Relationship between valine, fatty acids, and spiramycin biosynthesis in Streptomyces ambofaciens

1994 ◽  
Vol 40 (8) ◽  
pp. 672-676 ◽  
Author(s):  
Mohamed Laakel ◽  
Ahmed Lebrihi ◽  
Saida Khaoua ◽  
François Schneider ◽  
Gérard Lefebvre ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Kinase Activity ◽  
Antibiotic Production ◽  
Short Chain Fatty Acids ◽  
Acetate Kinase ◽  
Acetyl Coa Carboxylase ◽  
Acetyl Coa ◽  
Active Growth ◽  
Carboxylase Activity ◽  
Streptomyces Ambofaciens

Spiramycin biosynthesis in Streptomyces ambofaciens was stimulated in the presence of valine or by sequential addition of some short-chain fatty acids to a culture medium containing an ammonium salt as source of nitrogen. Acetate kinase and acetyl-CoA carboxylase, enzymes that catalysed the formation of precursors of spiramycin biosynthesis (acetyl-CoA and malonyl-CoA), were detected during the active growth and antibiotic production phases. In this latter phase a higher level of acetyl-CoA carboxylase activity was observed with valine (1.02 μmol∙min−1∙mg protein−1) than with ammonium (0.05 μmol∙min−1∙mg protein−1) as nitrogen source, while the evolution and the level of acetate kinase activity were the same in both media. Successive addition of acetate and isobutyrate stimulated highly and weakly the acetyl-CoA carboxylase and acetate kinase activity, respectively.Key words: spiramycin, Streptomyces ambofaciens, valine.

scholarly journals The sensitivity of acetyl-coenzyme A carboxylase to citrate stimulation in a homogenate of rat liver containing subcellular particles

1970 ◽  
Vol 117 (2) ◽  
pp. 385-395 ◽  
Author(s):  
Jill Iliffe ◽  
N. B. Myant
Keyword(s):  
Fatty Acids ◽  
Rat Liver ◽  
Specific Radioactivity ◽  
Acid Synthesis ◽  
Acetate Incorporation ◽  
Acetyl Coa Carboxylase ◽  
Acetyl Coa ◽  
Carboxylase Activity ◽  
Highly Sensitive ◽  
Activated State

1. Although citrate is known to activate purified preparations of acetyl-CoA carboxylase, it had no stimulatory effect on the incorporation of [14C]acetate into long-chain fatty acids in a whole homogenate of rat liver (S0.7) under conditions in which the activity of acetyl-CoA carboxylase was rate-limiting for fatty acid synthesis. 2. The rate of incorporation of acetyl carbon into fatty acids was estimated in S0.7 preparations incubated with [14C]acetate, by measuring the specific radioactivity of the acetyl carbon of acetyl-CoA and the incorporation of 14C into fatty acids. These estimates were compared with estimates of acetyl-CoA carboxylase activity in the S0.7 preparation obtained by direct assay in conditions in which the enzyme was in the fully activated state. 3. In the absence of citrate, incorporation of acetyl carbon into fatty acids was about 75% of the value expected if the acetyl-CoA carboxylase in the S0.7 preparation were in the fully activated state. 4. Incorporation of acetyl carbon into fatty acids in the S0.7 preparation was stimulated by citrate, but the effect was many times less than the stimulation of [14C]acetate incorporation by citrate in particle-free preparations. 5. When the mitochondria and microsomes were removed from the S0.7 preparation, [14C]acetate incorporation into fatty acids fell to a negligible value and the preparation became highly sensitive to stimulation by citrate. 6. It is suggested that in the presence of mitochondria and microsomes, and in the intact liver cell, the degree of activation of acetyl-CoA carboxylase is such that citrate activation may not be of physiological significance.

scholarly journals Medium-chain fatty acids as short-term regulators of hepatic lipogenesis

1994 ◽  
Vol 302 (1) ◽  
pp. 141-146 ◽  
Author(s):  
M J H Geelen
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Fatty Acid Synthesis ◽  
Acid Synthesis ◽  
Acetyl Coa Carboxylase ◽  
Short Term ◽  
Acetyl Coa ◽  
Carboxylase Activity ◽  
Malonyl Coa ◽  
Stimulation Of

Short-term exposure of isolated rat hepatocytes to short- and medium-chain fatty acids led to an activation of acetyl-CoA carboxylase as measured in digitonin-permeabilized hepatocytes. Up to a certain concentration, typical for each of the fatty acids used, fatty acid-dependent activation of acetyl-CoA carboxylase coincided with an increase in the rate of fatty acid synthesis in intact hepatocytes, as determined by the incorporation of 3H from 3H2O water into fatty acids. At higher concentrations loss of stimulation of fatty acid synthesis occurred, but not the enhancement of carboxylase activity. With the fatty acids tested (C8:0-C14:0), the peak in fatty acid synthesis coincided with a peak in the level of malonyl-CoA. The onset of the stimulation of carboxylase activity coincided with the start of the peak in both fatty acid synthesis and malonyl-CoA. The longer the chain length of the fatty acid added, the lower the concentration at which the rate of fatty acid synthesis and the level of malonyl-CoA reached a peak and carboxylase activity started to become elevated. In cell suspensions incubated with increasing concentrations of fatty acids, accumulation of lactate decreased progressively. The latter observation, in combination with the fact that the activity of acetyl-CoA carboxylase is not always related to the rate of fatty acid biosynthesis, suggests that under these conditions not the activity of the carboxylase but the flux through the glycolytic sequence determines, at least in part, the rate of fatty acid synthesis de novo.

scholarly journals Integrating the extracellular, intracellular, and intercellular metabolic processes of Escherichia coli through glucose saturation, inhibition of the acetyl-CoA carboxylase subunit accA with asRNA, and through quantifying cell to cell quorum-sensing

2019 ◽  
Author(s):  
Tatiana Hillman ◽  
Cory Tobin
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Quorum Sensing ◽  
Bacterial Cell ◽  
Short Chain Fatty Acids ◽  
Short Chain ◽  
Acetyl Coa Carboxylase ◽  
Metabolic Processes ◽  
Acetyl Coa ◽  
Chain Fatty Acids

The study aims to demonstrate the link between bacterial cell metabolism and virulence through integrating the environmental, genetic, and cell to cell signaling molecular processes. Dietary fiber metabolized into glucose, increases the proliferation of intestinal microflora, which augments the outputof the Short Chain Fatty Acids. Bacteria ferment the glucose, from fiber, into Short Chain Fatty Acids, which help regulate many biochemical processes and pathways. Each SCFA maintains colonic pH, promotes cell differentiation, and the apoptosis of colonocytes. To model a high-fiber diet, increasing the synthesis of Acetyl-CoA carboxylase, an enzyme that catabolizes glucose into SCFAs, Escherichia coli was cultured in Luria Broth enhanced with a high to low concentration of glucose. The 15mM, a high concentration of glucose, yielded qPCR products measured, for the target gene accA, which was 4,210ng/µL. The 7.5mM sample produced a concentration equaled to 375 ng/µL, and the 0µM sample measured an accA concentration of 196 ng/µL. The gene accA, 1 of 4 subunits for the Acetyl-CoA Carboxylase enzyme, was suppressed by asRNA, producing a qPCR concentration of 63ng/µL. Antisense RNA for accA reduced the amount of Lux-S, a vital gene needed for propagating quorum-sensing signal molecules. The Lux-S gene, responsible for releasing autoinducer 2 for cell to cell quorum sensing, was reduced by the gene inhibition of accA with asRNA. The increase in Lux-S transcription increases biofilm production for spreading virulence. The further implications of the study propose designing antibiotics that target bacterial cell metabolic processes to block bacterial antibiotic resistance.

scholarly journals Protein-serine kinase from rat epididymal adipose tissue which phosphorylates and activates acetyl-CoA carboxylase. Possible role in insulin action

1990 ◽  
Vol 270 (3) ◽  
pp. 795-801 ◽  
Author(s):  
A C Borthwick ◽  
N J Edgell ◽  
R M Denton
Keyword(s):  
Adipose Tissue ◽  
Insulin Action ◽  
Kinase Activity ◽  
Potent Inhibitor ◽  
Fold Increase ◽  
Epididymal Adipose Tissue ◽  
Acetyl Coa Carboxylase ◽  
Serine Kinase ◽  
Acetyl Coa ◽  
Carboxylase Activity

1. Most of the cyclic-nucleotide-independent acetyl-CoA carboxylase kinase activity in an extract of rat epididymal adipose tissue was evaluated from a Mono Q column by 0.175 M-NaCl at pH 7.4. The activity of the kinase in this fraction (fraction 1) was increased after exposure of intact tissue to insulin. 2. Incubation of purified adipose-tissue acetyl-CoA carboxylase with [gamma-32P]ATP and samples of fraction 1 led to the incorporation of up to 0.4 mol of 32P/mol of enzyme subunit. Most of the phosphorylation was on serine residues within a single tryptic peptide. This peptide, on the basis of two-dimensional t.l.c. analysis, h.p.l.c. and Superose 12 chromatography, appeared to be the same as the acetyl-CoA carboxylase peptide (‘I’-peptide) which exhibits increased phosphorylation in insulin-treated tissue. 3. Phosphorylation of purified acetyl-CoA carboxylase by the kinase in fraction 1 was found to be associated with a parallel 4-fold increase in activity. However, increases in both phosphorylation and activity were much diminished if fraction 1 was treated by Centricon centrifugation to remove low-Mr components. Among these components was a potent inhibitor of acetyl-CoA carboxylase activity which appeared to be necessary for the kinase in fraction 1 to be fully active. 4. The inhibitor remains to be identified, but inhibition requires MgATP, although the inhibitor itself does not cause any phosphorylation of the carboxylase. No effects of insulin were observed on the activity of the inhibitor. 5. It is concluded that the kinase probably plays an important role in the mechanism whereby insulin brings about the well-established increases in phosphorylation and activation of acetyl-CoA carboxylase in adipose tissue.

scholarly journals Integrating the extracellular, intracellular, and intercellular metabolic processes of Escherichia coli through glucose saturation, inhibition of the acetyl-CoA carboxylase subunit accA with asRNA, and through quantifying cell to cell quorum-sensing

2019 ◽  
Author(s):  
Tatiana Hillman ◽  
Cory Tobin
Keyword(s):  
Escherichia Coli ◽  
Fatty Acids ◽  
Quorum Sensing ◽  
Bacterial Cell ◽  
Short Chain Fatty Acids ◽  
Short Chain ◽  
Acetyl Coa Carboxylase ◽  
Metabolic Processes ◽  
Acetyl Coa ◽  
Chain Fatty Acids

The study aims to demonstrate the link between bacterial cell metabolism and virulence through integrating the environmental, genetic, and cell to cell signaling molecular processes. Dietary fiber metabolized into glucose, increases the proliferation of intestinal microflora, which augments the outputof the Short Chain Fatty Acids. Bacteria ferment the glucose, from fiber, into Short Chain Fatty Acids, which help regulate many biochemical processes and pathways. Each SCFA maintains colonic pH, promotes cell differentiation, and the apoptosis of colonocytes. To model a high-fiber diet, increasing the synthesis of Acetyl-CoA carboxylase, an enzyme that catabolizes glucose into SCFAs, Escherichia coli was cultured in Luria Broth enhanced with a high to low concentration of glucose. The 15mM, a high concentration of glucose, yielded qPCR products measured, for the target gene accA, which was 4,210ng/µL. The 7.5mM sample produced a concentration equaled to 375 ng/µL, and the 0µM sample measured an accA concentration of 196 ng/µL. The gene accA, 1 of 4 subunits for the Acetyl-CoA Carboxylase enzyme, was suppressed by asRNA, producing a qPCR concentration of 63ng/µL. Antisense RNA for accA reduced the amount of Lux-S, a vital gene needed for propagating quorum-sensing signal molecules. The Lux-S gene, responsible for releasing autoinducer 2 for cell to cell quorum sensing, was reduced by the gene inhibition of accA with asRNA. The increase in Lux-S transcription increases biofilm production for spreading virulence. The further implications of the study propose designing antibiotics that target bacterial cell metabolic processes to block bacterial antibiotic resistance.

scholarly journals The Two Carboxylases of Corynebacterium glutamicum Essential for Fatty Acid and Mycolic Acid Synthesis

2007 ◽  
Vol 189 (14) ◽  
pp. 5257-5264 ◽  
Author(s):  
Roland Gande ◽  
Lynn G. Dover ◽  
Karin Krumbach ◽  
Gurdyal S. Besra ◽  
Hermann Sahm ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Fatty Acid ◽  
Corynebacterium Glutamicum ◽  
Acid Synthesis ◽  
Mycolic Acid ◽  
Acetyl Coa Carboxylase ◽  
Acetyl Coa ◽  
Carboxylase Activity ◽  
Α Subunit ◽  
Mycolic Acids

ABSTRACT The suborder Corynebacterianeae comprises bacteria like Mycobacterium tuberculosis and Corynebacterium glutamicum, and these bacteria contain in addition to the linear fatty acids, unique α-branched β-hydroxy fatty acids, called mycolic acids. Whereas acetyl-coenzyme A (CoA) carboxylase activity is required to provide malonyl-CoA for fatty acid synthesis, a new type of carboxylase is apparently additionally present in these bacteria. It activates the α-carbon of a linear fatty acid by carboxylation, thus enabling its decarboxylative condensation with a second fatty acid to afford mycolic acid synthesis. We now show that the acetyl-CoA carboxylase of C. glutamicum consists of the biotinylated α-subunit AccBC, the β-subunit AccD1, and the small peptide AccE of 8.9 kDa, forming an active complex of approximately 812,000 Da. The carboxylase involved in mycolic acid synthesis is made up of the two highly similar β-subunits AccD2 and AccD3 and of AccBC and AccE, the latter two identical to the subunits of the acetyl-CoA carboxylase complex. Since AccD2 and AccD3 orthologues are present in all Corynebacterianeae, these polypeptides are vital for mycolic acid synthesis forming the unique hydrophobic outer layer of these bacteria, and we speculate that the two β-subunits present serve to lend specificity to this unique large multienzyme complex.

scholarly journals Critical phosphorylation sites for acetyl-CoA carboxylase activity.

1994 ◽  
Vol 269 (35) ◽  
pp. 22162-22168 ◽  
Author(s):  
J. Ha ◽  
S. Daniel ◽  
S.S. Broyles ◽  
K.H. Kim
Keyword(s):  
Phosphorylation Sites ◽  
Acetyl Coa Carboxylase ◽  
Acetyl Coa ◽  
Carboxylase Activity

Relative Activities of Acetyl-CoA Carboxylase and Fatty Acid Synthetase in Chick Liver: Effects of Dietary Fat

1973 ◽  
Vol 51 (7) ◽  
pp. 1029-1033 ◽  
Author(s):  
Gregory I. Liou ◽  
W. E. Donaldson
Keyword(s):  
Fatty Acid ◽  
Corn Oil ◽  
Fatty Acid Synthetase ◽  
Basal Diet ◽  
Acetyl Coa Carboxylase ◽  
Acetyl Coa ◽  
Carboxylase Activity ◽  
Cytosol Fraction ◽  
Activity Concentrations

The specific activities of acetyl-CoA carboxylase and fatty acid synthetase were measured in the cytosol fraction of livers from chicks fed various levels of corn oil, cottonseed oil, corn-oil free fatty acids, or crude (79%) oleic acid. Activities of both enzymes were depressed by the addition of fat to a fat-free basal diet. The ratios of synthetase to carboxylase activity were greater than unity when up to 4% fat was fed, but less than unity when 8% or higher levels of fat were fed. The depressions of the activities of these enzymes appeared to be unrelated to the dietary level of linoleate. In in vitro experiments, 2 μM concentrations of palmityl-CoA or oleoyl-CoA depressed acetyl-CoA carboxylase activity. Concentrations of 20 μM of these acyl-CoA esters did not affect the activity of fatty acid synthetase.

scholarly journals Growth-hormone-prolactin interactions in the regulation of mammary and adipose-tissue acetyl-CoA carboxylase activity and gene expression in lactating rats

1992 ◽  
Vol 285 (2) ◽  
pp. 469-475 ◽  
Author(s):  
M C Barber ◽  
M T Travers ◽  
E Finley ◽  
D J Flint ◽  
R G Vernon
Keyword(s):  
Adipose Tissue ◽  
Mammary Gland ◽  
Serum Prolactin ◽  
Acetyl Coa Carboxylase ◽  
Acetyl Coa ◽  
Carboxylase Activity ◽  
Total Enzyme Activity ◽  
Mrna Concentration ◽  
Total Enzyme ◽  
Activation Status

The factors and mechanisms responsible for the reciprocal changes in lipogenesis in rat mammary gland and adipose tissue during the lactation cycle have been investigated. Lactation decreased the activation status and mRNA concentration of acetyl-CoA carboxylase in adipose tissue. Litter removal decreased the mRNA concentration of acetyl-CoA carboxylase in the mammary gland and increased the enzyme's mRNA concentration and activation status in adipose tissue. Lowering serum prolactin concentration in lactating rats decreased the amount of mammary acetyl-CoA carboxylase mRNA and increased that of adipose tissue, and increased the activation status of the enzyme in adipose tissue. Decreasing serum growth hormone (GH) alone had little effect on acetyl-CoA carboxylase in lactating rats, although it did lower pup growth rate and serum concentration of insulin-like growth factor-I. Lowering serum GH concentration exacerbated the effects of decreasing serum prolactin on mammary-gland (but not adipose-tissue) acetyl-CoA carboxylase mRNA and further increased the rise in activation status of the adipose-tissue enzyme induced by decreasing serum prolactin. Changes in acetyl-CoA carboxylase mRNA in both mammary and adipose tissue were paralleled by changes in total enzyme activity except after litter removal, when there was a disproportionately large decrease in total enzyme activity of the mammary gland. Thus prolactin has a major and GH a minor role in the regulation of acetyl-CoA carboxylase activity during lactation. Changes in mammary activity in response to prolactin and GH are primarily due to alterations in gene transcription, whereas adaptation in adipose tissue involves both changes in gene transcription and activation status.

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