01-01

    Phosphopantetheinyl transferases (PPTases), which play an essential role in both primary and secondary metabolism, are magnesium binding enzymes. In this study, we characterized the magnesium binding residues of all known group II PPTases by biochemical and evolutionary analysis. Our results suggested that group II PPTases could be classified into two subgroups, two-magnesium-binding-residue-PPTases containing the triad Asp-Xxx-Glu and three-magnesium-binding-residue-PPTases containing the triad Asp-Glu-Glu. Mutations of two three-magnesium-binding-residue-PPTases and one two-magnesium-binding-residue-PPTase indicate that the first and the third residues in the triads are essential to activities; the second residues in the triads are non-essential. Although variations of the second residues in the triad Asp-Xxx-Glu exist throughout the whole phylogenetic tree, the second residues are conserved in animals, plants, algae, and most prokaryotes, respectively. Evolutionary analysis suggests that: the animal group II PPTases may originate from one common ancestor; the plant two-magnesium-binding-residue-PPTases may originate from one common ancestor; the plant three-magnesium-binding-residue-PPTases may derive from horizontal gene transfer from prokaryotes.

  15. Study on the biochemical characterization of herbicide detoxification enzyme, glutathione S-transferase.

    Science.gov (United States)

    Cho, Hyun-Young; Kong, Kwang-Hoon

    2007-01-01

    To gain further insight into herbicide detoxification, we studied the herbicide activity and specificity toward glutathione S-transferases from human and rice. In this study, the genes of the plant specific phi and tau class GST enzymes from Oryza sativa (OsGST) and human pi class GST enzyme (hGSTP1-1) were cloned and expressed in Escherichia coli with the pET and pKK vector systems, respectively. The gene products were purified to homogeneity by GSH Sepharose affinity column chromatography. The herbicide specificity of the enzymes was investigated by enzyme-catalyzed conjugation of GSH with chloroacetanilide, diphenylether and chloro-s-triazine herbicides. The hGSTP1-1 showed very high specific activity toward atrazine. On the other hand, the phi class OsGST enzymes showed high specific activity toward chloroacetanilide herbicides, acetochlor, alachlor and metolachlor. The tau class GST enzymes displayed remarkable activity toward the diphenylether herbicide, fluorodifen. From these results, we conclude that the phi and the tau class GST enzymes show herbicide specificities and also they play an important role in the detoxification reaction of plant toward herbicides.

  16. Targeted label-free approach for quantification of epoxide hydrolase and glutathione transferases in microsomes.

    Science.gov (United States)

    Song, Wei; Yu, Longjiang; Peng, Zhihong

    2015-06-01

    The aim of this study was to investigate the expression and organ distribution of cytochrome P450 (CYP450) enzymes, microsomal epoxide hydrolase (MEH), and microsomal glutathione-S-transferase (MGST 1, 2, 3) in human liver, lung, intestinal, and kidney microsomes by targeted peptide-based quantification using nano liquid chromatography-tandem multiple reaction monitoring (nano LC-MRM). Applying this method, we analyzed 16 human liver microsomes and pooled lung, kidney, and intestine microsomes. Nine of the CYP450s (CYP1A2, 2B6, 2C8, 2C9, 2C19, 2D6, 2E1, 3A4, 3A5) could be quantified in liver. Except for CYP3A4 and 3A5 existing in intestine, other CYP450s had little content (<0.1 pmol/mg protein) in extrahepatic tissues. MEH and MGSTs could be quantified both in hepatic and in extrahepatic tissues. The highest concentrations of MEH and MGST 1, 2 were found in liver; conversely MGST 3 was abundant in human kidney and intestine compared to liver. The targeted proteomics assay described here can be broadly and efficiently utilized as a tool for investigating the targeted proteins. The method also provides novel CYP450s, MEH, and MGSTs expression data in human hepatic and extrahepatic tissues that will benefit rational approaches to evaluate metabolism in drug development.

  17. Glutathione S-transferase P1 ILE105Val polymorphism in occupationally exposed bladder cancer cases.

    Science.gov (United States)

    Kopps, Silke; Angeli-Greaves, Miriam; Blaszkewicz, Meinolf; Prager, Hans-Martin; Roemer, Hermann C; Lohlein, Dietrich; Weistenhofer, Wobbeke; Bolt, Hermann M; Golka, Klaus

    2008-01-01

    The genotype glutathione S-transferase P1 (GSTP1) influences the risk for bladder cancer among Chinese workers occupationally exposed to benzidine. Studies of Caucasian bladder cancer cases without known occupational exposures showed conflicting results. Research was thus conducted to define the role of GSTP1 genotypes in Caucasian bladder cancer cases with an occupational history of exposure to aromatic amines. DNA from 143 cases reported to the Industrial Professional Associations (Berufsgenossenschaften) in Germany from 1996 to 2004, who had contracted urothelial cancer due to occupational exposure, and 196 patients from one Department of Surgery in Dortmund, without known malignancy in their medical history, were genotyped using real-time polymerase chain reaction (PCR) (LightCycler) in relation to GSTP1 A1578G (Ile105Val) polymorphism. Among the subjects with bladder cancer, 46% presented the AA genotype, 39% the AG genotype, and 15% the GG genotype. In the surgical (noncancer) control group analyzed, 42% presented the AA genotype, 42% the AG genotype, and 16% the GG genotype. A subgroup of bladder cancer cases, represented by 46 painters, showed a distribution of 41% of the AA genotype, 48% of the AG genotype, and 11% of the GG genotype. Data indicated that in Caucasians exposed to aromatic amines the GSTP1 A1578G polymorphism did not appear to play a significant role as a predisposing factor for bladder cancer incidence.

  18. Characterization of Intersubunit Communication in the Virginiamycin trans-Acyl Transferase Polyketide Synthase.

    Science.gov (United States)

    Dorival, Jonathan; Annaval, Thibault; Risser, Fanny; Collin, Sabrina; Roblin, Pierre; Jacob, Christophe; Gruez, Arnaud; Chagot, Benjamin; Weissman, Kira J

    2016-03-30

    Modular polyketide synthases (PKSs) direct the biosynthesis of clinically valuable secondary metabolites in bacteria. The fidelity of chain growth depends on specific recognition between successive subunits in each assembly line: interactions mediated by C- and N-terminal "docking domains" (DDs). We have identified a new family of DDs in trans-acyl transferase PKSs, exemplified by a matched pair from the virginiamycin (Vir) system. In the absence of C-terminal partner (VirA (C)DD) or a downstream catalytic domain, the N-terminal DD (VirFG (N)DD) exhibits multiple characteristics of an intrinsically disordered protein. Fusion of the two docking domains results in a stable fold for VirFG (N)DD and an overall protein-protein complex of unique topology whose structure we support by site-directed mutagenesis. Furthermore, using small-angle X-ray scattering (SAXS), the positions of the flanking acyl carrier protein and ketosynthase domains have been identified, allowing modeling of the complete intersubunit interface.

  19. Glutathione S-transferase P influences redox and migration pathways in bone marrow.

    Directory of Open Access Journals (Sweden)

    Jie Zhang

    Full Text Available To interrogate why redox homeostasis and glutathione S-transferase P (GSTP are important in regulating bone marrow cell proliferation and migration, we isolated crude bone marrow, lineage negative and bone marrow derived-dendritic cells (BMDDCs from both wild type (WT and knockout (Gstp1/p2(-/- mice. Comparison of the two strains showed distinct thiol expression patterns. WT had higher baseline and reactive oxygen species-induced levels of S-glutathionylated proteins, some of which (sarco-endoplasmic reticulum Ca2(+-ATPase regulate Ca(2+ fluxes and subsequently influence proliferation and migration. Redox status is also a crucial determinant in the regulation of the chemokine system. CXCL12 chemotactic response was stronger in WT cells, with commensurate alterations in plasma membrane polarization/permeability and intracellular calcium fluxes; activities of the downstream kinases, ERK and Akt were also higher in WT. In addition, expression levels of the chemokine receptor CXCR4 and its associated phosphatase, SHP-2, were higher in WT. Inhibition of CXCR4 or SHP2 decreased the extent of CXCL12-induced migration in WT BMDDCs. The differential surface densities of CXCR4, SHP-2 and inositol trisphosphate receptor in WT and Gstp1/p2(-/- cells correlated with the differential CXCR4 functional activities, as measured by the extent of chemokine-induced directional migration and differences in intracellular signaling. These observed differences contribute to our understanding of how genetic ablation of GSTP causes different levels of myeloproliferation and migration [corrected

  20. Molecular characterization of zeta class glutathione S-transferases from Pinus brutia Ten.

    Indian Academy of Sciences (India)

    E. Oztetik; F. Kockar; M. Alper; M. Iscan

    2015-09-01

    Glutathione transferases (GSTs; EC 2.5.1.18) play important roles in stress tolerance and metabolic detoxification in plants. In higher plants, studies on GSTs have focussed largely on agricultural plants. There is restricted information about molecular characterization of GSTs in gymnosperms. To date, only tau class GST enzymes have been characterized from some pinus species. For the first time, the present study reports cloning and molecular characterization of two zeta class GST genes, namely PbGSTZ1 and PbGSTZ2 from Pinus brutia Ten., which is an economically important pine native to the eastern Mediterranean region and have to cope with several environmental stress conditions. The PbGSTZ1 gene was isolated from cDNA, whereas PbGSTZ2 was isolated from genomic DNA. Sequence analysis of PbGSTZ1 and PbGSTZ2 revealed the presence of an open reading frame of 226 amino acids with typical consensus sequences of the zeta class plant GSTs. Protein and secondary structure prediction analysis of two zeta class PbGSTZs have shared common features of other plant zeta class GSTs. Genomic clone, PbGSTZ2 gene, is unexpectedly intronless. Extensive sequence analysis of PbGSTZ2, with cDNA clone, PbGSTZ1, revealed 87% identity at nucleotide and 81% identity at amino acid levels with 41 amino acids differences suggesting that genomic PbGSTZ2 gene might be an allelic or a paralogue version of PbGSTZ1.

  1. Mitochondrion as a Novel Site of Dichloroacetate Biotransformation by Glutathione Transferase ζ1

    Science.gov (United States)

    Li, Wenjun; McKenzie, Sarah C.; Calcutt, Nigel A.; Liu, Chen; Stacpoole, Peter W.

    2011-01-01

    Dichloroacetate (DCA) is a potential environmental hazard and an investigational drug. Repeated doses of DCA result in reduced drug clearance, probably through inhibition of glutathione transferase ζ1 (GSTZ1), a cytosolic enzyme that converts DCA to glyoxylate. DCA is known to be taken up by mitochondria, where it inhibits pyruvate dehydrogenase kinase, its major pharmacodynamic target. We tested the hypothesis that the mitochondrion was also a site of DCA biotransformation. Immunoreactive GSTZ1 was detected in liver mitochondria from humans and rats, and its identity was confirmed by liquid chromatography/tandem mass spectrometry analysis of the tryptic peptides. Study of rat submitochondrial fractions revealed GSTZ1 to be localized in the mitochondrial matrix. The specific activity of GSTZ1-catalyzed dechlorination of DCA was 2.5- to 3-fold higher in cytosol than in whole mitochondria and was directly proportional to GSTZ1 protein expression in the two compartments. Rat mitochondrial GSTZ1 had a 2.5-fold higher AppKm for glutathione than cytosolic GSTZ1, whereas the AppKm values for DCA were identical. Rats administered DCA at a dose of 500 mg/kg/day for 8 weeks showed reduced hepatic GSTZ1 activity and expression of ∼10% of control levels in both cytosol and mitochondria. We conclude that the mitochondrion is a novel site of DCA biotransformation catalyzed by GSTZ1, an enzyme colocalized in cytosol and mitochondrial matrix. PMID:20884751

  2. Mitochondrion as a novel site of dichloroacetate biotransformation by glutathione transferase zeta 1.

    Science.gov (United States)

    Li, Wenjun; James, Margaret O; McKenzie, Sarah C; Calcutt, Nigel A; Liu, Chen; Stacpoole, Peter W

    2011-01-01

    Dichloroacetate (DCA) is a potential environmental hazard and an investigational drug. Repeated doses of DCA result in reduced drug clearance, probably through inhibition of glutathione transferase ζ1 (GSTZ1), a cytosolic enzyme that converts DCA to glyoxylate. DCA is known to be taken up by mitochondria, where it inhibits pyruvate dehydrogenase kinase, its major pharmacodynamic target. We tested the hypothesis that the mitochondrion was also a site of DCA biotransformation. Immunoreactive GSTZ1 was detected in liver mitochondria from humans and rats, and its identity was confirmed by liquid chromatography/tandem mass spectrometry analysis of the tryptic peptides. Study of rat submitochondrial fractions revealed GSTZ1 to be localized in the mitochondrial matrix. The specific activity of GSTZ1-catalyzed dechlorination of DCA was 2.5- to 3-fold higher in cytosol than in whole mitochondria and was directly proportional to GSTZ1 protein expression in the two compartments. Rat mitochondrial GSTZ1 had a 2.5-fold higher (App)K(m) for glutathione than cytosolic GSTZ1, whereas the (App)K(m) values for DCA were identical. Rats administered DCA at a dose of 500 mg/kg/day for 8 weeks showed reduced hepatic GSTZ1 activity and expression of ∼10% of control levels in both cytosol and mitochondria. We conclude that the mitochondrion is a novel site of DCA biotransformation catalyzed by GSTZ1, an enzyme colocalized in cytosol and mitochondrial matrix.

  3. Immunoprophylactic potential of filarial glutathione-s-transferase in lymphatic filariaisis

    Institute of Scientific and Technical Information of China (English)

    BalM; MandalN; AcharyKG; DasMK; KarSK

    2011-01-01

    Objective:To elucidates the immunoprophylactic potential of glutathion-s-transferase (GST) from cattle filarial parasite Setaria digitata (S. digitata) against lymphatic filariasis. Methods:GST was purified through affinity chromatography (SdGST) and chacterized by SDS-PAGE and Nano-LC MS/MS analysis. Antibody isotypes to SdGST were measured by ELISA. Antibody dependant cellular cytotoxicity (ADCC) was performed in vitro using sera from immunized animals and immune individuals. T-cell proliferation and cytokine response to SdGST in different groups of filariasis were measured. Immunoprophylactic potential of SdGST was evaluate in animal model. Results: SdGST exhibited 30-fold enhancement of enzyme activity over crude parasitic extract. It was found to be 26 kDa by SDS-PAGE. Nano LC-MS/MS analysis followed by blast search showed 100%homology with Dirofilaria immitis (D. immitis) and only 43%with Homo sapiens (H. sapiens). Immunoblotting analysis showed putatively immune individuals carry significant level of antibodies to SdGST as compared with microfilaraemics. Immunized sera and sera endemic normal could neutralize the enzymatic activity of SdGST and inducing in vitro cytotoxicity of microfilariae. Peripheral blood mononuclear cells (PBMC) from endemic normals upon stimulation with SdGST showed a mixed type of Th1/Th2 response. SdGST immunization clear microfilariae from circulation in S. digitata implanted mastomys. Conclusions:The heterologous GST could be potentially developed as a vaccine candidate against lymphatic filarial parasite.

  4. Glutathione s-transferase M1 and T1 genetic polymorphisms in Iranian patients with glaucoma

    Directory of Open Access Journals (Sweden)

    Fatemeh Kazemi Safa

    2014-05-01

    Full Text Available Objective(s:Glaucoma is the second leading cause of blindness and it is related to oxidative stress based on numerous studies. Glutathione S-transferases (GSTs are members of multigenic family, which have important role in cells as an antioxidant. In the present study, we examined the polymorphism of GSTT1 and GSTM1 deletion genotypes (T0M1, T1M0, and T0M0 in 100 Glaucoma patients (41with primary open angle glaucoma (PCAG, and 59 with primary closed angle glaucoma (POAG compared to 100 healthy subjects. Materials and Methods: GSTM1and GSTT1 polymorphisms were determined by multiplex polymerase chain reaction. Results: GSTM1 and GSTT1 null deletions genotypes were determined in 22 (53.7% and 7 (17.1% patients with PCAG and 34 (34% and 15 (15% in healthy subjects[VAIO1] . Comparison between patients and healthy subjects regarding GSTM1 and GSTT1 genotypes revealed increase of GSTM1 null deletions genotypes in patients with PCAG (P=0.03. Conclusion: It was concluded that the increased frequencies of GSTM1 null in patients with PCAG could be a risk factor for incidence of PCAG in the Iranian population.  

  5. Activation of Variants of Hypoxanthine-Guanine Phosphoribosyl Transferase by the Normal Enzyme

    Science.gov (United States)

    Bakay, Bohdan; Nyhan, William L.

    1972-01-01

    Deficient hypoxanthine-guanine phosphoribosyl transferase (HGPRT; EC 2.4.2.8) enzymes from erythrocytes of patients with hyperuricemia and with the Lesch-Nyhan syndrome migrate 15% faster in polyacrylamide gel disc electrophoresis than the normal enzyme. A half-sister of two males with partial deficiency, who had 34% of normal HGPRT activity in her erythrocytes, yielded profiles containing two distinct zones of activity; one corresponded to the enzyme found in normal individuals and one to the variant of her half-brothers. However, in her profile her variant enzyme showed notably greater activity than that observed in her half-brothers. This increase was due to an activation of the variant by normal enzyme. Electrophoresis of mixtures of normal enzyme with partially deficient enzymes from patients with hyperuricemia and with the Lesch-Nyhan syndrome also led to activation of deficient HGPRT variants by normal enzymes. Deficient variants were also activated by normal enzyme on filtration through Sephadex G-25. Experiments in which deficient variant enzymes were activated with purified normal enzyme labeled with 125I indicated that deficient enzymes incorporate components of the normal enzyme. No such activation of deficient enzymes was ever obtained when mixtures of deficient and normal enzymes were put together in a test tube. Images PMID:4341698

  6. Differential expression of two glutathione S-transferases identified from the American dog tick, Dermacentor variabilis.

    Science.gov (United States)

    Dreher-Lesnick, S M; Mulenga, A; Simser, J A; Azad, A F

    2006-08-01

    Reciprocal signalling and gene expression play a cardinal role during pathogen-host molecular interactions and are prerequisite to the maintenance of balanced homeostasis. Gene expression repertoire changes during rickettsial infection and glutathione-S-transferases (GSTs) were among the genes found up-regulated in Rickettsia-infected Dermacentor variabilis. GSTs are well known to play an important part in cellular stress responses in the host. We have cloned two full-length GSTs from D. variabilis (DvGST1 and DvGST2). Comparison of these two DvGST molecules with those of other species indicate that DvGST1 is related to the mammalian class theta and insect class delta GSTs, while DvGST2 does not seem to fall in the same family. Northern blotting analyses revealed differential expression patterns, where DvGST1 and DvGST2 transcripts are found in the tick gut, with DvGST2 transcripts also present in the ovaries. Both DvGST transcripts are up-regulated upon tick feeding. Challenge of fed adult ticks with Escherichia coli injection showed decreased transcript amounts compared with ticks injected with phosphate-buffered saline (sham) and naïve ticks.

  7. Expression of Candida albicans glutathione transferases is induced inside phagocytes and upon diverse environmental stresses.

    Science.gov (United States)

    Garcerá, Ana; Casas, Celia; Herrero, Enrique

    2010-06-01

    Candida albicans has four ORFs for glutathione transferases (GSTs) of the GTT classes, and another one coding for an Omega class member. Under laboratory conditions, only GTT11 (GTT1/2 class) and GTO1 (Omega class) are expressed significantly in exponentially growing cells, particularly when these are subjected to diverse environmental stresses, including oxidative stress. They also become transitorily upregulated at the early stationary phase. Accordingly, the levels of the CaGto1 and CaGtt11 proteins increase after treatment with oxidants and upon osmotic stress, in addition to the early stationary phase. GTT11 and GTO1 transcription shows a complex dependence on the Hog1 and Cap1 factors upon different stresses. Purified CaGtt11 and CaGto1 proteins display enzyme activities similar to the Saccharomyces cerevisiae homologues. Thus, CaGtt11 has activity against standard GST substrates and is also active as peroxidase, while CaGto1 displays thiol oxidoreductase and dehydroascorbate reductase activities. Fluorescence microscopy and subfractionation studies indicate that CaGto1 is cytosolic, while CaGtt11 is associated with a particulate fraction. Under ex vivo conditions, CaGto1 and CaGtt11 become transitorily upregulated inside macrophages and neutrophils. Under these conditions, the promoter of GTT14 (GTT1/2 class) also becomes activated. These observations point to the importance of C. albicans GSTs in the defence against phagocytes.

  8. Synthesis and characterization of a series of highly fluorogenic substrates for glutathione transferases, a general strategy.

    Science.gov (United States)

    Zhang, Jie; Shibata, Aya; Ito, Mika; Shuto, Satoshi; Ito, Yoshihiro; Mannervik, Bengt; Abe, Hiroshi; Morgenstern, Ralf

    2011-09-07

    Glutathione transferases (GSTs) are used in biotechnology applications as fusion partners for facile purification and are also overexpressed in certain tumors. Consequently, there is a need for sensitive detection of the enzymes. Here we describe a general strategy for the synthesis and characterization of novel fluorogenic substrates for GSTs. The substrates were synthesized by introducing an electrophilic sulfonamide linkage to fluorescent molecules containing an amino group [e.g., 2,4-dinitrobenzenesulfonamide (DNs) derivatives of coumarin, cresyl violet, and rhodamine]. The derivatives were essentially nonfluorescent, and upon GST catalyzed cleavage of the dinitrobenzenesulfonamide, free fluorophore is released (and 1-glutathionyl-2,4-dinitrobenzene + SO(2)). All the coumarin-, cresyl violet- and rhodamine-based fluorogenic probes turned out to be good substrates for most GSTs, especially for GSTA(1-1), in terms of strong fluorescence increases (71-1200-fold), high k(cat)/K(m) values (10(4)-10(7) M(-1) s(-1)) and significant rate enhancements (10(6)-10(9)-fold). The substrates were successfully applied to quantitate very low levels of GST activity in cell extracts and DNs-cresyl violet was also successfully applied to the imaging of microsomal MGST(1) activity in living cells. The cresyl violet stained cells retained their fluorescence after fixation, which is a very useful property. In summary, we describe a general and versatile strategy to generate fluorogenic GST substrates, some of them providing the most sensitive assays so far described for GSTs.

  9. Developmental studies on the Sigma and Delta-1 glutathione transferases of Lucilia cuprina.

    Science.gov (United States)

    Pal, Ramavati; Sanil, Nitasha; Clark, Alan

    2012-03-01

    The glutathione transferases (GSTs) are a large group of enzymes having both detoxication roles and specialist metabolic functions. The present work represents an initial approach to identifying some of these roles by examining the variation of specific members of the family under differing conditions. The GSTs from Lucilia cuprina have been partially purified, members of two families being isolated, by the use of glutathione immobilised on epichlorhydrin-activated Sepharose 6B. The GSTs were separated by 2D SDS-PAGE and characterised by MALDI-TOF analysis of tryptic peptides. The mass fragments were then matched against the corresponding Drosophila melanogaster and Musca domestica sequences. GSTs were identified as coming from only the Sigma and Delta classes. The multiple Delta zones appear all to be derived from the Lucilia GSTD1 isoform. The distribution of these GST proteins has been studied during different developmental stages of the insect. Delta isoforms were present in all developmental stages of L. cuprina. The Sigma GST was not detectable in the egg, was just detectable in the larval and pupal stages and was the major GST isolated in the adult. Sigma and Delta isoforms were both found in all body segments of the insect. Both isoforms appear to undergo extensive post-translational modification. Activities of the two types of protein with model substrates have been determined.

  10. Diverging catalytic capacities and selectivity profiles with haloalkane substrates of chimeric alpha class glutathione transferases.

    Science.gov (United States)

    Kurtovic, Sanela; Shokeer, Abeer; Mannervik, Bengt

    2008-05-01

    Six homologous Alpha class glutathione transferases of human, bovine, and rat origins were hybridized by means of DNA shuffling. The chimeric mutants were compared with the parental enzymes in their activities with several alkyl iodides. In order to facilitate a multivariate analysis of relationships between substrates and enzyme activities, three descriptors were introduced: 'specific catalytic capacity', 'substrate selectivity', and 'unit-scaled substrate selectivity'. In some cases the purified mutants showed higher specific activity with a certain alkyl iodide than any of the parental enzymes. However, the overriding effect of DNA shuffling was the generation of chimeras with altered substrate selectivity profiles and catalytic capacities. The altered substrate selectivity profiles of some mutants could be rationalized by changes of the substrate-binding residues in the active site of the enzyme. However, in four of the isolated mutants all active-site residues were found identical with those of rat GST A2-2, even though their substrate specificity profiles were significantly different. Clearly, amino acid residues distant from first-sphere interactions with the substrate influence the catalytic activity. These results are relevant both to the understanding how functional properties may develop in natural enzyme evolution and in the tailoring of novel functions in protein engineering.

  11. Glutathione transferases from Anguilla anguilla liver: identification, cloning and functional characterization.

    Science.gov (United States)

    Carletti, Erminia; Sulpizio, Marilisa; Bucciarelli, Tonino; Del Boccio, Piero; Federici, Luca; Di Ilio, Carmine

    2008-10-20

    Glutathione transferases (GSTs) constitute a class of detoxifying enzymes involved in Phase II metabolism. Using GSH-affinity chromatografy followed by HPLC analysis, two GST isoforms were isolated from the Anguilla anguilla liver cytosol. The major GST belongs to the piscine-specific rho class and accounted for about 59% of total GST affinity eluted fraction, while the remaining 41% was represented by a Pi class GST. Both isoforms were cloned, heterologously expressed in Escherichia coli and their enzyme activities were characterized with respect to a broad spectrum of well-known GST substrates. Our data indicate that only a fraction of prototypical GST substrates are conjugated by these enzymes and that Pi class GST has higher specific activity than rho class GST against 1-chloro-2,4-dinitrobenzene (CDNB), ethracrynic acid, 4-nitroquinoline-1-oxide and p-nitrophenyl acetate while trans-2-nonenal is detoxified more efficiently by rho class GST. Analysis of the kinetics parameters of the conjugation against CDNB indicated that the utilization ratio K(cat)/K(m) is slightly higher for rho class GST with respect to pi class GSTs. Finally, to determine the potential for environmental inhibition of the GST isoforms, we examined the effect of the widely used herbicide atrazine as an inhibitor of catalytic activity. The inhibition studies revealed that atrazine was an effective inhibitor of GST-CDNB catalytic activities of both isoforms at micromolar concentrations, suggesting the sensitivity of these isoforms to pesticide inhibition at environmentally relevant concentrations.

  12. Effect of acaricides on the activity of glutathione transferases from the parasitic mite Sarcoptes scabiei.

    Science.gov (United States)

    Molin, E U; Mattsson, J G

    2008-01-01

    Glutathione transferases (GSTs) are a family of multifunctional enzymes with fundamental roles in cellular detoxication. Here we report the molecular characterization of 3 recombinant GSTs belonging to the mu- and delta-class from the parasitic mite Sarcoptes scabiei. Kinetic constants were determined, and the effect of acaricides, including organothiophosphates, pyrethroid esters, a formamidine, a macrocyclic lactone, an organochlorine as well as a bridged diphenyl acaricide, on the activity of the GSTs were tested using 1-chloro-2,4-dinitrobenzene (CDNB) as model substrate. Our results showed that enzymes from the same class and with high amino acid sequence identity have significantly different kinetic properties. For instance, one mu-class GST lost more than 50% of its activity in the presence of one of the organothiophosphates while the activity of the second mu-class GST was only slightly reduced under identical conditions. Tertiary structure modulations indicated that structural differences were the crucial factor for the different kinetic patterns observed. Genome analysis showed that the two mu-class GSTs are organized in tandem in the S. scabiei genome. Taken together these results show that GSTs might be involved in the metabolism of acaricides in S. scabiei.

  13. Distribution of glutathione transferases in Gram-positive bacteria and Archaea.

    Science.gov (United States)

    Allocati, Nerino; Federici, Luca; Masulli, Michele; Di Ilio, Carmine

    2012-03-01

    Glutathione transferases (GSTs) have been widely studied in Gram-negative bacteria and the structure and function of several representatives have been elucidated. Conversely, limited information is available about the occurrence, classification and functional features of GSTs both in Gram-positive bacteria and in Archaea. An analysis of 305 fully-sequenced Gram-positive genomes highlights the presence of 49 putative GST genes in the genera of both Firmicutes and Actinobacteria phyla. We also performed an analysis on 81 complete genomes of the Archaea domain. Eleven hits were found in the Halobacteriaceae family of the Euryarchaeota phylum and only one in the Crenarchaeota phylum. A comparison of the identified sequences with well-characterized GSTs belonging to both Gram-negative and eukaryotic GSTs sheds light on their putative function and the evolutionary relationships within the large GST superfamily. This analysis suggests that the identified sequences mainly cluster in the new Xi class, while Beta class GSTs, widely distributed in Gram-negative bacteria, are under-represented in Gram-positive bacteria and absent in Archaea.

  14. Quantitative and selective polymerase chain reaction analysis of highly similar human alpha-class glutathione transferases.

    Science.gov (United States)

    Larsson, Emilia; Mannervik, Bengt; Raffalli-Mathieu, Françoise

    2011-05-01

    Alpha-class glutathione transferases (GSTs) found expressed in human tissues constitute a family of four homologous enzymes with contrasting enzyme activities. In particular, GST A3-3 has been shown to contribute to the biosynthesis of steroid hormones in human cells and is selectively expressed in steroidogenic tissues. The more ubiquitous GST A1-1, GST A2-2, and GST A4-4 appear to be primarily involved in detoxification processes and are expressed at higher levels than GST A3-3. We are interested in studying the cell and tissue expression of the GST A3-3 gene, yet the existence of highly expressed sequence-similar homologs and of several splice variants is a serious challenge for the specific detection of unique transcript species. We found that published polymerase chain reaction (PCR) primers for GST A3-3 lack the specificity required for reliable quantitative analysis. Therefore, we designed quantitative PCR (qPCR) primers with greatly increased discrimination power for the human GSTA3 full-length transcript. The improved primers allow accurate discrimination between GST A3-3 and the other alpha-class GSTs and so are of great value to studies of the expression of the GSTA3 gene. The novel primers were used to quantify GSTA3 transcripts in human embryonic liver and steroidogenic cell lines.

  15. Structure, function and disease relevance of Omega-class glutathione transferases.

    Science.gov (United States)

    Board, Philip G; Menon, Deepthi

    2016-05-01

    The Omega-class cytosolic glutathione transferases (GSTs) have distinct structural and functional attributes that allow them to perform novel roles unrelated to the functions of other GSTs. Mammalian GSTO1-1 has been found to play a previously unappreciated role in the glutathionylation cycle that is emerging as significant mechanism regulating protein function. GSTO1-1-catalyzed glutathionylation or deglutathionylation of a key signaling protein may explain the requirement for catalytically active GSTO1-1 in LPS-stimulated pro-inflammatory signaling through the TLR4 receptor. The observation that ML175 a specific GSTO1-1 inhibitor can block LPS-stimulated inflammatory signaling has opened a new avenue for the development of novel anti-inflammatory drugs that could be useful in the treatment of toxic shock and other inflammatory disorders. The role of GSTO2-2 remains unclear. As a dehydroascorbate reductase, it could contribute to the maintenance of cellular redox balance and it is interesting to note that the GSTO2 N142D polymorphism has been associated with multiple diseases including Alzheimer's disease, Parkinson's disease, familial amyotrophic lateral sclerosis, chronic obstructive pulmonary disease, age-related cataract and breast cancer.

  16. Identification of novel glutathione transferases in Echinococcus granulosus. An evolutionary perspective.

    Science.gov (United States)

    Iriarte, Andrés; Arbildi, Paula; La-Rocca, Silvana; Musto, Héctor; Fernández, Verónica

    2012-09-01

    Glutathione transferase enzymes (GSTs) constitute a major detoxification system in helminth parasites and have been related to the modulation of host immune response mechanisms. At least three different GSTs classes have been described in Platyhelminthes: Mu, Sigma and Omega. Mining the genome of Echinococcus multilocularis and the ESTs databases of Taenia solium and E. granulosus identified two new GSTs from the cestode E. granulosus, named EgGST2 and EgGST3. It also revealed that the Omega class of GSTs was absent from the Taenidae family. EgGST2 and EgGST3 are actively expressed in the parasite. In order to know the origin of these new GSTs, in silico analyses were performed. While EgGST2 is classified as belonging to the Sigma class, the data obtained for EgGST3 allowed a less clear interpretation. The study of the evolutionary relatedness based on the C-terminal domain sequence, gene structure conservation and three-dimensional structure predictions, suggests that EgGST3 is derived from the Platyhelminthes' Sigma-class cluster. Interestingly, the N-terminal domain displays some characteristic Omega-class residues, including a Cys residue that is likely to be involved in the catalytic mechanism. We discuss different evolutionary scenarios that could explain the observed patterns.

  17. Selective binding of glutathione conjugates of fatty acid derivatives by plant glutathione transferases.

    Science.gov (United States)

    Dixon, David P; Edwards, Robert

    2009-08-07

    Proteomic studies with Arabidopsis thaliana have revealed that the plant-specific Tau (U) class glutathione transferases (GSTs) are selectively retained by S-hexylglutathione affinity supports. Overexpression of members of the Arabidopsis GST superfamily in Escherichia coli showed that 25 of the complement of 28 GSTUs caused the aberrant accumulation of acylated glutathione thioesters in vivo, a perturbation that was not observed with other GST classes. Each GSTU caused a specific group of fatty acyl derivatives to accumulate, which varied in chain length (C(6) to C(18)), additional oxygen content (0 or 1), and desaturation (0 or 1). Thioesters bound tightly to recombinant GSTs (K(d) approximately 1 microm), explaining their accumulation. Transient expression of GSTUs in Nicotiana benthamiana followed by recovery by Strep-tag affinity chromatography allowed the respective plant ligands to be extracted and characterized. Again, each GST showed a distinct profile of recovered metabolites, notably glutathionylated oxophytodienoic acid and related oxygenated fatty acids. Similarly, the expression of the major Tau protein GSTU19 in the endogenous host Arabidopsis led to the selective binding of the glutathionylated oxophytodienoic acid-glutathione conjugate, with the enzyme able to catalyze the conjugation reaction. Additional ligands identified in planta included other fatty acid derivatives including divinyl ethers and glutathionylated chlorogenic acid. The strong and specific retention of various oxygenated fatty acids by each GSTU and the conservation in binding observed in the different hosts suggest that these proteins have selective roles in binding and conjugating these unstable metabolites in vivo.

  18. Structural insights into the dehydroascorbate reductase activity of human omega-class glutathione transferases.

    Science.gov (United States)

    Zhou, Huina; Brock, Joseph; Liu, Dan; Board, Philip G; Oakley, Aaron J

    2012-07-13

    The reduction of dehydroascorbate (DHA) to ascorbic acid (AA) is a vital cellular function. The omega-class glutathione transferases (GSTs) catalyze several reductive reactions in cellular biochemistry, including DHA reduction. In humans, two isozymes (GSTO1-1 and GSTO2-2) with significant DHA reductase (DHAR) activity are found, sharing 64% sequence identity. While the activity of GSTO2-2 is higher, it is significantly more unstable in vitro. We report the first crystal structures of human GSTO2-2, stabilized through site-directed mutagenesis and determined at 1.9 Å resolution in the presence and absence of glutathione (GSH). The structure of a human GSTO1-1 has been determined at 1.7 Å resolution in complex with the reaction product AA, which unexpectedly binds in the G-site, where the glutamyl moiety of GSH binds. The structure suggests a similar mode of ascorbate binding in GSTO2-2. This is the first time that a non-GSH-based reaction product has been observed in the G-site of any GST. AA stacks against a conserved aromatic residue, F34 (equivalent to Y34 in GSTO2-2). Mutation of Y34 to alanine in GSTO2-2 eliminates DHAR activity. From these structures and other biochemical data, we propose a mechanism of substrate binding and catalysis of DHAR activity.

  19. Preliminary studies on the renaturation of denatured catfish (Clarias gariepinus) glutathione transferase.

    Science.gov (United States)

    Ojopagogo, Yetunde Adedolapo; Adewale, Isaac Olusanjo; Afolayan, Adeyinka

    2013-12-01

    Purified juvenile catfish (Clarias gariepinus) glutathione transferase (cgGST) was denatured in vitro and renatured in the absence and presence of different concentrations of endogenous or xenobiotic model substrates. Protein transitions during unfolding and refolding were monitored by activity measurement as well as changes in protein conformation using UV difference spectra at 230 nm. Gdn-HCl at 0.22 M caused 50 % inactivation of the enzyme and at 1.1 M, the enzyme was completely unfolded. Refolding of cgGST main isozyme was not completely reversible at higher concentrations of Gdn-HCl and is dependent on protein concentration. An enzyme concentration of 30 μg/ml yielded 40 % percentage residual activity in the presence of glutathione (GSH), regardless of the concentration that was present as opposed to 30 % obtained in its absence. The xenobiotic model substrate, lindane, appears to have no effect on the refolding of the enzyme. In summary, our results show that GSH assists in the refolding of cgGST in a concentration-independent manner and may be involved in the same function in vivo whereas the xenobiotic model substrate does not.

  20. Glutathione S-Transferase Ω 1 variation does not influence age at onset of Huntington's disease

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    Saft Carsten

    2004-03-01

    Full Text Available Abstract Background Huntington's disease (HD is a fully penetrant, autosomal dominantly inherited disorder associated with abnormal expansions of a stretch of perfect CAG repeats in the 5' part of the IT15 gene. The number of repeat units is highly predictive for the age at onset (AO of the disorder. But AO is only modestly correlated with repeat length when intermediate HD expansions are considered. Circumstantial evidence suggests that additional features of the HD course are based on genetic traits. Therefore, it may be possible to investigate the genetic background of HD, i.e. to map the loci underlying the development and progression of the disease. Recently an association of Glutathione S-Transferase Ω 1 (GSTO1 and possibly of GSTO2 with AO was demonstrated for, both, Alzheimer's (AD and Parkinson's disease (PD. Methods We have genotyped the polymorphisms rs4925 GSTO1 and rs2297235 GSTO2 in 232 patients with HD and 228 controls. Results After genotyping GSTO1 and GSTO2 polymorphisms, firstly there was no statistically significant difference in AO for HD patients, as well as secondly for HD patients vs. controls concerning, both, genotype and allele frequencies, respectively. Conclusion The GSTO1 and GSTO2 genes flanked by the investigated polymorphisms are not comprised in a primary candidate region influencing AO in HD.

  1. Evaluation of gamma gluthamyl transferase and uric acid levels in arsenic exposed subject

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    Ceylan Bal

    2015-06-01

    Full Text Available Objective: Arsenic is a metal with a widespread industrial usage and causing oxidative stress. Studies shows serum uric acid and gamma gluthamyl transferase (GGT levels are increasing in oxidative stress. The aim of this study is to evaluate the effect of arsenic exposure on serum uric acid and GGT levels. Methods: 500 patients who refer to Ankara Occupational Disease Hospital between 2010 to 2014 for periodic examination and urinary arsenic, serum uric acid and serum GGT levels assessed are included in this study. 268 patients with urinary arsenic levels over 35μg/L are defined as exposed and below 35μg/L are controls. Results: Data of 500 patients were analysed. 268 of them had high urine arsenic levels and 232 had normal urine arsenic levels. In the high urine arsenic level group the median serum uric acid level was 5.4 (2.60-7.20 and median serum GGT level was 27 (10-51 in the other group with normal urine arsenic levels the median serum uric acid level was 4.9 (2.5-7 and median serum GGT level was 22 (10-52. The difference between two groups was statistically significant (p value: 0.002 and <0.001 respectively Conclusion: Arsenic exposure may be associated with hyperuricemia and high levels of GGT and with prospective studies the causal relationship between arsenic exposure and hyperuricemia and GGT can be revealed.

  2. Association between herbivore stress and glutathione S-transferase expression in Pinus brutia Ten.

    Science.gov (United States)

    Semiz, A; Çelik-Turgut, G; Semiz, G; Özgün, Ö; Şen, A

    2016-03-31

    Plants have developed mechanisms to defend themselves against many factors including biotic stress such as herbivores and pathogens. Glutathione S-transferase (GST) is a glutathione-dependent detoxifying enzyme and plays critical roles in stress tolerance and detoxification metabolism in plants. Pinus brutia Ten. is a prominent native forest tree species in Turkey, due to both its economic and ecological assets. One of the problems faced by P. brutia afforestation sites is the attacks by pine processionary moth (Thaumetopoea wilkinsoni Tams.). In this study, we investigated the changes in activity and mRNA expression of GST in pine samples taken from both resistant and susceptible clones against T. wilkinsoni over a nine month period in a clonal seed orchard. It was found that the average cytosolic GST activities of trees in March and July were significantly higher than the values obtained in November. November was considered to be the control since trees were not under stress yet. In addition, RT-PCR results clearly showed that levels of GST transcripts in March and July samples were significantly higher as compared to the level seen in November. These findings strongly suggest that GST activity from P. brutia would be a valuable marker for exposure to herbivory stress.

  3. Novel class of glutathione transferases from cyanobacteria exhibit high catalytic activities towards naturally occurring isothiocyanates

    Science.gov (United States)

    Wiktelius, Eric; Stenberg, Gun

    2007-01-01

    In the present paper, we report a novel class of GSTs (glutathione transferases), called the Chi class, originating from cyanobacteria and with properties not observed previously in prokaryotic enzymes. GSTs constitute a widespread multifunctional group of proteins, of which mammalian enzymes are the best characterized. Although GSTs have their origin in prokaryotes, few bacterial representatives have been characterized in detail, and the catalytic activities and substrate specificities observed have generally been very modest. The few well-studied bacterial GSTs have largely unknown physiological functions. Genome databases reveal that cyanobacteria have an extensive arsenal of glutathione-associated proteins. We have studied two cyanobacterial GSTs which are the first examples of bacterial enzymes that are as catalytically efficient as the best mammalian enzymes. GSTs from the thermophile Thermosynechococcus elongatus BP-1 and from Synechococcus elongatus PCC 6301 were found to catalyse the conjugation of naturally occurring plant-derived isothiocyanates to glutathione at high rates. The cyanobacterial GSTs studied are smaller than previously described members of this enzyme family, but display many of the typical structural features that are characteristics of GSTs. They are also active towards several classical substrates, but at the same moderate rates that have been observed for other GSTs derived from prokaryotes. The cloning, expression and characterization of two cyanobacterial GSTs are described. The possible significance of the observed catalytic properties is discussed in the context of physiological relevance and GST evolution. PMID:17484723

  4. Erythrocyte glutathione transferase: a general probe for chemical contaminations in mammals

    Science.gov (United States)

    Bocedi, A; Fabrini, R; Lai, O; Alfieri, L; Roncoroni, C; Noce, A; Pedersen, JZ; Ricci, G

    2016-01-01

    Glutathione transferases (GSTs) are enzymes devoted to the protection of cells against many different toxins. In erythrocytes, the isoenzyme (e-GST) mainly present is GSTP1-1, which is overexpressed in humans in case of increased blood toxicity, as it occurs in nephrophatic patients or in healthy subjects living in polluted areas. The present study explores the possibility that e-GST may be used as an innovative and highly sensitive biomarker of blood toxicity also for other mammals. All distinct e-GSTs from humans, Bos taurus (cow), Sus scrofa (pig), Capra hircus (goat), Equus caballus (horse), Equus asinus (donkey) and Ovis aries (sheep), show very similar amino acid sequences, identical kinetics and stability properties. Reference values for e-GST in all these mammals reared in controlled farms span from 3.5±0.2 U/gHb in the pig to 17.0±0.9 U/gHb in goat; such activity levels can easily be determined with high precision using only a few microliters of whole blood and a simple spectrophotometric assay. Possibly disturbing factors have been examined to avoid artifact determinations. This study provides the basis for future screening studies to verify if animals have been exposed to toxicologic insults. Preliminary data on cows reared in polluted areas show increased expression of e-GST, which parallels the results found for humans. PMID:27551520

  5. Sfp-type 4'-phosphopantetheinyl transferase is indispensable for fungal pathogenicity.

    Science.gov (United States)

    Horbach, Ralf; Graf, Alexander; Weihmann, Fabian; Antelo, Luis; Mathea, Sebastian; Liermann, Johannes C; Opatz, Till; Thines, Eckhard; Aguirre, Jesús; Deising, Holger B

    2009-10-01

    In filamentous fungi, Sfp-type 4'-phosphopantetheinyl transferases (PPTases) activate enzymes involved in primary (alpha-aminoadipate reductase [AAR]) and secondary (polyketide synthases and nonribosomal peptide synthetases) metabolism. We cloned the PPTase gene PPT1 of the maize anthracnose fungus Colletotrichum graminicola and generated PPTase-deficient mutants (Deltappt1). Deltappt1 strains were auxotrophic for Lys, unable to synthesize siderophores, hypersensitive to reactive oxygen species, and unable to synthesize polyketides (PKs). A differential analysis of secondary metabolites produced by wild-type and Deltappt1 strains led to the identification of six novel PKs. Infection-related morphogenesis was affected in Deltappt1 strains. Rarely formed appressoria of Deltappt1 strains were nonmelanized and ruptured on intact plant. The hyphae of Deltappt1 strains colonized wounded maize (Zea mays) leaves but failed to generate necrotic anthracnose disease symptoms and were defective in asexual sporulation. To analyze the pleiotropic pathogenicity phenotype, we generated AAR-deficient mutants (Deltaaar1) and employed a melanin-deficient mutant (M1.502). Results indicated that PPT1 activates enzymes required at defined stages of infection. Melanization is required for cell wall rigidity and appressorium function, and Lys supplied by the AAR1 pathway is essential for necrotrophic development. As PPTase-deficient mutants of Magnaporthe oryzea were also nonpathogenic, we conclude that PPTases represent a novel fungal pathogenicity factor.

  6. Biochemical characterization and distribution of glutathione S-transferases in leaping mullet (Liza saliens).

    Science.gov (United States)

    Sen, A; Kirikbakan, A

    2004-09-01

    In this study, feral leaping mullet (Liza saliens) liver cytosolic glutathione S-transferases (GSTs) were investigated and characterized using 1-chloro-2,4-dinitrobenzene (CDNB) and ethacrynic acid (EA) as substrates. The average GST activities towards CDNB and EA were found to be 1365 +/- 41 and 140 +/- 20 nmol/min per mg protein, respectively. The effects of cytosolic protein amount and temperature ranging from 4 to 70 degrees C on enzyme activities were examined. While both activities towards CDNB and EA showed similar dependence on protein amount, temperature optima were found as 37 and 42 degrees C, respectively. In addition, the effects of pH on GST-CDNB and -EA activities were studied and different pH activity profiles were observed. For both substrates, GST activities were found to obey Michaelis-Menten kinetics with apparent V(max) and K(m) values of 1661 nmol/min per mg protein and 0.24 mM and 157 nmol/min per mg protein and 0.056 mM for CDNB and EA, respectively. Distribution of GST in Liza saliens tissues was investigated and compared with other fish species. Very high GST activities were measured in tissues from Liza saliens such as liver, kidney, testis, proximal intestine, and gills. Moreover, our results suggested that GST activities from Liza saliens would be a valuable biomarker for aquatic pollution.

  7. Purification and Identification of Glutathione S-transferase in Rice Root under Cadmium Stress

    Institute of Scientific and Technical Information of China (English)

    ZHANG Chun-hua; WU Ze-ying; JU Ting; GE Ying

    2013-01-01

    Cadmium (Cd) contamination in paddy soils poses a serious threat to the production and quality of rice.Among various biochemical processes related to Cd detoxification in rice,glutathione S-transferase (GST) plays an important role,catalyzing Cd complexation with glutathione (GSH) and scavenging reactive oxygen species (ROS) in cells.In this study,a hydroponic experiment was conducted to investigate the response of GST isozymes in rice roots upon Cd exposure.Results showed that the GST activity in rice roots was clearly enhanced by 50 μmol/L Cd treatment for 7 d.The GST isozymes were purified by ammonium sulphate precipitation,gel filtration chromatography and affinity chromatography.After being separated by SDS-PAGE and visualized by silver staining,GSTU6 was identified by in-gel digestion,MALDI-TOF-MS analysis and peptide mass fingerprint.The results confirm the vital function of tau class rice GST in Cd detoxification.

  8. Genetic Variations of Glutathione S-Transferase Influence on Blood Cadmium Concentration

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    Nitchaphat Khansakorn

    2012-01-01

    Full Text Available The glutathione S-transferases (GSTs are involved in biotransformation and detoxification of cadmium (Cd. Genetic polymorphisms in these genes may lead to interindividual variation in Cd susceptibility. The objective of this study was to assess the association of GSTs (GSTT1, GSTM1, and GSTP1 Val105Ile polymorphisms with blood Cd concentrations in a nonoccupationally exposed population. The 370 blood samples were analyzed for Cd concentration and polymorphisms in GSTs genes. Geometric mean of blood Cd among this population was 0.46±0.02 μg/L (with 95% CI; 0.43–0.49 μg/L. Blood Cd concentrations in subjects carrying GSTP1 Val/Val genotype were significantly higher than those with Ile/Ile and Ile/Val genotypes. No significant differences in blood Cd concentrations among individual with gene deletions of GSTT1 and GSTM1 were observed. GSTP1/GSTT1 and GSTP1/GSTM1 combinations showed significantly associated with increase in blood Cd levels. This study indicated that polymorphisms of GSTP1 combined with GSTT1 and/or GSTM1 deletion are likely to influence on individual susceptibility to cadmium toxicity.

  9. Mice deficient in dihydrolipoyl succinyl transferase show increased vulnerability to mitochondrial toxins.

    Science.gov (United States)

    Yang, Lichuan; Shi, Qingli; Ho, Daniel J; Starkov, Anatoly A; Wille, Elizabeth J; Xu, Hui; Chen, H L; Zhang, Steven; Stack, Cliona M; Calingasan, Noel Y; Gibson, Gary E; Beal, M Flint

    2009-11-01

    The activity of a key mitochondrial tricarboxylic acid cycle enzyme, alpha-ketoglutarate dehydrogenase complex (KGDHC), declines in many neurodegenerative diseases. KGDHC consists of three subunits. The dihydrolipoyl succinyl transferase (DLST) component is unique to KGDHC. DLST(+/-) mice showed reduced mRNA and protein levels and decreased brain mitochondrial KGDHC activity. Neurotoxic effects of mitochondrial toxins were exacerbated in DLST(+/-) mice. MPTP produced a significantly greater reduction of striatal dopamine and tyrosine hydroxylase-positive neurons in the substantia nigra pars compacta of DLST(+/-) mice. DLST deficiency enhanced the severity of lipid peroxidation in the substantia nigra after MPTP treatment. Striatal lesions induced by either malonate or 3-nitropropionic acid (3-NP) were significantly larger in DLST(+/-) mice than in wildtype controls. DLST deficiency enhanced the 3-NP inhibition of mitochondria enzymes, and 3-NP induced protein and DNA oxidations. These observations support the hypothesis that reductions in KGDHC may impair the adaptability of the brain and contribute to the pathogenesis of neurodegenerative diseases.

  10. Characterization of recombinant human nicotinamide mononucleotide adenylyl transferase (NMNAT), a nuclear enzyme essential for NAD synthesis.

    Science.gov (United States)

    Schweiger, M; Hennig, K; Lerner, F; Niere, M; Hirsch-Kauffmann, M; Specht, T; Weise, C; Oei, S L; Ziegler, M

    2001-03-09

    Nicotinamide mononucleotide adenylyl transferase (NMNAT) is an essential enzyme in all organisms, because it catalyzes a key step of NAD synthesis. However, little is known about the structure and regulation of this enzyme. In this study we established the primary structure of human NMNAT. The human sequence represents the first report of the primary structure of this enzyme for an organism higher than yeast. The enzyme was purified from human placenta and internal peptide sequences determined. Analysis of human DNA sequence data then permitted the cloning of a cDNA encoding this enzyme. Recombinant NMNAT exhibited catalytic properties similar to the originally purified enzyme. Human NMNAT (molecular weight 31932) consists of 279 amino acids and exhibits substantial structural differences to the enzymes from lower organisms. A putative nuclear localization signal was confirmed by immunofluorescence studies. NMNAT strongly inhibited recombinant human poly(ADP-ribose) polymerase 1, however, NMNAT was not modified by poly(ADP-ribose). NMNAT appears to be a substrate of nuclear kinases and contains at least three potential phosphorylation sites. Endogenous and recombinant NMNAT were phosphorylated in nuclear extracts in the presence of [gamma-(32)P]ATP. We propose that NMNAT's activity or interaction with nuclear proteins are likely to be modulated by phosphorylation.

  11. Population pharmacokinetics of melphalan and glutathione S-transferase polymorphisms in relation to side effects.

    Science.gov (United States)

    Kühne, A; Sezer, O; Heider, U; Meineke, I; Muhlke, S; Niere, W; Overbeck, T; Hohloch, K; Trümper, L; Brockmöller, J; Kaiser, R

    2008-05-01

    Melphalan is associated with severe side effects such as mucositis, diarrhea, and myelosuppression. We investigated how much the individual severity of these side effects is predicted by pharmacokinetics. In addition, we studied glutathione S-transferase GSTM1, GSTT1, and GSTP1 polymorphisms in relation to adverse events. A high interindividual pharmacokinetic variability was observed in 84 patients. There was a linear correlation between creatinine and melphalan clearance (P=0.0004). Patients treated with a dose > or = 70 mg/m(2) had a 23-fold increased risk to develop mucositis (P<0.001) and a 12-fold increased risk to develop diarrhea (P<0.001) compared with lower doses. The GSTP1 codon 105 polymorphism may be relevant for development of mucositis and the GSTT1 deletion may predict diarrhea, but these findings require confirmation. Melphalan-induced side effects were significantly dependent only on dose. Therapeutic drug monitoring or genotyping for GST does not appear to be very helpful in optimizing therapy with melphalan.

  12. Association study of Glutathione S-Transferase polymorphisms and risk of endometriosis in an Iranian population

    Science.gov (United States)

    Hassani, Mina; Saliminejad, Kioomars; Heidarizadeh, Masood; Kamali, Koorosh; Memariani, Toktam; Khorram Khorshid, Hamid Reza

    2016-01-01

    Background: Endometriosis influenced by both genetic and environmental factors. Associations of glutathione S-transferases (GSTs) genes polymorphisms in endometriosis have been investigated by various researchers; however, the results are not consistent. Objective: We examined the associations of GSTM1 and GSTT1 null genotypes and GSTP1 313 A/G polymorphisms with endometriosis in an Iranian population. Materials and Methods: In this case-control study, 151 women with diagnosis of endometriosis and 156 normal healthy women as control group were included. The genotyping was determined using multiplex PCR and PCR- RFLP methods. Results: The GSTM1 null genotype was significantly higher (p=0.027) in the cases (7.3%) than the control group (1.3%). There was no significant difference between the frequency of GSTT1 genotypes between the cases and controls. The GSTP1 313 AG genotype was significantly lower (p=0.048) in the case (33.1%) than the control group (44.4%). Conclusion: Our results showed that GSTM1 and GSTP1 polymorphisms may be associated with susceptibility of endometriosis in Iranian women. PMID:27351025

  13. Transcriptional Responses of Glutathione Transferase Genes in Ruditapes philippinarum Exposed to Microcystin-LR

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    Bruno Reis

    2015-04-01

    Full Text Available Glutathione Transferases (GSTs are phase II detoxification enzymes known to be involved in the molecular response against microcystins (MCs induced toxicity. However, the individual role of the several GST isoforms in the MC detoxification process is still unknown. In this study, the time-dependent changes on gene expression of several GST isoforms (pi, mu, sigma 1, sigma 2 in parallel with enzymatic activity of total GST were investigated in gills and hepatopancreas of the bivalve Ruditapes philippinarum exposed to pure MC-LR (10 and 100 µg/L. No significant changes in GST enzyme activities were found on both organs. In contrast, MC-LR affected the transcriptional activities of these detoxification enzymes both in gills and hepatopancreas. GST transcriptional changes in gills promoted by MC-LR were characterized by an early (12 h induction of mu and sigma 1 transcripts. On the other hand, the GST transcriptional changes in hepatopancreas were characterized by a later induction (48 h of mu transcript, but also by an early inhibition (6 h of the four transcripts. The different transcription patterns obtained for the tested GST isoforms in this study highlight the potential divergent physiological roles played by these isoenzymes during the detoxification of MC-LR.

  14. Ablation of Arg-tRNA-protein transferases results in defective neural tube development.

    Science.gov (United States)

    Kim, Eunkyoung; Kim, Seonmu; Lee, Jung Hoon; Kwon, Yong Tae; Lee, Min Jae

    2016-08-01

    The arginylation branch of the N-end rule pathway is a ubiquitin-mediated proteolytic system in which post-translational conjugation of Arg by ATE1-encoded Arg-tRNA-protein transferase to N-terminal Asp, Glu, or oxidized Cys residues generates essential degradation signals. Here, we characterized the ATE1-/- mice and identified the essential role of N-terminal arginylation in neural tube development. ATE1-null mice showed severe intracerebral hemorrhages and cystic space near the neural tubes. Expression of ATE1 was prominent in the developing brain and spinal cord, and this pattern overlapped with the migration path of neural stem cells. The ATE1-/- brain showed defective G-protein signaling. Finally, we observed reduced mitosis in ATE1-/- neuroepithelium and a significantly higher nitric oxide concentration in the ATE1-/- brain. Our results strongly suggest that the crucial role of ATE1 in neural tube development is directly related to proper turn-over of the RGS4 protein, which participate in the oxygen-sensing mechanism in the cells. [BMB Reports 2016; 49(8): 443-448].

  15. Biochemical analysis of a recombinant glutathione transferase from the cestode Echinococcus granulosus.

    Science.gov (United States)

    Harispe, Laura; García, Gabriela; Arbildi, Paula; Pascovich, Leticia; Chalar, Cora; Zaha, Arnaldo; Fernandez, Cecilia; Fernandez, Veronica

    2010-04-01

    Glutathione transferases (GSTs) are believed to be a major detoxification system in helminths. We describe the expression and functional analysis of EgGST, a cytosolic GST from Echinococcus granulosus, related to the Mu-class of mammalian enzymes. EgGST was produced as an enzymatically active dimeric protein (rEgGST), with highest specific activity towards the standard substrate 1-chloro-2,4-dinitrobenzene (CDNB; 2.5 micromol min(-1)mg(-1)), followed by ethacrynic acid. Interestingly, rEgGST displayed glutathione peroxidase activity (towards cumene hydroperoxide), and conjugated reactive carbonyls (trans-2-nonenal and trans,trans-2,4-decadienal), indicating that it may intercept damaging products of lipid peroxidation. In addition, classical GST inhibitors (cybacron blue, triphenylthin chloride and ellagic acid) and a number of anthelmintic drugs (mainly, hexachlorophene and rafoxanide) were found to interfere with glutathione-conjugation to CDNB; suggesting that they may bind to EgGST. Considered globally, the functional properties of rEgGST are similar to those of putative orthologs from Echinococcus multilcularis and Taenia solium, the other medically important cestodes. Interestingly, our results also indicate that differences exist between these closely related cestode GSTs, which probably reflect specific biological functions of the molecules in each parasitic organism.

  16. Optical biosensor consisting of glutathione-S-transferase for detection of captan.

    Science.gov (United States)

    Choi, Jeong-Woo; Kim, Young-Kee; Song, Sun-Young; Lee, In-ho; Lee, Won-Hong

    2003-10-15

    The optical biosensor consisting of a glutathione-S-transferase (GST)-immobilized gel film was developed to detect captan in contaminated water. The sensing scheme was based on the decrease of yellow product, s-(2,4-dinitrobenzene) glutathione, produced from substrates, 1-chloro-2,4-dinitrobenzene (CDNB) and glutathione (GSH), due to the inhibition of GST reaction by captan. Absorbance of the product as the output of enzyme reaction was detected and the light was guided through the optical fibers. The enzyme reactor of the sensor system was fabricated by the gel entrapment technique for the immobilized GST film. The immobilized GST had the maximum activity at pH 6.5. The optimal concentrations of substrates were determined with 1 mM for both of CDNB and GSH. The optimum concentration of enzyme was also determined with 100 microg/ml. The activity of immobilized enzyme was fairly sustained during 30 days. The proposed biosensor could successfully detect the captan up to 2 ppm and the response time to steady signal was about 15 min.

  17. Studies on interactions between plant secondary metabolites and glutathione transferase using fluorescence quenching method.

    Science.gov (United States)

    Zhang, Xian; Cheng, Xinsheng; Wang, Chuanqin; Xue, Zechun; Yang, Liwen; Xi, Zheng

    2007-04-01

    The interactions between plant secondary metabolites (tannic acid, rutin, cinnamic acid and catechin) and glutathione transferase (GST) were investigated by fluorescence and UV-Vis absorption spectroscopy. Intrinsic fluorescence of GST was measured by selectively exciting their tryptophan (Trp) residues and quenching constants were determined using the Stern-Volmer equation. The binding affinity was found to be strongest for tannic acid and ranked in the order tannic acid>rutin>cinnamic acid>catechin. The pH values in the range of 6.7-7.9, except for tannic acid, did not affect significantly the affinity of rutin, cinnamic acid and catechin with GST. Results showed that the fluorescence quenching of GST was a static_quenching. Fluorescence quenching and UV-Vis absorption spectroscopy suggested that only the tannic acid changed the microenvironment of the Trp residues. Furthermore, the number of binding sites and binding constants at different pH values showed that tannic acid had strongest affinity towards GST and hydrogen bonding played an important role in the affinity between GST and the metabolites.

  18. Effects of Catechol O-Methyl Transferase Inhibition on Anti-Inflammatory Activity of Luteolin Metabolites.

    Science.gov (United States)

    Ha, Sang Keun; Lee, Jin-Ah; Cho, Eun Jung; Choi, Inwook

    2017-02-01

    Although luteolin is known to have potent anti-inflammatory activities, much less information has been provided on such activities of its hepatic metabolites. Luteolin was subjected to hepatic metabolism in HepG2 cells either without or with catechol O-methyl transferase (COMT) inhibitor. To identify hepatic metabolites of luteolin without (luteolin metabolites, LMs) or with COMT inhibitor (LMs+CI), metabolites were treated by β-glucuronidase and sulfatase, and found that they were composed of glucuronide and sulfate conjugates of diosmetin in LMs or these conjugates of luteolin in LMs+CI. LMs and LMs+CI were examined for their anti-inflammatory activities on LPS stimulated Raw 264.7 cells. Expression of iNOS and production of nitric oxide and pro-inflammatory cytokines such as TNF-α, IL-1β, and IL-6 were suppressed more effectively by the treatment with LMs+CI than LMs. Our data provide a new insight on possible improvement in functional properties of luteolin on target cells by modifying their metabolic pathway in hepatocytes.

  19. Role of Carnitine Acetyl Transferase in Regulation of Nitric Oxide Signaling in Pulmonary Arterial Endothelial Cells

    Directory of Open Access Journals (Sweden)

    Stephen M. Black

    2012-12-01

    Full Text Available Congenital heart defects with increased pulmonary blood flow (PBF result in pulmonary endothelial dysfunction that is dependent, at least in part, on decreases in nitric oxide (NO signaling. Utilizing a lamb model with left-to-right shunting of blood and increased PBF that mimics the human disease, we have recently shown that a disruption in carnitine homeostasis, due to a decreased carnitine acetyl transferase (CrAT activity, correlates with decreased bioavailable NO. Thus, we undertook this study to test the hypothesis that the CrAT enzyme plays a major role in regulating NO signaling through its effect on mitochondrial function. We utilized the siRNA gene knockdown approach to mimic the effect of decreased CrAT activity in pulmonary arterial endothelial cells (PAEC. Our data indicate that silencing the CrAT gene disrupted cellular carnitine homeostasis, reduced the expression of mitochondrial superoxide dismutase-and resulted in an increase in oxidative stress within the mitochondrion. CrAT gene silencing also disrupted mitochondrial bioenergetics resulting in reduced ATP generation and decreased NO signaling secondary to a reduction in eNOS/Hsp90 interactions. Thus, this study links the disruption of carnitine homeostasis to the loss of NO signaling observed in children with CHD. Preserving carnitine homeostasis may have important clinical implications that warrant further investigation.

  20. Antioxidant Effect of Selenium-containing Glutathione S-Transferase in Rat Cardiomyocytes

    Institute of Scientific and Technical Information of China (English)

    YIN Li; HAN Xiao; YU Yang; GUO Xiao; REN Li-qun; FANG Jing-qi; LIU Zhi-yi; YAN Gang-lin; WEI Jing-yan

    2012-01-01

    As one of the most important antioxidant enzymes,glutathione peroxidase(GPX) protects cells and tissues from oxidative damage,and plays an important role in cardiovascular and cerebrovascular injuries induced by oxidative stress.The antioxidant effect of selenium-containing glutathione S-transferase(Se-GST),a mimic of GPX was investigated on rat cardiomyocytes.To explore the protection function of Se-GST in hydrogen peroxide(H2O2) challenged rat cardiomyocytes,we examined malondialdehyde(MDA),lactate dehydrogenase(LDH),superoxide dismutase(SOD) and cell apoptosis.The results demonstrate exposure of rat cardiomyocytes to H2O2 for 6 and 12 h induced the significant increases of MDA,LDH and apoptosis rate of cardiomyocytes,but pretreatment of rat cardiomyocytes with Se-GST at 0.0005 or 0.001 unit/mL prevents oxidative stress induced by H2O2 with the decreases of cell apoptosis.All the results him Se-GST has antioxidant activity for oxidative stress challenged rat cardiomyocytes.

  1. Expression profiling of selected glutathione transferase genes in Zea mays (L.) seedlings infested with cereal aphids.

    Science.gov (United States)

    Sytykiewicz, Hubert; Chrzanowski, Grzegorz; Czerniewicz, Paweł; Sprawka, Iwona; Łukasik, Iwona; Goławska, Sylwia; Sempruch, Cezary

    2014-01-01

    The purpose of this report was to evaluate the expression patterns of selected glutathione transferase genes (gst1, gst18, gst23 and gst24) in the tissues of two maize (Zea mays L.) varieties (relatively resistant Ambrozja and susceptible Tasty Sweet) that were colonized with oligophagous bird cherry-oat aphid (Rhopalosiphum padi L.) or monophagous grain aphid (Sitobion avenae L.). Simultaneously, insect-triggered generation of superoxide anion radicals (O2•-) in infested Z. mays plants was monitored. Quantified parameters were measured at 1, 2, 4, 8, 24, 48 and 72 h post-initial aphid infestation (hpi) in relation to the non-infested control seedlings. Significant increases in gst transcript amounts were recorded in aphid-stressed plants in comparison to the control seedlings. Maximal enhancement in the expression of the gst genes in aphid-attacked maize plants was found at 8 hpi (gst23) or 24 hpi (gst1, gst18 and gst24) compared to the control. Investigated Z. mays cultivars formed excessive superoxide anion radicals in response to insect treatments, and the highest overproduction of O2•- was noted 4 or 8 h after infestation, depending on the aphid treatment and maize genotype. Importantly, the Ambrozja variety could be characterized as having more profound increments in the levels of gst transcript abundance and O2•- generation in comparison with the Tasty Sweet genotype.

  2. A test for adequate wastewater treatment based on glutathione S transferase isoenzyme profile.

    Science.gov (United States)

    Grammou, A; Samaras, P; Papadimitriou, C; Papadopoulos, A I

    2013-04-01

    Discharge to the environment of treated or non-treated municipal wastewater imposes several threats to coastal and estuarine ecosystems which are difficult to assess. In our study we evaluate the use of the isoenzyme profile of glutathione S transferase (GST) in combination with the kinetic characteristics of the whole enzyme and of heme peroxidase, as a test of adequate treatment of municipal wastewater. For this reason, Artemia nauplii were incubated in artificial seawater prepared by wastewater samples, such as secondary municipal effluents produced by a conventional activated sludge unit and advanced treated effluents produced by the employment of coagulation, activated carbon adsorption and chlorination as single processes or as combined ones. Characteristic changes of the isoenzyme pattern and the enzymes' kinetic properties were caused by chlorinated secondary municipal effluent or by secondary non-chlorinated effluent. Advanced treatment by combination of coagulation and/or carbon adsorption resulted to less prominent changes, suggesting more adequate treatment. Our results suggest that GST isoenzyme profile in combination with the kinetic properties of the total enzyme family is a sensitive test for the evaluation of the adequateness of the treatment of reclaimed wastewater and the reduction of potentially harmful compounds. Potentially, it may offer a 'fingerprint' characteristic of a particular effluent and probably of the treatment level it has been subjected.

  3. Purification and characterization of a glutathione S-transferase from Mucor mucedo.

    Science.gov (United States)

    Hamed, Ragaa R; Abu-Shady, Mohamed R; El-Beih, Fawkia M; Abdalla, Abdel-Monem A; Afifi, Ola M

    2005-01-01

    An intracellular glutathione transferase was purified to homogenity from the fungus, Mucor mucedo, using DEAE-cellulose ion-exchange and glutathione affinity chromatography. Gel filtration chromatography and SDS-PAGE revealed that the purified GST is a homodimer with approximate native and subunit molecular mass of 53 kDa and 23.4 kDa, respectively. The enzyme has a pI value of 4.8, a pH optimum at pH 8.0 and apparent activation energy (Ea) of 1.42 kcal mol(-1). The purified GST acts readily on CDNB with almost negligible peroxidase activity and the activity was inhibited by Cibacron Blue (IC50 0.252 microM) and hematin (IC50 3.55 microM). M. mucedo GST displayed a non-Michaelian behavior. At low (0.1-0.3 mM) and high (0.3-2 mM) substrate concentration, Km (GSH) was calculated to be 0.179 and 0.65 mM, whereas Km(CDNB) was 0.531 and 11 mM and k(cat) was 39.8 and 552 s(-1), respectively. The enzyme showed apparent pKa values of 6-6.5 and 8.0.

  4. Sulphonamide-based bombesin prodrug analogues for glutathione transferase, useful in targeted cancer chemotherapy.

    Science.gov (United States)

    Axarli, I; Labrou, N E; Petrou, C; Rassias, N; Cordopatis, P; Clonis, Y D

    2009-05-01

    Glutathione transferases (GSTs) are enzymes involved in cellular detoxification by catalysing the nucleophilic attack of glutathione (GSH) on the electrophilic centre of a number of toxic compounds and xenobiotics, including certain chemotherapeutic drugs. The encountered chemotherapeutic resistant of tumour cells, thus, has been associated with the increase of total GST expression. GSTs, in addition to GSH-conjugating activity, exhibit sulphonamidase activity, catalyzing the GSH-mediated hydrolysis of sulphonamide bonds. Such reactions are of interest as potential tumour-directed prodrug activation strategies. In the present work we report the design and synthesis of novel chimaeric sulphonamide derivatives of bombesin, able to be activated by the model human isoenzyme GSTA1-1 (hGSTA1-1). These derivatives bear a peptidyl-moiety (analogues of bombesin peptide: R-[Lue(13)]-bombesin, R-[Phe(13)]-bombesin and R-[Ser(3),Arg(10),Phe(13)]-bombesin, where R=C(6)H(5)SO(2)NH-) as molecular recognition element for targeting the drug selectively to tumour cells. The released S-alkyl-glutathione, after hGSTA1-1-mediated cleavage of the sulphonamide bond, provides an inhibitor of varied strength against GSTs from different sources. These prodrugs are envisaged as a plausible means to sensitize drug-resistant tumours that overexpress GSTs.

  5. Cefadroxil potency as cancer co-therapy candidate by glutathione s-transferase mechanism

    Directory of Open Access Journals (Sweden)

    Tri Yuliani

    2013-03-01

    Full Text Available Background: Glutathione S-transferases (GSTs havean important role in the detoxification of electrophiles,such as some anticancer drugs. Compounds with phenolicand/or α,b-unsaturated carbonyl group have been knownas GSTs inhibitor in vitro. Cefadroxil in vitro decreasedGST-Pi activity but not GSTs in rat kidney cytosol.GST inhibitor in a specific organ and of a specific classis needed for safety in cancer chemotherapy. The studyaims to observe the effect of cefadroxil on GSTs in vivoin rat kidney cytosol and then compare it to those seenfor liver, lung, and spleen in vivo.Methods: Cefadroxil was given twice a day byforcefeeding for five days. Rat kidney cytosol was thenprepared and its protein concentration was determined.Cytosolic total GST, GST-Mu and GST-Pi activitieswere monitored by a continuous spectrophotometricmethod using the following substrates: 1-chloro,2,4-dinitrobenzene (CDNB (non-specific substrate,1,2-dichloro-4-nitrobenzene (DCNB for GST-Mu, andethacrynic acid (EA for GST-Pi.Results: The data showed that cefadroxil significantlyincreased the activity of GSTs, GST-Mu, and GSTPiin rat kidney cytosol (8.75%, 47.81%, and 6.67%respectively.Conclusion: Cefadroxil did not inhibit GSTs, GST-Mu,and GST-Pi in rat kidney in vivo indicating that it doesnot inhibit chemotherapy detoxification by GSTs, GSTMu,and GST-Pi in normal kidney cells.

  6. Gamma-Glutamyl Transferase Levels in Patients with Acute Ischemic Stroke

    Directory of Open Access Journals (Sweden)

    Nurbanu Gurbuzer

    2014-01-01

    Full Text Available Objective. The aim of this study was to investigate the relationship between gamma-glutamyl transferase (GGT levels, cerebrovascular risk factors, and distribution of cerebral infarct areas in patients with acute ischemic stroke (AIS. Patients and Methods. Sixty patients with AIS and 44 controls who had not cerebrovascular disease were included in the study. The patients were divided into four groups according to the location of the infarct area and evaluated as for GGT levels and the presence of diabetes mellitus (DM, hypertension (HT, and hyperlipidemia (HL. Results. The frequency of DM, HT, and HL and gender distributions were similar. The mean GGT levels were significantly higher in patients with AIS and those with relatively larger areas of infarction (P<0.05. Increased mean GGT levels were found in the subgroup with hypertension, higher LDL-cholesterol, and triglyceride levels among cases with AIS (P<0.05. Conclusion. Higher GGT levels in AIS patients reinforce the relationship of GGT with inflammation and oxidative stress. The observation of higher GGT levels in patients with relatively larger areas of infarction is indicative of a positive correlation between increases in infarct areas and elevated GGT levels.

  7. Functional Identification of Proteus mirabilis eptC Gene Encoding a Core Lipopolysaccharide Phosphoethanolamine Transferase

    Directory of Open Access Journals (Sweden)

    Eleonora Aquilini

    2014-04-01

    Full Text Available By comparison of the Proteus mirabilis HI4320 genome with known lipopolysaccharide (LPS phosphoethanolamine transferases, three putative candidates (PMI3040, PMI3576, and PMI3104 were identified. One of them, eptC (PMI3104 was able to modify the LPS of two defined non-polar core LPS mutants of Klebsiella pneumoniae that we use as surrogate substrates. Mass spectrometry and nuclear magnetic resonance showed that eptC directs the incorporation of phosphoethanolamine to the O-6 of l-glycero-d-mano-heptose II. The eptC gene is found in all the P. mirabilis strains analyzed in this study. Putative eptC homologues were found for only two additional genera of the Enterobacteriaceae family, Photobacterium and Providencia. The data obtained in this work supports the role of the eptC (PMI3104 product in the transfer of PEtN to the O-6 of l,d-HepII in P. mirabilis strains.

  8. Analysis of gene polymorphic variants of angiotensinconverting enzyme, glutathione S-transferase in cardiomyopathy sick patients

    Directory of Open Access Journals (Sweden)

    Arvid R. Berg

    2012-12-01

    Full Text Available Cardiomyopathies (CMP are considered diseases with unknown etiology. CMP are usually diagnosed on the late stages of the disease. It is an important task to seek methods which allow diagnosing CMP on the early stages of development. Aim – to estimate the type of polymorphic variants of angiotensin converting enzyme (ACE, glutathione S-transferase (GSTM1 frequency distribution among the CMP sick and healthy individuals living in the Republic of Bashkortostan, and to substantiate their role in the CMP pathogenesis. Material and Methods – There were 67 CMP sick put under observation. Out of them40 werediagnosed ischemic cardiomyopathy (ICM, and 27 were diagnosed dilated cardiomyopathy (DCM. The control group was made up of 110 practically healthy people. The results.In the ICM sick group the DD genotype (χ2=4.8; p=0.029 was definitely found more frequently, also in case of DCM the increase of DD genotype (χ2=4.0, p=0.044 frequency was ascertained. Conclusion – The genetic analysis of polymorphic locus of I/D ACE gene in the ICM and DCM sick showed decrease in frequency of occurrence II, ID genotypes, I allele and increase of D genotype and D allele which points out the increased risk of these cardiovascular diseases.

  9. Phenylalanine-induced leucopenia in genetic and dichloroacetic acid generated deficiency of glutathione transferase Zeta.

    Science.gov (United States)

    Theodoratos, Angelo; Tu, Wen Juan; Cappello, Jean; Blackburn, Anneke C; Matthaei, Klaus; Board, Philip G

    2009-04-15

    Glutathione transferase Zeta (GSTZ1-1) is identical to maleylacetoacetate isomerase and catalyses a significant step in the catabolism of phenylalanine and tyrosine. Exposure of GSTZ1-1 deficient mice to high dietary phenylalanine causes a rapid loss of circulating white blood cells (WBCs). The loss was significant (P<0.05) after 2 days and total WBCs were reduced by 60% after 6 days. The rapid loss of WBCs was attributed to the accumulation of the catabolic intermediates maleylacetoacetate or maleylacetone (MA) in the circulation. Serum from GSTZ1-1 deficient mice treated with phenylalanine was cytotoxic to splenocytes from normal BALB/c mice and direct incubation of normal splenocytes with MA caused a rapid loss of viability. Dichloroacetic acid (DCA) has been used therapeutically to treat lactic acidosis and is potentially of use in cancer chemotherapy. Since DCA can inactivate GSTZ1-1 there is a possibility that long-term treatment of patients with DCA could cause GSTZ1-1 deficiency and susceptibility to oxidative stress and phenylalanine/tyrosine-induced WBC loss. However, although we found that DCA at 200mg/(kg day) causes a severe loss of hepatic GSTZ1-1 activity in BALB/c mice, it did not induce WBC cytotoxicity when combined with high dietary phenylalanine.

  10. Measurement of mouse liver glutathione S-transferase activity by the integrated method

    Institute of Scientific and Technical Information of China (English)

    廖飞; 李甲初; 康格非; 曾昭淳; 左渝萍

    2003-01-01

    Objective: The integrated method was investigated to measure Vm/Km of mouse liver glutathione S-transferase (GST) activity on GSH and 7-Cl-4-nitrobenzofurazozan. Methods: Presetting concentration of one substrate twenty-fold above the others and taking maximum product absorbance Am as parameter while Km as constant, Vm/Km was obtained by nonlinear fitting of GST reaction curve to the integrated Michaelis-Menten equation ln [Am/(Am-Ai)]+Ai/(ε×Km)=(Vm/Km)×ti (1). Results: Vm/Km for GST showed slight dependence on initial substrate concentration and data range, but it was resistant to background absorbance, error in reaction origin and small deviation in presetting Km. Vm/Km was proportional to the amount of GST with upper limit higher than that by initial rate. There was close correlation between Vm/Km and initial rate of the same GST. Consistent results were obtained by this integrated method and classical initial rate method for the measurement of mouse liver GST. Conclusion: With the concentration of one substrate twenty-fold above the others, this integrated method was reliable to measure the activity of enzyme on two substrates, and substrate concentration of the lower one close to its apparent Km was able to be used.

  11. Probiotics and oral health

    OpenAIRE

    Rastogi, Pavitra; Saini, Himani; Dixit, Jaya; Singhal, Rameshwari

    2011-01-01

    Probiotics utilize the naturally occurring bacteria to confer health benefits. Traditionally, probiotics have been associated with gut health, and are being mainly utilized for prevention or treatment of gastrointestinal infections and disease; however, recently, several studies have suggested the use of probiotics for oral health purposes. The aim of this review is to understand the potential mechanism of action of probiotic bacteria in the oral cavity and summarize their observed effects wi...

  12. Oral Somatosensory Awareness

    OpenAIRE

    De Boer, L. L.

    2014-01-01

    Oral somatosensory awareness refers to the somatic sensations arising within the mouth, and to the information these sensations provide about the state and structure of the mouth itself, and objects in the mouth. Because the oral tissues have a strong somatosensory innervation, they are the locus of some of our most intense and vivid bodily experiences. The salient pain of toothache, or the habit of running one's tongue over one's teeth when someone mentions "dentist", provide two very differ...

  13. Oral and esophageal disorders.

    Science.gov (United States)

    Noyer, C M; Simon, D

    1997-06-01

    This article focused on the approach to oral and esophageal disorders in patients with AIDS. Most of these disorders respond to various therapeutic regimens. Some of the oral complications can be prevented with dental prophylaxis, whereas recurrent esophageal disease in some patients may require long-term suppressive therapy. As patients with AIDS live longer with lower CD4 counts, gastroenterologists need to become familiar with the approach to and management of the more common lesions of the mouth and esophagus.

  14. Oral pigmentation: A review.

    Science.gov (United States)

    Sreeja, C; Ramakrishnan, K; Vijayalakshmi, D; Devi, M; Aesha, I; Vijayabanu, B

    2015-08-01

    Pigmentations are commonly found in the mouth. They represent in various clinical patterns that can range from just physiologic changes to oral manifestations of systemic diseases and malignancies. Color changes in the oral mucosa can be attributed to the deposition of either endogenous or exogenous pigments as a result of various mucosal diseases. The various pigmentations can be in the form of blue/purple vascular lesions, brown melanotic lesions, brown heme-associated lesions, gray/black pigmentations.

  15. ON ORAL CANCER

    Directory of Open Access Journals (Sweden)

    P. V. Svetitsky

    2012-01-01

    Full Text Available The paper analyzes a rise in the incidence of oral cancer in the Rostov Region since the 1990s. The study has indicated that this rise is associated with regional population growth due to the forced migrants after the collapse of the USSR. Financial problems, unbalanced nutrition, poor oral hygiene, and depression in this group of patients have contributed to the higher incidence of precancers and cancers.

  16. Maintaining women's oral health.

    Science.gov (United States)

    McCann, A L; Bonci, L

    2001-07-01

    Women must adopt health-promoting strategies for both general health and the oral cavity, because the health of a woman's body and oral cavity are bidirectional. For general health-maintenance strategies, dental practitioners should actively advise women to minimize alcohol use, abstain from or cease smoking, stay physically active, and choose the right foods to nourish both the body and mind. For oral health-maintenance strategies, dental practitioners should advise women on how to prevent or control oral infections, particularly dental caries and periodontal diseases. Specifically, women need to know how to remove plaque from the teeth mechanically, use appropriate chemotherapeutic agents and dentifrices, use oral irrigation, and control halitosis. Dental practitioners also need to stress the importance of regular maintenance visits for disease prevention. Adolescent women are more prone to gingivitis and aphthous ulcers when they begin their menstrual cycles and need advice about cessation of tobacco use, mouth protection during athletic activities, cleaning orthodontic appliances, developing good dietary habits, and avoiding eating disorders. Women in early to middle adulthood may be pregnant or using oral contraceptives with concomitant changes in oral tissues. Dental practitioners need to advise them how to take care of the oral cavity during these changes and how to promote the health of their infants, including good nutrition. Older women experience the onset of menopause and increased vulnerability to osteoporosis. They may also experience xerostomia and burning mouth syndrome. Dental practitioners need to help women alleviate these symptoms and encourage them to continue good infection control and diet practices.

  17. Oral vs. salivary diagnostics

    Science.gov (United States)

    Marques, Joana; Corby, Patricia M.; Barber, Cheryl A.; Abrams, William R.; Malamud, Daniel

    2015-05-01

    The field of "salivary diagnostics" includes studies utilizing samples obtained from a variety of sources within the oral cavity. These samples include; whole unstimulated saliva, stimulated whole saliva, duct saliva collected directly from the parotid, submandibular/sublingual glands or minor salivary glands, swabs of the buccal mucosa, tongue or tonsils, and gingival crevicular fluid. Many publications state "we collected saliva from subjects" without fully describing the process or source of the oral fluid. Factors that need to be documented in any study include the time of day of the collection, the method used to stimulate and collect the fluid, and how much fluid is being collected and for how long. The handling of the oral fluid during and post-collection is also critical and may include addition of protease or nuclease inhibitors, centrifugation, and cold or frozen storage prior to assay. In an effort to create a standard protocol for determining a biomarker's origin we carried out a pilot study collecting oral fluid from 5 different sites in the mouth and monitoring the concentrations of pro- and anti-inflammatory cytokines detected using MesoScaleDiscovery (MSD) electrochemiluminesence assays. Our data suggested that 3 of the cytokines are primarily derived from the submandibular gland, while 7 of the cytokines come from a source other than the major salivary glands such as the minor salivary glands or cells in the oral mucosae. Here we review the literature on monitoring biomarkers in oral samples and stress the need for determining the blood/saliva ratio when a quantitative determination is needed and suggest that the term oral diagnostic be used if the source of an analyte in the oral cavity is unknown.

  18. Effects of glutathione S-transferase M1 and T1 deletions on epilepsy risk among a Tunisian population.

    Science.gov (United States)

    Chbili, Chahra; B'chir, Fatma; Ben Fredj, Maha; Saguem, Bochra-Nourhène; Ben Amor, Sana; Ben Ammou, Sofiene; Saguem, Saad

    2014-09-01

    Glutathione-S-transferases enzymes are involved in the detoxification of several endogenous and exogenous substances. In this present study, we evaluated the effects of two glutathione-S-transferase polymorphisms, (GSTM1 and GSTT1) on epilepsy risk susceptibility in a Tunisian population. These polymorphisms were analyzed in 229 healthy subjects and 98 patients with epilepsy, using a polymerase chain reaction (PCR). Odds ratio (ORs) was used for analyzing results. The study results demonstrated that individuals with the GSTM1 null genotype were at an increased risk of developing epilepsy [OR=3.80, 95% confidence interval (CI) (2.15-4.78)], whereas no significant effects were observed between individuals with GSTT1 null genotype and epilepsy risk [OR=1.15, 95% CI (0.62-2.12)]. These genotyping finding revealed that the absence of GSTM1 activity could be contributor factor for the development of epilepsy disease.

  19. Action of glycosyl transferases upon "Bombay" (Oh) erythrocytes. Conversion to cells showing blood-group H and A specificities.

    Science.gov (United States)

    Schenkel-Brunner, H; Prohaska, R; Tuppy, H

    1975-08-15

    Individuals of the rare "Bombay" (Oh) blood-group phenotype lacking, due to a genetic defect, the alpha(1-2)fucosyl transferase, which is responsible for converting blood-group H precursor substances to H-specific structures. Treatment with GDP-fucose and alpha(1-2)fucosyl transferase prepared from gastric mucosa of O individuals to transform native or ficin-treated "Bombay" erythrocytes into cells phenotypically resembling O cells. The transformation was achieved, however, after prior incubation of the "Bombay" erythrocytes with neuraminidase, indicating that blood-group H precursor molecules on the surface of these cells are masked by sialyl residues. Blood-group A specificity was conferred upon neuraminidase-treated "Bombay" cells by enzymatic transfer of alpha-N-acetylgalactosamine residues, in addition to alpha-fucose residues.

  20. Oral and systemic photoprotection.

    Science.gov (United States)

    Chen, Andrew C; Damian, Diona L; Halliday, Gary M

    2014-01-01

    Photoprotection can be provided not only by ultraviolet (UV) blockers but also by oral substances. Epidemiologically identified associations between foods and skin cancer and interventional experiments have discovered mechanisms of UV skin damage. These approaches have identified oral substances that are photoprotective in humans. UV inhibits adenosine triphosphate (ATP) production causing an energy crisis, which prevents optimal skin immunity and DNA repair. Enhancing ATP production with oral nicotinamide protects from UV immunosuppression, enhances DNA repair and reduces skin cancer in humans. Reactive oxygen species also contribute to photodamage. Nontoxic substances consumed in the diet, or available as oral supplements, can protect the skin by multiple potential mechanisms. These substances include polyphenols in fruit, vegetables, wine, tea and caffeine-containing foods. UV-induced prostaglandin E2 (PGE2 ) contributes to photodamage. Nonsteroidal anti-inflammatory drugs and food substances reduce production of this lipid mediator. Fish oils are photoprotective, at least partially by reducing PGE2 . Orally consumed substances, either in the diet or as supplements, can influence cutaneous responses to UV. A current research goal is to develop an oral supplement that could be used in conjunction with other sun protective strategies in order to provide improved protection from sunlight.

  1. Melatonin and oral cavity.

    Science.gov (United States)

    Cengiz, Murat İnanç; Cengiz, Seda; Wang, Hom-Lay

    2012-01-01

    While initially the oral cavity was considered to be mainly a source of various bacteria, their toxins and antigens, recent studies showed that it may also be a location of oxidative stress and periodontal inflammation. Accordingly, this paper focuses on the involvement of melatonin in oxidative stress diseases of oral cavity as well as on potential therapeutic implications of melatonin in dental disorders. Melatonin has immunomodulatory and antioxidant activities, stimulates the proliferation of collagen and osseous tissue, and acts as a protector against cellular degeneration associated with aging and toxin exposure. Arising out of its antioxidant actions, melatonin protects against inflammatory processes and cellular damage caused by the toxic derivates of oxygen. As a result of these actions, melatonin may be useful as a coadjuvant in the treatment of certain conditions of the oral cavity. However, the most important effect of melatonin seems to result from its potent antioxidant, immunomodulatory, protective, and anticancer properties. Thus, melatonin could be used therapeutically for instance, locally, in the oral cavity damage of mechanical, bacterial, fungal, or viral origin, in postsurgical wounds caused by tooth extractions and other oral surgeries. Additionally, it can help bone formation in various autoimmunological disorders such as Sjorgen syndrome, in periodontal diseases, in toxic effects of dental materials, in dental implants, and in oral cancers.

  2. Melatonin and Oral Cavity

    Directory of Open Access Journals (Sweden)

    Murat İnanç Cengiz

    2012-01-01

    Full Text Available While initially the oral cavity was considered to be mainly a source of various bacteria, their toxins and antigens, recent studies showed that it may also be a location of oxidative stress and periodontal inflammation. Accordingly, this paper focuses on the involvement of melatonin in oxidative stress diseases of oral cavity as well as on potential therapeutic implications of melatonin in dental disorders. Melatonin has immunomodulatory and antioxidant activities, stimulates the proliferation of collagen and osseous tissue, and acts as a protector against cellular degeneration associated with aging and toxin exposure. Arising out of its antioxidant actions, melatonin protects against inflammatory processes and cellular damage caused by the toxic derivates of oxygen. As a result of these actions, melatonin may be useful as a coadjuvant in the treatment of certain conditions of the oral cavity. However, the most important effect of melatonin seems to result from its potent antioxidant, immunomodulatory, protective, and anticancer properties. Thus, melatonin could be used therapeutically for instance, locally, in the oral cavity damage of mechanical, bacterial, fungal, or viral origin, in postsurgical wounds caused by tooth extractions and other oral surgeries. Additionally, it can help bone formation in various autoimmunological disorders such as Sjorgen syndrome, in periodontal diseases, in toxic effects of dental materials, in dental implants, and in oral cancers.

  3. Personality and oral health

    Science.gov (United States)

    Thomson, W. Murray; Caspi, Avshalom; Poulton, Richie; Moffitt, Terrie E.; Broadbent, Jonathan M.

    2013-01-01

    We investigated age-26 personality characteristics and age-32 oral health in a prospective study of a complete birth cohort born in Dunedin, New Zealand. Personality was measured using the Multidimensional Personality Questionnaire (MPQ). Oral health was measured using the short-form Oral Health Impact Profile (OHIP-14), a global measure, and dental examinations. Personality profiles were constructed for 916 individuals (50.8% men) using standardized MPQ scores, and multivariate analyses examined their association with oral health. Those reporting 1+ OHIP-14 impacts had higher Negative Emotionality scores (and lower Constraint and Positive Emotionality MPQ superfactor scores) than those who did not. After controlling for gender, clinical status, and the other two MPQ superfactors, those scoring higher on Negative Emotionality had a greater risk of reporting 1+ OHIP-14 impacts, as well as 3+ OHIP-14 impacts and worse-than-average oral health. They also had a greater risk of having lost at least one tooth from caries and of having 3+ decayed surfaces. Personality characteristics appear to shape self-reports of oral health. Personality is also a risk factor for clinical disease status, at least with respect to dental caries and its sequelae. Because the attitudes and values tapped into by personality tests can be altered by brief cognitive interventions, those might be useful in preventive dentistry. PMID:21896053

  4. Distinct and cooperative activities of HESO1 and URT1 nucleotidyl transferases in microRNA turnover in Arabidopsis.

    Directory of Open Access Journals (Sweden)

    Bin Tu

    2015-04-01

    Full Text Available 3' uridylation is increasingly recognized as a conserved RNA modification process associated with RNA turnover in eukaryotes. 2'-O-methylation on the 3' terminal ribose protects micro(miRNAs from 3' truncation and 3' uridylation in Arabidopsis. Previously, we identified HESO1 as the nucleotidyl transferase that uridylates most unmethylated miRNAs in vivo, but substantial 3' tailing of miRNAs still remains in heso1 loss-of-function mutants. In this study, we found that among nine other potential nucleotidyl transferases, UTP:RNA uridylyltransferase 1 (URT1 is the single most predominant nucleotidyl transferase that tails miRNAs. URT1 and HESO1 prefer substrates with different 3' end nucleotides in vitro and act cooperatively to tail different forms of the same miRNAs in vivo. Moreover, both HESO1 and URT1 exhibit nucleotidyl transferase activity on AGO1-bound miRNAs. Although these enzymes are able to add long tails to AGO1-bound miRNAs, the tailed miRNAs remain associated with AGO1. Moreover, tailing of AGO1-bound miRNA165/6 drastically reduces the slicing activity of AGO1-miR165/6, suggesting that tailing reduces miRNA activity. However, monouridylation of miR171a by URT1 endows the miRNA the ability to trigger the biogenesis of secondary siRNAs. Therefore, 3' tailing could affect the activities of miRNAs in addition to leading to miRNA degradation.

  5. The pleuromutilin drugs tiamulin and valnemulin bind to the RNA at the peptidyl transferase centre on the ribosome

    DEFF Research Database (Denmark)

    Poulsen, S M; Karlsson, M; Johansson, L B

    2001-01-01

    The pleuromutilin antibiotic derivatives, tiamulin and valnemulin, inhibit protein synthesis by binding to the 50S ribosomal subunit of bacteria. The action and binding site of tiamulin and valnemulin was further characterized on Escherichia coli ribosomes. It was revealed that these drugs...... results that tiamulin and valnemulin interact with the rRNA in the peptidyl transferase slot on the ribosomes in which they prevent the correct positioning of the CCA-ends of tRNAs for peptide transfer....

  6. Characterization of two novel lipopolysaccharide phosphoethanolamine transferases in Pasteurella multocida and their role in resistance to cathelicidin-2.

    Science.gov (United States)

    Harper, Marina; Wright, Amy; St Michael, Frank; Li, Jianjun; Deveson Lucas, Deanna; Ford, Mark; Adler, Ben; Cox, Andrew D; Boyce, John D

    2017-09-05

    The lipopolysaccharide (LPS) produced by the Gram-negative bacterial pathogen Pasteurella multocida has phosphoethanolamine (PEtn) residues attached to lipid A, 3-deoxy-D-manno-octulosonic acid (Kdo), heptose and galactose. In this study, we show that PEtn is transferred to lipid A by the P. multocida EptA homologue, PetL, and is transferred to galactose by a novel PEtn transferase that is unique to P. multocida called PetG. Transcriptomic analyses indicated that petL expression was positively regulated by the global regulator Fis and negatively regulated by an Hfq-dependent small RNA. Importantly, we have identified a novel PEtn transferase called PetK that is responsible for PEtn addition to the single Kdo molecule (Kdo1), directly linked to lipid A in the P. multocida glycoform A LPS. In vitro assays showed that a functional petL and petK, and therefore the presence of PEtn on lipid A and Kdo1, were essential for resistance to the cationic, antimicrobial peptide cathelicidin-2. The importance of PEtn on Kdo1 and the identification of the transferase responsible for this addition has not previously been shown. Phylogenetic analysis revealed that PetK is the first representative of a new family of predicted PEtn transferases. The PetK family consists of uncharacterized proteins from a range of Gram-negative bacteria that produce LPS glycoforms with only one Kdo molecule, including pathogenic species within the genera Vibrio, Bordetella and Haemophilus We predict that many of these bacteria will require the addition of PEtn to Kdo for maximum protection against host antimicrobial peptides. Copyright © 2017 American Society for Microbiology.

  7. Glutathione S-transferase Ya subunit gene: identification of regulatory elements required for basal level and inducible expression.

    OpenAIRE

    Telakowski-Hopkins, C A; King, R. G.; Pickett, C B

    1988-01-01

    The function of the 5'-flanking region of a rat glutathione S-transferase Ya subunit structural gene has been examined in homologous and heterologous cells. By using the 5'-flanking region of the Ya subunit gene fused to the structural gene encoding chloramphenicol acetyltransferase, we have identified two cis-acting regulatory elements in the upstream region of the Ya gene. One element is required for maximum basal level expression in homologous cells, whereas maximum basal level expression ...

  8. A fluorescent assay amenable to measuring production of beta-D-glucuronides produced from recombinant UDP-glycosyl transferase enzymes.

    Science.gov (United States)

    Trubetskoy, O V; Shaw, P M

    1999-05-01

    Beta-glucuronidase cleavage of 4-methylumbelliferyl beta-D-glucuronide generates the highly fluorescent compound, 4-methylumbelliferone. We show that other beta-D-glucuronide compounds act as competitors in this assay. The 4-methylumbelliferyl beta-D-glucuronide cleavage assay can easily be adapted to high throughput formats to detect the presence of beta-D glucuronides generated using recombinant glycosyl transferase preparations.

  9. HPV-associated oral warts.

    Science.gov (United States)

    Feller, L; Khammissa, R A G; Wood, N H; Marnewick, J C; Meyerov, R; Lemmer, J

    2011-03-01

    Human papillomavirus (HPV) is strictly epitheliotropic, infecting stratified squamous cutaneous and mucosal epithelial cells. Oral HPV infection may be subclinical or putatively associated with benign or malignant oral neoplasms. The benign HPV-associated oral lesions, focal epithelial hyperplasia (Heck disease), oral squamous cell papilloma, oral verruca vulgaris (common wart) and oral condyloma acuminatum, are collectively referred to as oral warts. Oral warts are usually asymptomatic, may be persistent or uncommonly, may regress spontaneously. HPV-associated oral warts have a prevalence of 0.5% in the general population, occur in up to 5% of HIV-seropositive subjects, and in up to 23% of HIV-seropositive subjects on highly active antiretroviral therapy. This paper is a clinico-pathological review of HPV-associated oral warts.

  10. Strengthening of oral health systems

    DEFF Research Database (Denmark)

    Petersen, Poul Erik

    2014-01-01

    Around the globe many people are suffering from oral pain and other problems of the mouth or teeth. This public health problem is growing rapidly in developing countries where oral health services are limited. Significant proportions of people are underserved; insufficient oral health care...... is either due to low availability and accessibility of oral health care or because oral health care is costly. In all countries, the poor and disadvantaged population groups are heavily affected by a high burden of oral disease compared to well-off people. Promotion of oral health and prevention of oral...... diseases must be provided through financially fair primary health care and public health intervention. Integrated approaches are the most cost-effective and realistic way to close the gap in oral health between rich and poor. The World Health Organization (WHO) Oral Health Programme will work...

  11. An alternate pathway of arsenate resistance in E. coli mediated by the glutathione S-transferase GstB.

    Science.gov (United States)

    Chrysostomou, Constantine; Quandt, Erik M; Marshall, Nicholas M; Stone, Everett; Georgiou, George

    2015-03-20

    Microbial arsenate resistance is known to be conferred by specialized oxidoreductase enzymes termed arsenate reductases. We carried out a genetic selection on media supplemented with sodium arsenate for multicopy genes that can confer growth to E. coli mutant cells lacking the gene for arsenate reductase (E. coli ΔarsC). We found that overexpression of glutathione S-transferase B (GstB) complemented the ΔarsC allele and conferred growth on media containing up to 5 mM sodium arsenate. Interestingly, unlike wild type E. coli arsenate reductase, arsenate resistance via GstB was not dependent on reducing equivalents provided by glutaredoxins or a catalytic cysteine residue. Instead, two arginine residues, which presumably coordinate the arsenate substrate within the electrophilic binding site of GstB, were found to be critical for transferase activity. We provide biochemical evidence that GstB acts to directly reduce arsenate to arsenite with reduced glutathione (GSH) as the electron donor. Our results reveal a pathway for the detoxification of arsenate in bacteria that hinges on a previously undescribed function of a bacterial glutathione S-transferase.

  12. Partial purification and characterization of a mannosyl transferase involved in O -linked mannosylation of glycoproteins in Candida albicans.

    Science.gov (United States)

    Arroyo-Flores, Blanca L; Calvo-Méndez, Carlos; Flores-Carreón, Arturo; López-Romero, Everardo

    2004-04-01

    Incubation of a mixed membrane fraction of C. albicans with the nonionic detergents Nonidet P-40 or Lubrol solubilized a fraction that catalyzed the transfer of mannose either from endogenously generated or exogenously added dolichol-P-[14C]Man onto endogenous protein acceptors. The protein mannosyl transferase solubilized with Nonidet P-40 was partially purified by a single step of preparative nondenaturing electrophoresis and some of its properties were investigated. Although transfer activity occurred in the absence of exogenous mannose acceptors and thus depended on acceptor proteins isolated along with the enzyme, addition of the protein fraction obtained after chemical de-mannosylation of glycoproteins synthesized in vitro stimulated mannoprotein labeling in a concentration-dependent manner. Other de-mannosylated glycoproteins, such as yeast invertase or glycoproteins extracted from C. albicans, failed to increase the amount of labeled mannoproteins. Mannosyl transfer activity was not influenced by common metal ions such as Mg(2+), Mn(2+) and Ca(2+), but it was stimulated up to 3-fold by EDTA. Common phosphoglycerides such as phosphatidylglycerol and, to a lower extent, phosphatidylinositol and phosphatidylcholine enhanced transfer activity. Interestingly, coupled transfer activity between dolichol phosphate mannose synthase, i.e., the enzyme responsible for Dol-P-Man synthesis, and protein mannosyl transferase could be reconstituted in vitro from the partially purified transferases, indicating that this process can occur in the absence of cell membranes.

  13. Phosphorylation of the Lipid A Region of Meningococcal Lipopolysaccharide: Identification of a Family of Transferases That Add Phosphoethanolamine to Lipopolysaccharide

    Science.gov (United States)

    Cox, Andrew D.; Wright, J. Claire; Li, Jianjun; Hood, Derek W.; Moxon, E. Richard; Richards, James C.

    2003-01-01

    A gene, NMB1638, with homology to the recently characterized gene encoding a phosphoethanolamine transferase, lpt-3, has been identified from the Neisseria meningitidis genome sequence and was found to be present in all meningococcal strains examined. Homology comparison with other database sequences would suggest that NMB1638 and lpt-3 represent genes coding for members of a family of proteins of related function identified in a wide range of gram-negative species of bacteria. When grown and isolated under appropriate conditions, N. meningitidis elaborated lipopolysaccharide (LPS) containing a lipid A that was characteristically phosphorylated with multiple phosphate and phosphoethanolamine residues. In all meningococcal strains examined, each lipid A species contained the basal diphosphorylated species, wherein a phosphate group is attached to each glucosamine residue. Also elaborated within the population of LPS molecules are a variety of “phosphoforms” that contain either an additional phosphate residue, an additional phosphoethanolamine residue, additional phosphate and phosphoethanolamine residues, or an additional phosphate and two phosphoethanolamine residues in the lipid A. Mass spectroscopic analyses of LPS from three strains in which NMB1638 had been inactivated by a specific mutation indicated that there were no phosphoethanolamine residues included in the lipid A region of the LPS and that there was no further phosphorylation of lipid A beyond one additional phosphate species. We propose that NMB1638 encodes a phosphoethanolamine transferase specific for lipid A and propose naming the gene “lptA,” for “LPS phosphoethenolamine transferase for lipid A.” PMID:12754224

  14. Effect of trans-acting factor on rat glutathione S-transferase P1 gene transcription regulation in tumor cells

    Institute of Scientific and Technical Information of China (English)

    刘东远; 廖名湘; 左瑾; 方福德

    2002-01-01

    Objective To investigate the effect of trans-acting factor(s) on rat glutathione S-transferase P1 gene (rGSTP1) transcription regulation in tumor cells. Methods The binding of trans-acting factor(s) to two enhancers of the rGSTP1 gene, glutathione S-transferase P enhancer Ⅰ (GPEI) and glutathione S-transferase P enhancer Ⅱ-1 (GPEⅡ-1), was identified by an electrophoretic mobility shift assay (EMSA). The molecular weight of trans-acting factor was measured in a UV cross-linking experiment. Results Trans-acting factor interacting with the core sequence of GPEI (cGPEI) were found in human cervical adenocarcinoma cell line (HeLa) and rat hepatoma cell line (CBRH7919). These proteins were not expressed in normal rat liver. Although specific binding proteins that bound to GPEⅡ-1 were detected in all three cell types, a 64 kDa binding protein that exists in HeLa and CBRH7919 cells was absent in normal rat liver. Conclusion cGPEI, GPEII specific binding proteins expressed in HeLa and CBRH7919 cells may play an important role in the high transcriptional level of the rGSTP1 gene in tumor cells.

  15. Neuroantibodies (NAB) in African-American Children: Associations with Gender, Glutathione-S-Transferase (GST)Pi Polymorphisms (SNP) and Heavy Metals

    Science.gov (United States)

    CONTACT (NAME ONLY): Hassan El-Fawal Abstract Details PRESENTATION TYPE: Platform or Poster CURRENT CATEGORY: Neurodegenerative Disease | Biomarkers | Neurotoxicity, Metals KEYWORDS: Autoantibodies, Glutathione-S-Transferase, DATE/TIME LAST MODIFIED: DATE/TIME SUBMITTED: Abs...

  16. ORAL MYIASIS CONVERTING TO ORAL SQUAMOUS CELL CARCINOMA

    Directory of Open Access Journals (Sweden)

    Akshay

    2015-10-01

    Full Text Available INTRODUCTION: Oral Myiasis, a condition of infestation of the body by fly larvae (maggots is a rare pathology in humans. It is associated with poor oral hygiene, alcoholism, senility, suppurating lesions, severe halitosis. It is seen frequently in tropical countries and hot climatic regions. The reported cases in literature of oral Myiasis associated with oral cancer are few. The treatment is a mechanical removal of the maggots but a systemic treatment with Ivermectin, a semi - synthetic macrolide antibiotic, has been used successfully for treatment for oral m yiasis. We present a case of 55 yr old male alcoholic patient with oral myiasis with extensive proliferative growth of oral cavity. Our patient was managed with manual debridement and administration of systemic ivermect in along with antibiotic coverage. Incisional biopsy of the proliferative lesion showed well differentiated squamous cell carcinoma. Thus our patient showed presence of oral myiasis in association with oral squamous cell carcinoma.

  17. Antioxidant farnesylated hydroquinones from Ganoderma capense.

    Science.gov (United States)

    Peng, Xingrong; Li, Lei; Wang, Xia; Zhu, Guolei; Li, Zhongrong; Qiu, Minghua

    2016-06-01

    Phytochemical investigation of the fruiting bodies of Ganoderma capense led to isolation of eight aromatic meroterpenoids (1-8). Ganocapensins A and B (1, 2) possessed a thirteen-membered and a fourteen-membered ether rings, respectively. The structures of new isolates including absolute configuration were elucidated on the basis of extensive spectroscopic technologies and Mosher's method. All isolated compounds showed significant antioxidant effects with IC50 values ranging from 6.00±0.11 to 8.20±0.30μg/ml in the DPPH radical scavenging assay.

  18. Paracoccidioidomicosis en cavidad oral Oral cavity paracoccidioidomycosis

    OpenAIRE

    D. Antunes Freitas; C.I. Vergara Hernández; A. Díaz Caballero; G. Moreira

    2012-01-01

    La paracoccidioidomicosis (PCM) o blastomicosis suramericana es la micosis sistémica más importante de América latina que es relativamente común en Brasil, Venezuela, Colombia, Ecuador y Argentina. Los casos esporádicos también pueden verse en algunos otros países, la cual es progresiva y con un infrecuente desenlace fatal si no es tratada a tiempo. Se considera como una enfermedad multifocal, con lesiones orales como la característica prominente. Es causada por un hongo dimórfico, Paracoccid...

  19. Glutathione S-transferase P protects against cyclophosphamide-induced cardiotoxicity in mice

    Energy Technology Data Exchange (ETDEWEB)

    Conklin, Daniel J., E-mail: dj.conklin@louisville.edu [Diabetes and Obesity Center, University of Louisville, Louisville, KY 40292 (United States); Institute of Molecular Cardiology, University of Louisville, Louisville, KY 40292 (United States); Haberzettl, Petra; Jagatheesan, Ganapathy; Baba, Shahid [Diabetes and Obesity Center, University of Louisville, Louisville, KY 40292 (United States); Institute of Molecular Cardiology, University of Louisville, Louisville, KY 40292 (United States); Merchant, Michael L. [Diabetes and Obesity Center, University of Louisville, Louisville, KY 40292 (United States); Division of Nephrology, Department of Medicine, University of Louisville, Louisville, KY 40292 (United States); Prough, Russell A. [Diabetes and Obesity Center, University of Louisville, Louisville, KY 40292 (United States); Department of Biochemistry and Molecular Biology, University of Louisville, Louisville, KY 40292 (United States); Williams, Jessica D. [University of Cincinnati College of Medicine, Internal Medicine, Cincinnati, OH 45267 (United States); Prabhu, Sumanth D. [Division of Cardiovascular Disease, University of Alabama-Birmingham, Birmingham, AL 35294 (United States); Bhatnagar, Aruni [Diabetes and Obesity Center, University of Louisville, Louisville, KY 40292 (United States); Institute of Molecular Cardiology, University of Louisville, Louisville, KY 40292 (United States); Department of Biochemistry and Molecular Biology, University of Louisville, Louisville, KY 40292 (United States)

    2015-06-01

    High-dose chemotherapy regimens using cyclophosphamide (CY) are frequently associated with cardiotoxicity that could lead to myocyte damage and congestive heart failure. However, the mechanisms regulating the cardiotoxic effects of CY remain unclear. Because CY is converted to an unsaturated aldehyde acrolein, a toxic, reactive CY metabolite that induces extensive protein modification and myocardial injury, we examined the role of glutathione S-transferase P (GSTP), an acrolein-metabolizing enzyme, in CY cardiotoxicity in wild-type (WT) and GSTP-null mice. Treatment with CY (100–300 mg/kg) increased plasma levels of creatine kinase-MB isoform (CK·MB) and heart-to-body weight ratio to a significantly greater extent in GSTP-null than WT mice. In addition to modest yet significant echocardiographic changes following acute CY-treatment, GSTP insufficiency was associated with greater phosphorylation of c-Jun and p38 as well as greater accumulation of albumin and protein–acrolein adducts in the heart. Mass spectrometric analysis revealed likely prominent modification of albumin, kallikrein-1-related peptidase, myoglobin and transgelin-2 by acrolein in the hearts of CY-treated mice. Treatment with acrolein (low dose, 1–5 mg/kg) also led to increased heart-to-body weight ratio and myocardial contractility changes. Acrolein induced similar hypotension in GSTP-null and WT mice. GSTP-null mice also were more susceptible than WT mice to mortality associated with high-dose acrolein (10–20 mg/kg). Collectively, these results suggest that CY cardiotoxicity is regulated, in part, by GSTP, which prevents CY toxicity by detoxifying acrolein. Thus, humans with low cardiac GSTP levels or polymorphic forms of GSTP with low acrolein-metabolizing capacity may be more sensitive to CY toxicity. - Graphical abstract: Cyclophosphamide (CY) treatment results in P450-mediated metabolic formation of phosphoramide mustard and acrolein (3-propenal). Acrolein is either metabolized and

  20. Association of catechol-o-methyl transferase gene polymorphism with prostate cancer and benign prostatic hyperplasia

    Directory of Open Access Journals (Sweden)

    mir davood omrani

    2009-08-01

    Full Text Available

    • BACKGROUND: A single nucleotide variation within  atechol-o-methyl transferase (COMT gene may alter the COMT enzyme activity level. Polymorphism of Val158Met in the COMT gene has been related to malignancy. In this regard, a study was carried out to find a possible association between the COMT gene polymorphism in patients with sporadic prostate cancer (PCa and benign prostatic hyperplasia (BPH.
    • METHODS: All types of COMT158 Val/Met polymorphism were carried out using ASO-PCR method in 41 patients with prostate cancer, 193 patients with benign prostatic hyperplasia and 107 healthy male individuals.
    • RESULTS: The results of this study showed that the frequency of low producer allele A at codon 158 of the  OMT gene is significantly different in BPH group compared to normal male control group (OR, 95% CI, p value 1.95: 1.46, 2.44, 0.021, respectively. However no significant difference was noticed when the comparison was made between prostate cancer group and normal male control group and also between BPH and PCa groups.
    • CONCLUSIONS: Decreased level of catechol-o-methyl transferase gene