H. M. El-Shora
Botany Department, Faculty of Science, Mansoura University, Mansoura, Egypt
ABSTRACT
NADH-Glutamate synthase (GOGAT, E.C. 1.4.1.14) from Cucurbita pepo L. (marrow) cotyledons was inhibited by abscisic acid (ABA) at 10-6 M. Addition of either gibberellic acid (GA3) or dichlorophenoxyacetic acid (2,4-D) at 10-6 M to ABA counteracted its inhibitory effect. Kinetin at the same concentration increased inhibition of the enzyme by ABA. Cycloheximide, rifampicin, cordycepin and chloramphenicol at 0.3 M reduced mediated-increase in the enzyme activity by 2,4-D particularly in vivo. The enzyme was purified to homogeneity as determined by sodium dodecyl sulfate-polyacrylamide gels. The subunit Mr of GOGAT as determined by SDS-PAGE was 200 KDa. The specific activity was 131.2 U mg-1 protein. Group-specific modifiers like N-bromosuccinimide (NBS), Densyl chloride (DC), Tetranitromethane (TNM) and 2-ethoxy-1-ethoxy-1,2-dihydroquinoline (EEDQ) inactivated the purified enzyme. The results suggested the presence of tryptophanyl, lysyl, tyrosyl and carboxyl groups essential for the enzyme catalysis. Double logarithmic plots of the observed pseudo-first order rate constants against modifier concentration revealed modification of only one residue of each group.
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How to cite this article
H. M. El-Shora, 2001. Effect of Growth Regulators and Group-Modifiers on NADH-Glutamate
Synthase of Marrow Cotyledons. Journal of Biological Sciences, 1: 597-602.
DOI: 10.3923/jbs.2001.597.602
URL: https://scialert.net/abstract/?doi=jbs.2001.597.602
DOI: 10.3923/jbs.2001.597.602
URL: https://scialert.net/abstract/?doi=jbs.2001.597.602
REFERENCES
- Bihzad, M.A. and H.M. El-Shora, 1996. Phosphoenolpyruvate carboxylase from Rumex dentatus, a C3-plant. J. Plant Physiol., 149: 669-676.
CrossRefDirect Link - Chen, P.K., M. Polatnick and G. Leather, 1991. Comparative study on artemisinin, 2,4-D and glyphosate. J. Agric. Food Chem., 39: 991-994.
CrossRefDirect Link - Kumar, V., A.S. Basra and C.B. Malik, 1987. Enzymes of non-photosynthetic C4 dicarboxylic acid metabolism in germinating seeds of wheat. Biochemie und Physiologie der Pflanzen, 182: 261-265.
CrossRefDirect Link - Laemmli, U.K., 1970. Cleavage of structural proteins during the assembly of the head of bacteriophage T4. Nature, 227: 680-685.
CrossRefDirect Link - Lam, H.M., K.T. Coschigano, I.C. Oliveira, R. Melo-Oliveira and G.M. Coruzzi, 1996. The molecular-genetics of nitrogen assimilation into amino acids in higher plants. Ann. Rev. Plant Physiol. Plant Mol. Biol., 47: 569-593.
CrossRefPubMedDirect Link - Guifoyla, T.J., C.Y. Li, T. Chen, R.T. Nago and J.L. Key, 1975. Enhancement of soybean RNA polymerase I by auxin. Proc. Natl. Acad. USA., 72: 69-72.
Direct Link - Becker, T.W., C. Perrot-Rechenmann, A. Suzuki and B. Hirel, 1993. Subcellular and immunocytochemical localization of the enzymes involved in ammonia assimilation in mesophyll and bundle-sheath cells of maize leaves. Planta, 191: 129-136.
CrossRefDirect Link - Van Der Zaal, B.J., F.N. Droog, F.J. Pieterse and P.J. Hooykaas, 1996. Auxin-sensitive elements from promoters of tobacco GST genes and a consensus as-1-like element differ only in relative strength. Plant Physiol., 110: 79-88.
PubMedDirect Link - Brightman, A.O., R. Barr, F.L. Crane and D.J. Morre, 1988. Auxin-stimulated NADH oxidase purified from plasma membrane of soybean. Plant Physiol., 86: 1264-1269.
CrossRefDirect Link - Chen, F.L. and J.V. Cullimore, 1989. Location of two isoenzymes of NADH-dependent glutamate synthase in root nodules of Phaseolus vulgaris L. Planta, 179: 441-447.
CrossRefDirect Link - Dougall, D.K., 1974. Evidence for the presence of glutamate synthase in extracts of carrot cells cultures. Biochem. Biophys. Res. Commun., 58: 639-646.
CrossRefDirect Link - Emes, M.J. and S. England, 1986. Purification of plastids from higher-plant roots. Planta, 168: 161-166.
CrossRefDirect Link - Grierson, D., R.J. Kear, J.R. Thompson and M.R. Garica, 1982. Stimulation of in vitro RNA synthesis by pretreating plants with auxins is due to auxin-induced ethylene production. Zeitschrift fur Pflanzenphysiologie, 107: 419-426.
CrossRefDirect Link - Hecht, U., R. Oelmuller, S. Schmidt and H. Mohr, 1988. Action of light, nitrate and ammonium on the levels of NADH-and ferredoxin-dependent glutamate synthases in the cotyledons of mustard seedlings. Planta, 175: 130-138.
CrossRefDirect Link - Hirose, N. and I. Yamaya, 1999. Okadaic acid mimics nitrogen-stimulated transcription of the NADH-glutamate synthase gene in rice cell cultures. Plant Physiol., 211: 805-815.
Direct Link - Jacobsen, S.E. and N.E. Olszewski, 1996. Gibberellins regulate the abundance of RNAs with sequence similarity to proteinase inhibitors, dioxygenases and dehydrogenases. Planta, 198: 78-82.
CrossRefDirect Link - Jones, R.L. and D.S. Jacobsen, 1991. Regulation of synthesis and transport of secreted proteins in cereal aleurone. Int. Rev. Cytol., 126: 49-88.
CrossRefDirect Link - Kendall, A.C., R.M. Wallsgrove, N.P. Hall, J.C. Turner and P.J. Lea, 1986. Carbon and nitrogen metabolism in barley (Hordeum vulgare L.) mutants lacking ferredoxin-dependent glutamate synthase. Planta, 168: 316-323.
CrossRefDirect Link - Lowry, O.H., N.J. Rosebrough, A.L. Farr and R.J. Randall, 1951. Protein measurement with the folin phenol reagent. J. Biol. Chem., 193: 265-275.
CrossRefPubMedDirect Link - Matoh, T. and E. Takahashi, 1981. Glutamate synthase in greening pea shoots. Plant Cell Physiol., 22: 727-731.
CrossRefDirect Link - Migge, A., E. Carrayol, C. Kunz, B. Hirel, H. Fock and T. Becker, 1997. The expression of the tobacco genes encoding plastidic glutamine synthetase or ferredoxin-dependent glutamate synthase does not depend on the rate of nitrate reduction and is unaffected by suppression of photorespiration. J. Exp. Bot., 48: 1175-1184.
CrossRefDirect Link - McCarthy, R.M., P. Farmer and D. Sheehan, 1996. Binding of 2-hydroxy-5-nitrobenzyl alcohol to rat alpha class glutathione S-transferases; evidence for binding at tryptophan 21. Biochem. Biophys. Acta-Protein Struct. Mol. Enzymol., 1293: 185-190.
CrossRefDirect Link - Rudnicki, R., W. Kaminski and J. Pieniazek, 1971. The interaction of abscisic acid with growth stimulators in germination of partially after-ripened apple embryos. Biol. Planta., 13: 122-127.
CrossRefDirect Link - Ryc, M. and S. Lewak, 1982. Hormone interactions in the formation of the photosynthetic apparatus in dormant and stratified apple embryos. Zeitschrift fur Pflanzenphysiologie, 107: 15-24.
CrossRefDirect Link - Sakakibara, H., K. Kobayashi, A. Deji and T. Sugiyama, 1997. Partial characterization of the signaling pathway for the nitrate-dependent expression of genes for nitrogen-assimilatory enzymes using detached maize leaves. Plant Cell Physiol., 33: 837-843.
CrossRefDirect Link - Schreier, H.J. and T. Bernlohr, 1984. Purification and properties of glutamate synthase from Bacillus licheniformis. J. Bacteriol., 160: 591-599.
PubMedDirect Link - Srivasankar, S. and A. Oaks, 1996. Nitrate assimilation in higher plants: The effect of metabolites and light. Plant Physiol. Biochem., 34: 609-620.
Direct Link - Skoubas, A. and T. Georgatsos, 1997. Identification of essential amino acids for the catalytic activity of barley β-glucosidase. Phytochemistry, 46: 997-1003.
CrossRefDirect Link - Somerville, C.R. and W.L. Ogren, 1997. Inhibition of photosynthesis in Arabidopsis mutants lacking leaf glutamate synthase activity. Nature, 286: 257-259.
CrossRefDirect Link - Suzuki, A., W. Burkhart and S. Rothstein, 1996. Nitrogen effects on the induction of ferredoxin-dependent glutamate synthase and its mRNA in maize leaves under the light. Plant Sci., 114: 83-91.
CrossRefDirect Link - Temple, S.J., C.P. Vance and J.S. Gantt, 1998. Glutamate synthase and nitrogen assimilation. Trends Plant Sci., 3: 51-56.
CrossRefDirect Link - Vigara, A.J., M.I. Garcia-Sanchez, C. Gotor and J.M. Vega, 1996. Interaction between glutamate synthase and ferredoxin from Monoraphidium braunii. Chemical modifications and cross-linking studies. Plant Physiol. Biochem., 34: 707-711.
Direct Link - Zurfluh, L.L. and T.J. Guilfoyle, 1982. Auxin-and ethylene-induced changes in the population of translatable messenger RNA in basal sections and intact soybean hypocotyl. Plant Physiol., 69: 338-340.
Direct Link