In vitroPhoto-Oxidation of Pyruvate to Acetyl: A Main Source for the Formation of Acetyl Coenzyme A in the Citric Acid Cycle to Perform Biochemical Reactions

2013 ◽  
Vol 60 (6) ◽  
pp. 671-676 ◽  
Author(s):  
Muhammad Akhyar Farrukh ◽  
Sana Naz
Keyword(s):  
Citric Acid ◽  
Citric Acid Cycle ◽  
Coenzyme A ◽  
Biochemical Reactions ◽  
Acetyl Coenzyme A ◽  
Acid Cycle ◽  
Acetyl Coenzyme

Enzymic synthesis of L-acetylcarnitine and citric acid using acetyl coenzyme A recycling

1986 ◽  
Vol 51 (14) ◽  
pp. 2842-2844 ◽  
Author(s):  
Smita S. Patel ◽  
Hugh D. Conlon ◽  
David R. Walt
Keyword(s):  
Citric Acid ◽  
Coenzyme A ◽  
Acetyl Coenzyme A ◽  
Enzymic Synthesis ◽  
Acetyl Coenzyme

THE ENZYMATIC SYNTHESIS OF CITRIC ACID BY CELL-FREE EXTRACTS OF ASPERGILLUS NIGER

1954 ◽  
Vol 32 (4) ◽  
pp. 434-439 ◽  
Author(s):  
C. V. Ramakrishnan ◽  
S. M. Martin
Keyword(s):  
Citric Acid ◽  
Calcium Phosphate ◽  
Aspergillus Niger ◽  
Ammonium Sulphate ◽  
Enzymatic Synthesis ◽  
Coenzyme A ◽  
Acetyl Coenzyme A ◽  
Acetyl Coenzyme ◽  
Ammonium Sulphate Fractionation ◽  
Condensing Enzyme

Cell-free extracts of Aspergillus niger, N.R.C. 233, have been shown to contain the enzymes necessary to catalyze the synthesis of citrate from ATP, acetate, and oxalacetate. The "condensing enzyme", which catalyzes the condensation of acetyl-coenzyme A and oxalacetate to yield citrate, has been isolated and purified approximately 50-fold by a combination of steps involving ammonium sulphate fractionation and calcium phosphate gel adsorption.

THE ENZYMATIC SYNTHESIS OF CITRIC ACID BY CELL-FREE EXTRACTS OF ASPERGILLUS NIGER

1954 ◽  
Vol 32 (1) ◽  
pp. 434-439 ◽  
Author(s):  
C. V. Ramakrishnan ◽  
S. M. Martin
Keyword(s):  
Citric Acid ◽  
Calcium Phosphate ◽  
Aspergillus Niger ◽  
Ammonium Sulphate ◽  
Enzymatic Synthesis ◽  
Coenzyme A ◽  
Acetyl Coenzyme A ◽  
Acetyl Coenzyme ◽  
Ammonium Sulphate Fractionation ◽  
Condensing Enzyme

Cell-free extracts of Aspergillus niger, N.R.C. 233, have been shown to contain the enzymes necessary to catalyze the synthesis of citrate from ATP, acetate, and oxalacetate. The "condensing enzyme", which catalyzes the condensation of acetyl-coenzyme A and oxalacetate to yield citrate, has been isolated and purified approximately 50-fold by a combination of steps involving ammonium sulphate fractionation and calcium phosphate gel adsorption.

scholarly journals A Specialized Citric Acid Cycle Requiring Succinyl-Coenzyme A (CoA):Acetate CoA-Transferase (AarC) Confers Acetic Acid Resistance on the Acidophile Acetobacter aceti

2008 ◽  
Vol 190 (14) ◽  
pp. 4933-4940 ◽  
Author(s):  
Elwood A. Mullins ◽  
Julie A. Francois ◽  
T. Joseph Kappock
Keyword(s):  
Acetic Acid ◽  
Citric Acid ◽  
Citric Acid Cycle ◽  
Coenzyme A ◽  
Acid Resistance ◽  
Acetic Acid Bacteria ◽  
Acetobacter Aceti ◽  
Acid Cycle ◽  
Coa Transferase ◽  
Acetic Acid Resistance

ABSTRACT Microbes tailor macromolecules and metabolism to overcome specific environmental challenges. Acetic acid bacteria perform the aerobic oxidation of ethanol to acetic acid and are generally resistant to high levels of these two membrane-permeable poisons. The citric acid cycle (CAC) is linked to acetic acid resistance in Acetobacter aceti by several observations, among them the oxidation of acetate to CO2 by highly resistant acetic acid bacteria and the previously unexplained role of A. aceti citrate synthase (AarA) in acetic acid resistance at a low pH. Here we assign specific biochemical roles to the other components of the A. aceti strain 1023 aarABC region. AarC is succinyl-coenzyme A (CoA):acetate CoA-transferase, which replaces succinyl-CoA synthetase in a variant CAC. This new bypass appears to reduce metabolic demand for free CoA, reliance upon nucleotide pools, and the likely effect of variable cytoplasmic pH upon CAC flux. The putative aarB gene is reassigned to SixA, a known activator of CAC flux. Carbon overflow pathways are triggered in many bacteria during metabolic limitation, which typically leads to the production and diffusive loss of acetate. Since acetate overflow is not feasible for A. aceti, a CO2 loss strategy that allows acetic acid removal without substrate-level (de)phosphorylation may instead be employed. All three aar genes, therefore, support flux through a complete but unorthodox CAC that is needed to lower cytoplasmic acetate levels.

Lack of Citrate Lyase — the Key Enzyme of the Reductive Carboxylic Acid Cycle — in Chlorobium thiosulfatophilum and Rhodospirillum rubrum

1972 ◽  
Vol 27 (8) ◽  
pp. 967-973 ◽  
Author(s):  
Norbert Beuscher ◽  
Gerhard Gottschalk
Keyword(s):  
Carboxylic Acid ◽  
Rhodospirillum Rubrum ◽  
Coenzyme A ◽  
Reaction Sequence ◽  
Acetyl Coenzyme A ◽  
Acid Cycle ◽  
Acetyl Coenzyme ◽  
Citrate Lyase ◽  
Chlorobium Thiosulfatophilum ◽  
Key Enzyme

Extracts of Chlorobium thiosulfatophilum and of Rhodospirillum rubrum have been tested for the presence of citrate lyase under various conditions. This enzyme could not be detected. It is, therefore, concluded that a complete reductive carboxylic acid cycle does not occur in these microorganisms.The enzymes required for a-ketoglutarate synthesis from oxaloaetate and acetyl-coenzyme A are present in autotrophically grown cells of C. thiosulfatophilum and R. rubrum. This supports the view that a reaction sequence catalyzing the conversion of α-ketoglutarate into oxaloacetate is unlikely to exist in these bacteria.

Enzyme-catalyzed synthesis of citric acid using acetyl-coenzyme a recycling in a two-phase system

1990 ◽  
Vol 18 (2) ◽  
pp. 131-135 ◽  
Author(s):  
Tianmei Ouyang ◽  
David R. Walt ◽  
Smita S. Patel
Keyword(s):  
Citric Acid ◽  
Coenzyme A ◽  
Phase System ◽  
Two Phase ◽  
Acetyl Coenzyme A ◽  
Acetyl Coenzyme

EFFECT OF SERUM GONADOTROPHIN ON DEHYDROGENASES OF THE CITRIC ACID CYCLE IN THE OVARY OF THE RAT

1963 ◽  
Vol 42 (4) ◽  
pp. 480-484 ◽  
Author(s):  
B. Eckstein ◽  
R. Landsberg
Keyword(s):  
Citric Acid ◽  
Citric Acid Cycle ◽  
Age Groups ◽  
Succinic Dehydrogenase ◽  
Immature Rat ◽  
Acid Cycle ◽  
Immature Rats ◽  
Rat Ovary

ABSTRACT The succinic, malic and isocitric dehydrogenases in the ovary of immature and mature, normal and serum gonadotrophin injected rats were examined. The Qo2 of these enzymes were markedly enhanced in the gonadotrophin injected rats of both age groups, except in the case of succinic dehydrogenase in the ovary of the immature rats, where a slight non-significant decrease was noted. It is concluded that in the mature rat ovary, gonadotrophin administration stimulates the activity of all the examined dehydrogenases of the citric acid cycle, whereas in the immature rat ovary, at least the isocitric- and malic dehydrogenases are thus stimulated.

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