Small Oligomers of Ribulose-bisphosphate Carboxylase/Oxygenase (Rubisco) Activase Are Required for Biological Activity
نویسندگان
چکیده
منابع مشابه
Rubisco Activase Mediates ATP-Dependent Activation of Ribulose Bisphosphate Carboxylase.
The activation level of ribulosebisphosphate carboxylase following preincubation with ribulose 1,5-bisphosphate was increased by ATP and ribulosebisphosphate carboxylase activase in the absence of thylakoids or illumination. Maximal activation was obtained with 0.5 millimolar ATP in the presence of an ATP regenerating system (phosphoenolpyruvate and pyruvate kinase). Without the ATP regeneratin...
متن کاملActivation of ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) by rubisco activase : effects of some sugar phosphates.
The activation of purified ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) has been studied in the presence of sugar phosphates, and the effect of rubisco activase on this process determined. During an 11-minute time course at pH 7.7 and 11 micromolar CO(2), the activation of rubisco was strongly inhibited by ribulose-1,5-bisphosphate (4 millimolar), fructose-1,6-bisphosphate (1 milli...
متن کاملModerately High Temperatures Inhibit Ribulose-1,5-Bisphosphate Carboxylase/Oxygenase (Rubisco) Activase-Mediated Activation of Rubisco
We tested the hypothesis that light activation of ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco) is inhibited by moderately elevated temperature through an effect on Rubisco activase. When cotton (Gossypium hirsutum L.) or wheat (Triticum aestivum L.) leaf tissue was exposed to increasing temperatures in the light, activation of Rubisco was inhibited above 35 and 30 degreesC, respect...
متن کاملDetermination of Apparent Km Values for Ribulose 1,5- Bisphosphate Carboxylase/Oxygenase (Rubisco) Activase Using the Spectrophotometric Assay of Rubisco Activity1
The spectrophotometric assay for ribulose 1,5-bisphosphate carboxylase/oxygenase (Rubisco) was used to determine the rate of increase in Rubisco activity over time in the presence or absence of Rubisco activase. Polynomial approximations to the raw data were used to smooth out minor fluctuations in the spectrophotometer readings, and Rubisco activase activity was expressed as nanomoles of activ...
متن کاملRegulation of ribulose-1,5-bisphosphate carboxylase/oxygenase (rubisco) activase: product inhibition, cooperativity, and magnesium activation.
In many photosynthetic organisms, tight-binding Rubisco inhibitors are released by the motor protein Rubisco activase (Rca). In higher plants, Rca plays a pivotal role in regulating CO2 fixation. Here, the ATPase activity of 0.005 mm tobacco Rca was monitored under steady-state conditions, and global curve fitting was utilized to extract kinetic constants. The kcat was best fit by 22.3 ± 4.9 mi...
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ژورنال
عنوان ژورنال: Journal of Biological Chemistry
سال: 2013
ISSN: 0021-9258
DOI: 10.1074/jbc.m113.466383