Ribulose-1,5-bisphosphate Carboxylase-Oxygenase: New Aspects Respective the pH-Dependance of the Carboxylation Reaction

1983 ◽  
Vol 38 (3-4) ◽  
pp. 243-246 ◽  
Author(s):  
P. Braun ◽  
J. Bode ◽  
A. Wild
Keyword(s):  
Crude Enzyme ◽  
Activity Profile ◽  
Reaction Conditions ◽  
Carboxylase Activity ◽  
Bisphosphate Carboxylase ◽  
Ribulose 1 ◽  
Substrate Concentrations

The investigation was directed towards the effects of reaction conditions, substrates and pH on the carboxylation reaction of ribulose-1 ,5-bisphosphate carboxylase-oxygenase in the crude enzyme extracts from several plants. Optimal substrate concentrations (HCO3- and RubP) were determined. The highest carboxylase activity was attained with Tris/HCl buffer. The pH activity profile was quite sharp with an optimum at pH 7.8. Purified and crystallized carboxylase yielded a broad optimum curve under the same reaction conditions

Ribulose-1, 5-bisphosphate carboxylase activity, chlorophyll and protein concentrations in differentPopulus clones

1982 ◽  
Vol 24 (1) ◽  
pp. 57-62 ◽  
Author(s):  
R. Ceulemans ◽  
F. Van Assche ◽  
I. Impens ◽  
H. Clusters
Keyword(s):  
Carboxylase Activity ◽  
Bisphosphate Carboxylase ◽  
Ribulose 1

Three-dimensional distribution of ribulose-1, 5-bisphosphate carboxylase/oxygemase during the early development of proplastids in dark-grown Euglena cells transferred to an inorganic medium

1990 ◽  
Vol 48 (3) ◽  
pp. 906-907
Author(s):  
Tomoko Ehara ◽  
Shuji Sumida ◽  
Tetsuaki Osafune ◽  
Eiji Hase
Keyword(s):  
Cell Suspension ◽  
Euglena Gracilis ◽  
Carbon Materials ◽  
Three Dimensional ◽  
Peripheral Region ◽  
Plastid Development ◽  
Bisphosphate Carboxylase ◽  
Inorganic Medium ◽  
Ribulose 1 ◽  
Dimensional Distribution

As shown previously, Euglena cells grown in Hutner’s medium in the dark without agitation accumulate wax as well as paramylum, and contain proplastids showing no internal structure except for a single prothylakoid existing close to the envelope. When the cells are transferred to an inorganic medium containing ammonium salt and the cell suspension is aerated in the dark, the wax was oxidatively metabolized, providing carbon materials and energy 23 for some dark processes of plastid development. Under these conditions, pyrenoid-like structures (called “pro-pyrenoids”) are formed at the sites adjacent to the prolamel larbodies (PLB) localized in the peripheral region of the proplastid. The single prothylakoid becomes paired with a newly formed prothylakoid, and a part of the paired prothylakoids is extended, with foldings, in to the “propyrenoid”. In this study, we observed a concentration of RuBisCO in the “propyrenoid” of Euglena gracilis strain Z using immunoelectron microscopy.

Role of salicylic acid in regulation of cadmium toxicity in wheat ( Triticum aestivum L.)

2009 ◽  
Vol 57 (3) ◽  
pp. 321-333 ◽  
Author(s):  
H. Moussa ◽  
S. EL-Gamal
Keyword(s):  
Pyruvate Carboxylase ◽  
Cadmium Toxicity ◽  
Triticum Aestivum L ◽  
Carboxylase Activity ◽  
Bisphosphate Carboxylase ◽  
Cd Accumulation ◽  
Phosphoenol Pyruvate ◽  
Relative Water ◽  
Aba Content

Treatment with CdCl 2 (0, 100, 400 and 1000 μM) resulted in the inhibition of root dry biomass and root elongation and to increased Cd accumulation in the roots. These treatments also decreased the relative water content, chlorophyll content, 14 CO fixation, phosphoenol pyruvate carboxylase and ribulose-1,5-bisphosphate carboxylase activity and abscisic acid (ABA) content, while increasing the malondialdehyde, hydrogen peroxide and free proline contents and causing changes in the chloroplast and root ultrastructure. Pretreatment of seeds with SA (500 μM) for 20 h resulted in the amelioration of these effects.

scholarly journals Ribulose 1,5-bisphosphate carboxylase. Effect on the catalytic properties of changing methionine-330 to leucine in the Rhodospirillum rubrum enzyme

1986 ◽  
Vol 235 (3) ◽  
pp. 839-846 ◽  
Author(s):  
B E Terzaghi ◽  
W A Laing ◽  
J T Christeller ◽  
G B Petersen ◽  
D F Hill
Keyword(s):  
Rhodospirillum Rubrum ◽  
Oligonucleotide Primer ◽  
Similar Amount ◽  
Ribulose Bisphosphate Carboxylase ◽  
Ribulose Bisphosphate ◽  
Carboxylase Activity ◽  
Bisphosphate Carboxylase ◽  
Ribulose Bisphosphate Carboxylase Oxygenase ◽  
In The Wild ◽  
The Stability

Oligonucleotide-directed mutagenesis of cloned Rhodospirillum rubrum ribulose bisphosphate carboxylase/oxygenase with a synthetic 13mer oligonucleotide primer was used to effect a change at Met-330 to Leu-330. The resultant enzyme was kinetically examined in some detail and the following changes were found. The Km(CO2) increased from 0.16 to 2.35 mM, the Km(ribulose bisphosphate) increased from 0.05 to 1.40 mM for the carboxylase reaction and by a similar amount for the oxygenase reaction. The Ki(O2) increased from 0.17 to 6.00 mM, but the ratio of carboxylase activity to oxygenase activity was scarcely affected by the change in amino acid. The binding of the transition state analogue 2-carboxyribitol 1,5-bisphosphate was reversible in the mutant and essentially irreversible in the wild type enzyme. Inhibition by fructose bisphosphate, competitive with ribulose bisphosphate, was slightly increased in the mutant enzyme. These data suggest that the change of the residue from methionine to leucine decreases the stability of the enediol reaction intermediate.

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