EurekaMag.com logo
+ Site Statistics
References:
48,253,228
Abstracts:
22,798,842
+ Resolve Accession
+ Subscribe to Site Feeds
EurekaMag Most Shared ContentMost Shared
EurekaMag PDF Full Text ContentPDF Full Text
+ PDF Full Text
Request PDF Full TextRequest PDF Full Text
Submit PDF Full TextSubmit PDF Full Text
+ Follow Us
Follow on FacebookFollow on Facebook
Follow on TwitterFollow on Twitter
Follow on Google+Follow on Google+
Follow on LinkedInFollow on LinkedIn

+ Translate

Different Characteristics of the Two Glutamate Synthases in the Green Leaves of Lycopersicon esculentum


, : Different Characteristics of the Two Glutamate Synthases in the Green Leaves of Lycopersicon esculentum. Plant Physiology 85(4): 1036-1039

The two glutamate synthases, NAD(P)H- and ferredoxin-dependent, from the green leaves of tomato plants (Lycopersicon esculentum L. cv Hellfrucht frühstamm) differed in their chemical properties and catalytic behavior. Gel filtration of NAD(P)H enzyme gave an apparent molecular size of 158 kilodalton, whereas the ferredoxin enzyme molecular size was 141 kilodalton. Arrhenius plots of the activities of the two enzymes showed that the NAD(P)H enzyme had two activation energies; 109.6 and 70.5 kilojoule per mole; the transition temperature was 22 degrees C. The ferredoxin enzyme however, had only one activation energy; 56.1 kilojoule per mole. The respective catalytic activity pH optima for the NAD(P)H- dependent and the ferredoxin dependent enzymes were around 7.3 and 7.8. In experiments to evaluate the effects of modulators aspartate enhanced the NAD(P)H-linked activity, with a K(a) value of 0.25 millimolar, but strongly inhibited that of the ferredoxin-dependent glutamate synthase with a K(i) of 0.1 millimolar. 3-Phosphoserine was another inhibitor of the ferredoxin dependent enzyme with a K(i) value of 4.9 millimolar. 3-Phosphoglyceric acid was a potent inhibitor of the ferredoxin-dependent form, but hardly affected the NAD(P)H-dependent enzyme. The results are discussed and interpreted to propose different specific functions that these activities may have within the leaf tissue cell.

(PDF same-day service: $19.90)

Order PDF Full Text

Close
Close

Click here to order any other PDF Full Text


Accession: 005151982

PMID: 16665799

DOI: 10.1104/pp.85.4.1036

PDF Full Text: Submit


Submit PDF Full Text

No spam - Every submission is manually reviewed

Due to poor quality, we do not accept files from Researchgate

Submitted PDF Full Texts will always be free for everyone
(We only charge for PDFs that we need to acquire)

Select a PDF file:
Close
Close

Other references

Mukaddam Daher, Suhayla; El Ayoubi, Rody; Menaouar, Ahmed; Gutkowska, Jolanta, 2002: Involvement of atrial natriuretic peptide and nitric oxide systems in the cardioprotective effects of chronic moxonidine treatment in spontaneously hypertensive rats. The antihypertensive action of the imidazoline compound, moxonidine, is mediated by selective activation of imidazoline receptors and subsequent sympathoinhibition. In addition, moxonidine-stimulated atrial natriuretic peptides (ANP) and/or increa...

Anonymous, 1976: Grow high yielding rice varieties. Indian farm mechanization: 17 (5) 8-9

Rademacher, W., 2004: Future role of plant bioregulators in fruit production. This paper focuses on the role of plant bioregulators (PBRs) in modern agriculture and horticulture, particularly in fruit production. The reasons for decreasing interest in PBRs are identified and an outlook for future developments is provided.

Hussein, Mamoun M.; Migton, John, 2001: Effervescent histamine H2 antagonist composition. A histamine H2 antagonist incompatible with acidic materials is incorporated in an effervescent composition and is stable therein provided the acidulant employed in the effervescent couple is a non-hydroxy group containing acidulant and such acidu...

Kralova M.; Masscheleyn P.H.; Lindau C.W.; Patrick W.H.Jr, 1992: Production of dinitrogen and nitrous oxide in soil suspensions as affected by redox potential. The effect of soil redox potential on N2O and N3 emission from soil suspensions was studied under laboratory conclusions. Crowley silt loam soil suspensions were equilibrated under controlled (-200, -100, 0, +100, +200, +300, and +400 mV) redox le...

Nott, S. B.; Kauffman, D. E.; Speicher, J. A., 1981: Trends in the management of dairy farms since 1956. In the last 25 yr the number of dairy cows in the USA has fallen from >20 million to <11 million; the number of small farms has fallen substantially but av. farm size has increased. This review emphasizes the diversity within US dairy farmin...

Komizu, Y.; Tomonaga, Y.; Goto, K.; Ueoka, R., 2006: Remarkable immunostimulation effects of hybrid liposomes on human peripheral blood mononuclear cells in vitro. Immunostimulation effects of hybrid liposomes (HL25) composed Of 90 mol% L-alpha-dimyristoylphosphatidylcholine (DMPC) and 10 mol% polyoxyethylene(25)dodecyl ether (C-12(EO)(25)) on the normal human peripheral blood mononuclear cells (hPBMCs) wer...

Holtzworth-Munroe, A.; Hutchinson, G., 1993: Attributing negative intent to wife behavior: the attributions of maritally violent versus nonviolent men. This study compared attributions for negative wife behavior offered by three groups of husbands: 22 maritally violent and distressed, 17 nonviolent but maritally distressed, and 17 nonviolent and nondistressed. Husbands rated wife behaviors presen...

Park A.W., 1974: Biology of the rice rat oryzomys palustris natator in a laboratory environment part 4 mineralization of the molar teeth. Acta Anatomica 87(3): 433-446

Mockel, Reinhard.; Gunther, Dietmar., 1991: Die Reproduktionsrate des Sperbers Accipiter nisus im Westerzgebirge in den Jahren 1974-1989. Martin-Luther-Universitaet Halle-Wittenberg Wissenschaftliche Beitraege, 4: 317-332 P 45