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1.
Properties and regulation of ribulose diphosphate carboxylase from Thiobacillus novellus 总被引:1,自引:0,他引:1
Ribulose-diphosphate carboxylase from Thiobacillus novellus has been purified to homogeneity as observed by polyacrylamide gel electrophoresis and U. V. light observation during sedimentation velocity analysis. The optimum pH for the enzyme with Tris-HCl buffers was about 8.2. Concentrations of this buffer in excess of 80 mM were inhibitory. The apparent K
m
RuDP was about 14.8 M with a Hill value of 1.5, for HCO
3
-
the apparent K
m
was about 11.7 mM with an n value of 1.18 and for Mg2+ about 0.61 mM. The enzyme was specific for this cation. Relatively high concentrations of either Hg2+ or pCMB were required before significant inhibition was observed. Activity declined slowly during a 4-hr incubation period in either 3.0 M or 8.0 M urea. Incubation for 12 hrs resulted in complete loss of activity which was not prevented by 10 mM Mg2+ and was not reversed by dialysis and subsequent addition of 10 mM cysteine. Polyacrylamide gel electrophoresis revealed a loss of the major band and the appearance of 2 new bands. SDS polyacrylamide gel electrophoresis gave an average M.W. of 73 500±2500 for the slower moving band and 12250 ±2500 for the faster moving. However, incubation in urea for up to 40 hrs revealed a decrease in the M.W. of the slower moving band to about 60000. The E
a
for the enzyme was calculated to be about 18.85 kcal mole-1, with the possibility of a break between 40 and 50°C. The Q
10 was 3.07 between 20 to 30°C whereas between 30 to 40°C it was 3.31. Only phosphorylated compounds caused significant inhibition of enzyme activity. They included ADP, FDP, F6P, G6P, PEP, 6PG, 2-PGA, R1P, R5P and Ru5P.Abbreviations ATP
adenosine-5-triphosphate
- FDP
fructose-1,6-diphosphate
- F6P
fructose-6-phosphate
- G6P
glucose-6-phosphate
- GPDH
glyceraldehyde-3-phosphate dehydrogenase
- NADH
nicotinamide adenine dinucleotide (reduced)
- OAA
oxalacetate
- pCMB
parachlormercuribenzoate
- PEP
phosphoenolpyruvate
- 6PG
6-phosphogluconate
- 2-PGA
2-phosphoglycerate
- 3-PGA
3-phosphoglycerate
- PGK
3-phosphoglyceric phosphokinase
- R1P
ribose-1-phosphate
- R5P
ribose-5-phosphate
- RuDP
ribulose-1,5-diphosphate
- Ru5P
ribulose-5-phosphate
- SDS
sodium dodecyl sulfate 相似文献
2.
Nonidentical subunits of ribulose diphosphate carboxylase 总被引:19,自引:0,他引:19
3.
G Bowes W L Ogren R H Hageman 《Biochemical and biophysical research communications》1971,45(3):716-722
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A C Rutner 《Biochemical and biophysical research communications》1970,39(5):923-929
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Daucus carota tissues were grown on Murashige-Skoog medium (MS)at different concentrations with abscisic acid (ABA). Sevenbands of chloroplast fractions were obtained on a sucrose gradient.At 105M, ABA highly increased chlorophyll and proteinnitrogen content of medium density chloroplasts. With increasingage of the tissues, the most active chloroplasts according totheir 14CO2 fixation were found in smaller numbers. When treatedwith 105 M ABA, 34 day-old tissues cultivated in vitroshowed the chloroplast pattern of 110 day-old tissues. The effectof ABAgiven to the tissues during a short pretreatmentor continuously present in the culture mediumon the ribulosediphosphate carboxylase activity was analysed. It was foundthat ABA at 105 M strongly inhibited 14CO2 fixation. (Received December 20, 1977; ) 相似文献
10.
Microenvironmental manipulation of the observed michaelis constant of ribulose diphosphate carboxylase 下载免费PDF全文
Anderson LE 《Plant physiology》1974,54(5):791-793
Urease and ribulose 1, 5-diphosphate carboxylase can be bound to Sepharose to give an immobilized two-enzyme system which catalyzes the reaction urea → H2CO3 → phosphoglyceric acid. The observed Km of the system for urea approaches the lower value for urease when carboxylase levels on the gel exceed urease levels. If a similar system operates in the chloroplast, the high Km (H2CO3) of ribulose 1,5-diphosphate carboxylase may not be metabolically significant. 相似文献
11.
Ribulose diphosphate oxygenase. V. Presence in ribulose diphosphate carboxylase from Rhodospirillum rubrum 总被引:2,自引:0,他引:2
F J Ryan S O Jolly N E Tolbert 《Biochemical and biophysical research communications》1974,59(4):1233-1241
Ribulose-1,5-diphosphate carboxylase was purified fifteenfold from Rhodospirillum rubrum grown autotrophically under H2 and CO2. There was RuDP oxygenase activity associated with the carboxylase. The oxygenase had maximal activity at pH 9.4. Although these bacterial RuDP oxygenase and carboxylase activities were cold labile, activity could not be restored by treatment at 50° in the presence of Mg++ and a sulfhydryl reagent, in contrast to results with the enzyme from eukaryotes. 相似文献
12.
Autotrophic CO2 assimilation and the evolution of ribulose diphosphate carboxylase 总被引:18,自引:0,他引:18
B A McFadden 《Bacteriological reviews》1973,37(3):289-319
13.
Localization and properties of ribulose diphosphate carboxylase from castor bean endosperm 总被引:1,自引:9,他引:1 下载免费PDF全文
A substantial portion of the ribulose 1,5-diphosphate carboxylase activity in the endosperm of germinating castor beans (Ricinus communis var. Hale) is recovered in the proplastid fraction. The partially purified enzyme shows homology with the enzyme from spinach (Spinacia oleracea) leaves, as evidenced by its reaction against antibodies to the native spinach enzyme and to its catalytic subunit. The enzyme from the endosperm of castor beans has a molecular weight of about 500,000 and, with the exception of a higher affinity for ribulose 1,5-diphosphate, has similar kinetic properties to the spinach enzyme. The castor bean carboxylase is inhibited by oxygen and also displays ribulose 1,5-diphosphate oxygenase activity with an optimum at pH 7.5. 相似文献
14.
Changing ribulose diphosphate carboxylase/oxygenase activity in ripening tomato fruit 总被引:3,自引:2,他引:1 下载免费PDF全文
Tomato fruit (Lycopersicum esculentum Mill) from green, pink, and red stages were assayed for changes in the activity of ribulose diphosphate carboxylase and oxygenase, phosphoenolpyruvate carboxylase, changes in the levels of glycolate and respiratory gas exchange. The ribulose diphosphate carboxylase activity decreased as the fruit ripened. By comparison, the ribulose diphosphate oxygenase activity increased during the transition from the green to the pink stage, and declined afterward. The changes in the endogenous glycolate levels and the respiratory gas exchange, as observed at different stages of ripening, resembled the changes in the ribulose diphosphate oxygenase activity. The utilization of glycolate in further metabolic activity may result in the formation of peroxidases required for the onset of ripening. 相似文献
15.
Autotrophic CO2 assimilation and the evolution of ribulose diphosphate carboxylase. 总被引:2,自引:0,他引:2 下载免费PDF全文
B A McFadden 《Microbiological reviews》1973,37(3):289-319
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The distribution of carbonic anhydrase and ribulose diphosphate carboxylase in maize leaves 下载免费PDF全文
Poincelot RP 《Plant physiology》1972,50(3):336-340
Extraction of maize (Zea mays) leaves by progressive grinding under suitably protective conditions yields total carbonic anhydrase activities (4800 units per milligram chlorophyll) comparable to the activity in spinach (Spinacia oleracea) leaves. The total ribulose diphosphate carboxylase activity was also equal to or greater than the best literature values for maize. Of the total leaf carbonic anhydrase, 72.5% on a chlorophyll basis was present in the mesophyll cells and 14.2% in the bundle-sheath cells. The distribution of the total leaf ribulose diphosphate carboxylase between the mesophyll and bundle-sheath cells was 42.0 and 48.7% respectively. There was three times as much total chlorophyll in extracts of the mesophyll cells compared with the bundle-sheath cells of maize. Similar results for the above distribution of the two enzymes were found using a differential grinding technique. The possible function of carbonic anhydrase in photosynthesis is discussed. The equal distribution of ribulose diphosphate carboxylase activity between the mesophyll and bundle-sheath cells casts doubt upon the hypothesis that a rigid biochemical compartmentation exists between these cell types in maize. 相似文献
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Ruth Alscher M.A. Smith L.W. Petersen R.C. Huffaker R.S. Criddle 《Archives of biochemistry and biophysics》1976,174(1):216-225
Polyribosomes isolated from greening barley leaves were active in directing protein synthesis, using soluble components isolated from Escherichia coli. A peptide of 55,000 molecular weight was a major product of translation activity. This peptide was precipitated by antibody to ribulose 1,5-diphosphate carboxylase (RuDPCase) and comigrated with the large subunit of RuDPCase on sodium dodecyl sulfate-polyacrylamide gels. Cyanogen bromide peptides of the peptide of 55,000 molecular weight also corresponded to the peptides prepared from authentic RuDPCase large subunit. The peptides synthesized were shown by sucrose density gradient sedimentation to be largely associated with 70 S ribosomes. 相似文献
20.
The active species of "CO2" utilized by ribulose diphosphate carboxylase 总被引:21,自引:0,他引:21