scholarly journals Properties and substrate specificity of some reactions catalysed by a short-chain fatty acyl-coenzyme A synthetase from seeds of Pinus radiata

1974 ◽  
Vol 137 (3) ◽  
pp. 423-433 ◽  
Author(s):  
Owen A. Young ◽  
John W. Anderson
Keyword(s):  
Fatty Acid ◽  
Pinus Radiata ◽  
Fatty Acyl ◽  
Short Chain ◽  
Synthetase Activity ◽  
Long Chain Fatty Acid ◽  
Acetyl Coa ◽  
Crude Extracts ◽  
Acyl Coenzyme A ◽  
Single Enzyme

1. Crude extracts of seeds of Pinus radiata catalysed acetate-, propionate-, n-butyrate- and n-valerate-dependent PPi–ATP exchange in the presence of MgCl2, which was apparently due to a single enzyme. Propionate was the preferred substrate. Crude extracts did not catalyse medium-chain or long-chain fatty acid-dependent exchange. 2. Ungerminated dry seeds contained short-chain fatty acyl-CoA synthetase activity. The activity per seed was approximately constant for 11 days after imbibition and then declined. The enzyme was located only in the female gametophyte tissue. 3. The synthetase was purified 70-fold. 4. Some properties of the enzyme were studied by [32P]PPi–ATP exchange. Km values for acetate, propionate, n-butyrate and n-valerate were 4.7, 0.21, 0.33 and 2.1mm respectively. Competition experiments between acetate and propionate demonstrated that only one enzyme was involved and confirmed that the affinity of the enzyme for propionate was greater than that for acetate. CoA inhibited fatty acid-dependent PPi–ATP exchange. The enzyme catalysed fatty acid-dependent [32P]PPi–dATP exchange. 5. The enzyme also catalysed the fatty acyl-AMP-dependent synthesis of [32P]ATP from [32P]PPi. Apparent Km (acetyl-AMP) and apparent Km (propionyl-AMP) were 57μm and 7.5μm respectively. The reaction was inhibited by AMP and CoA. 6. Purified enzyme catalysed the synthesis of acetyl-CoA and propionyl-CoA. Apparent Km (acetate) and apparent Km (propionate) were 16mm and 7.5mm respectively. The rate of formation of acetyl-CoA was enhanced by pyrophosphatase. 7. It was concluded that fatty acyl adenylates are intermediates in the formation of the corresponding fatty acyl-CoA.

scholarly journals The enzymology of short-chain fatty acyl-coenzyme A synthetase from seeds of Pinus radiata. Kinetic studies and a proposed reaction mechanism

1974 ◽  
Vol 137 (3) ◽  
pp. 435-442 ◽  
Author(s):  
Owen A. Young ◽  
John W. Anderson
Keyword(s):  
Fatty Acid ◽  
Pinus Radiata ◽  
Kinetic Studies ◽  
Single Species ◽  
Competitive Inhibitor ◽  
Fatty Acyl ◽  
Short Chain ◽  
Low Concentrations ◽  
High Concentrations ◽  
Acyl Coenzyme A

1. Short-chain fatty acyl-CoA synthetase from seeds of Pinus radiata was examined by acetate- and propionate-dependent PPi–ATP exchange. Reaction mixtures came to equilibrium almost instantly as judged by rates of exchange and analysis of an incubation mixture. 2. The activity of the enzyme was correlated with the concentration of MgP2O72- but not with the concentration of Mg2+, as judged by PPi–ATP exchange and fatty acyl AMP-dependent synthesis of ATP in the presence of PPi. In PPi–ATP exchange assays, no clear relationship between activity and any single species of ATP was apparent. 3. High concentrations of fatty acid inhibited PPi–ATP exchange. PPi–dATP exchange was less than PPi–ATP exchange at low concentrations of fatty acid, but at higher concentrations PPi–dATP exchange exceeded PPi–ATP exchange. The rate of synthesis of fatty acyl-CoA in the presence of dATP was less than with ATP. 4. ATP and propionate inhibited the synthesis of ATP from propionyl-AMP and PPi. The inhibition by ATP was competitive with respect to propionyl-AMP and non-competitive with respect to PPi. The inhibition by propionate was non-competitive with respect to propionyl-AMP and PPi. 5. AMP was a competitive inhibitor of propionyl-AMP-dependent synthesis of ATP and competitively inhibited propionate-dependent PPi–ATP exchange when ATP was the variable substrate. 6. It was concluded that the first partial reaction catalysed by the enzyme is ordered; ATP is the first substrate to react with the enzyme and PPi is probably the only product released.

scholarly journals Disruption of theSaccharomyces cerevisiae FAT1Gene Decreases Very Long-chain Fatty Acyl-CoA Synthetase Activity and Elevates Intracellular Very Long-chain Fatty Acid Concentrations

1998 ◽  
Vol 273 (29) ◽  
pp. 18210-18219 ◽  
Author(s):  
Paul A. Watkins ◽  
Jyh-Feng Lu ◽  
Steven J. Steinberg ◽  
Stephen J. Gould ◽  
Kirby D. Smith ◽  
...  
Keyword(s):  
Fatty Acid ◽  
Fatty Acyl ◽  
Chain Fatty Acid ◽  
Synthetase Activity ◽  
Long Chain Fatty Acid ◽  
Long Chain

scholarly journals Transcriptional Regulation by the Short-Chain Fatty Acyl Coenzyme A Regulator (ScfR) PccR Controls Propionyl Coenzyme A Assimilation by Rhodobacter sphaeroides

2015 ◽  
Vol 197 (19) ◽  
pp. 3048-3056 ◽  
Author(s):  
Michael S. Carter ◽  
Birgit E. Alber
Keyword(s):  
Rhodobacter Sphaeroides ◽  
Coenzyme A ◽  
Bacterial Species ◽  
Fatty Acyl ◽  
Short Chain ◽  
Coding Region ◽  
Acetyl Coa ◽  
Content Type ◽  
Chain Acyl ◽  
Acyl Coenzyme A

ABSTRACTPropionyl coenzyme A (propionyl-CoA) assimilation byRhodobacter sphaeroidesproceeds via the methylmalonyl-CoA pathway. The activity of the key enzyme of the pathway, propionyl-CoA carboxylase (PCC), was upregulated 20-fold during growth with propionate compared to growth with succinate. Because propionyl-CoA is an intermediate in acetyl-CoA assimilation via the ethylmalonyl-CoA pathway, acetate growth also requires the methylmalonyl-CoA pathway. PCC activities were upregulated 8-fold in extracts of acetate-grown cells compared to extracts of succinate-grown cells. The upregulation of PCC activities during growth with propionate or acetate corresponded to increased expression of thepccBgene, which encodes a subunit of PCC. PccR (RSP_2186) was identified to be a transcriptional regulator required for the upregulation ofpccBtranscript levels and, consequently, PCC activity: growth substrate-dependent regulation was lost whenpccRwas inactivated by an in-frame deletion. In thepccRmutant,lacZexpression from a 215-bp plasmid-bornepccBupstream fragment including 27 bp of thepccBcoding region was also deregulated. A loss of regulation as a result of mutations in the conserved motifs TTTGCAAA-X4-TTTGCAAA in the presence of PccR allowed the prediction of a possible operator site. PccR, together with homologs from other organisms, formed a distinct clade within the family ofshort-chainfatty acyl coenzyme Aregulators (ScfRs) defined here. Some members from other clades within the ScfR family have previously been shown to be involved in regulating acetyl-CoA assimilation by the glyoxylate bypass (RamB) or propionyl-CoA assimilation by the methylcitrate cycle (MccR).IMPORTANCEShort-chain acyl-CoAs are intermediates in essential biosynthetic and degradative pathways. The regulation of their accumulation is crucial for appropriate cellular function. This work identifies a regulator (PccR) that prevents the accumulation of propionyl-CoA by controlling expression of the gene encoding propionyl-CoA carboxylase, which is responsible for propionyl-CoA consumption byRhodobacter sphaeroides. Many otherProteobacteriaandActinomycetalescontain one or several PccR homologs that group into distinct clades on the basis of the pathway of acyl-CoA metabolism that they control. Furthermore, an upstream analysis of genes encoding PccR homologs allows the prediction of conserved binding motifs for these regulators. Overall, this study evaluates a single regulator of propionyl-CoA assimilation while expanding the knowledge of the regulation of short-chain acyl-CoAs in many bacterial species.

scholarly journals Cryptosporidium parvum Long-Chain Fatty Acid Elongase

2007 ◽  
Vol 6 (11) ◽  
pp. 2018-2028 ◽  
Author(s):  
Jason M. Fritzler ◽  
Jason J. Millership ◽  
Guan Zhu
Keyword(s):  
Fatty Acid ◽  
Functional Characterization ◽  
Fatty Acyl ◽  
Chain Fatty Acid ◽  
Type I ◽  
Long Chain Fatty Acid ◽  
Fatty Acid Elongase ◽  
Key Enzyme ◽  
Acyl Coenzyme A ◽  
Long Chain

ABSTRACT We report the presence of a new fatty acyl coenzyme A (acyl-CoA) elongation system in Cryptosporidium and the functional characterization of the key enzyme, a single long-chain fatty acid elongase (LCE), in this parasite. This enzyme contains conserved motifs and predicted transmembrane domains characteristic to the elongase family and is placed within the ELO6 family specific for saturated substrates. CpLCE1 gene transcripts are present at all life cycle stages, but the levels are highest in free sporozoites and in stages at 36 h and 60 h postinfection that typically contain free merozoites. Immunostaining revealed localization to the outer surface of sporozoites and to the parasitophorous vacuolar membrane. Recombinant CpLCE1 displayed allosteric kinetics towards malonyl-CoA and palmitoyl-CoA and Michaelis-Menten kinetics towards NADPH. Myristoyl-CoA (C14:0) and palmitoyl-CoA (C16:0) display the highest activity when used as substrates, and only one round of elongation occurs. CpLCE1 is fairly resistant to cerulenin, an inhibitor for both type I and II fatty acid synthases (i.e., maximum inhibitions of 20.5% and 32.7% were observed when C16:0 and C14:0 were used as substrates, respectively). These observations ultimately validate the function of CpLCE1.

Expression Profile of Acetyl CoA Carboxylase Beta (ACACB) Gene during the Pre and Post-hatch Period in Chicken

2021 ◽  
Author(s):  
Ch. Shiva Prasad ◽  
R. Vinoo ◽  
R.N. Chatterjee ◽  
M. Muralidhar ◽  
D. Narendranath ◽  
...  
Keyword(s):  
Gene Expression ◽  
Fatty Acid ◽  
Expression Pattern ◽  
Fatty Acyl ◽  
Acid Oxidation ◽  
Acetyl Coa Carboxylase ◽  
Acetyl Coa ◽  
Layer Chicken ◽  
Differential Expression Pattern ◽  
Long Chain

Background: Acetyl-CoA Carboxylase Beta (ACACB) plays a key role in fatty acid oxidation and was known to be involved in production of very-long-chain fatty acid and other compounds needed for proper development. This gene is mainly expressed in the tissues of heart, muscle, liver and colon. It chiefly involved in the production of malonyl-coA, a potent inhibitor of carnitine palmitoyl transferase I (CPT-I) enzyme needed in transport of long-chain fatty acyl-coAs to the mitochondria for β-oxidation.Methods: The present study was conducted to explore the expression pattern of the ACACB gene in breast muscle tissue during pre-hatch embryonic day (ED) 5th to 18th and post-hatch (18th, 22nd and 40th week of age) periods of White leghorn (IWI line) by using Quantitative real-time PCR (qPCR). Then, fold change of ACACB gene expression was calculated.Result: Our study showed that the ACACB gene expression was down-regulated during embryonic stages from ED6 to ED18. The gene expression was also down-regulated during adult stages i.e. on 22nd and 40th week of age. This result indicated that the initial expression of the ACACB gene is required for embryo development and during adult periods, low gene expression leads to the less fat deposition in muscle of layer chicken. Finally, it can be concluded that there was a differential expression pattern of the ACACB gene during the pre-hatch embryonic and post-hatch adult periods to mitigate varied requirements of lipids during different physiological stages in layer chicken.

Glucose-6-phosphate dehydrogenase from Neisseria gonorrhoeae: partial characterization of the enzyme and inhibition by long-chain fatty acid acyl-coenzyme A derivatives

1980 ◽  
Vol 26 (8) ◽  
pp. 863-873 ◽  
Author(s):  
Anthony F. Cacciapuoti ◽  
Stephen A. Morse
Keyword(s):  
Fatty Acid ◽  
Neisseria Gonorrhoeae ◽  
Coenzyme A ◽  
Energy Charge ◽  
Chain Fatty Acid ◽  
Adenylate Energy Charge ◽  
Long Chain Fatty Acid ◽  
Acyl Coenzyme A ◽  
Glucose 6 Phosphate Dehydrogenase ◽  
Long Chain

The glucose-6-phosphate dehydrogenase from Neisseria gonorrhoeae was inhibited by long-chain fatty acid acyl-coenzyme A derivatives. The inhibition was increased at low concentrations of glucose 6-phosphate and was greater with the NAD-linked activity (ca. 0.05 mM inhibitor required for 50% inhibition) than with the NADP-linked activity (ca. 0.2 mM required for 50% inhibition). Bovine serum albumin and spermine could prevent the inhibition by the acyl-coenzyme A derivatives, but neither of these compounds nor high concentrations of cofactors or substrate could reverse the effect. Dilution of enzyme–inhibitor preincubation mixtures appeared to reverse the inhibition. The inhibition by stearoyl-coenzyme A was of the mixed type, and the inhibitor appeared to have a greater affinity for the free enzyme (Ki = 0.016–0.05 mM) than for enzyme bound to cofactor or substrate (Kis = 0.07–0.08 mM). Glucose-6-phosphate dehydrogenase activity was also inhibited competitively by adenosine 5′-triphosphate and was strongly regulated by adenylate energy charge values between 0.9 and 1.0. Kinetic and other characteristics of the enzyme are presented, and the possible role of glucose-6-phosphate dehydrogenase as a target for fatty acid toxicity in gonococci, mediated in the form of the acyl-coenzyme A derivatives, is discussed.

scholarly journals Steady-state concentrations of coenzyme A, acetyl-coenzyme A and long-chain fatty acyl-coenzyme A in rat-liver mitochondria oxidizing palmitate

1965 ◽  
Vol 97 (2) ◽  
pp. 587-594 ◽  
Author(s):  
PB Garland ◽  
D Shepherd ◽  
DW Yates
Keyword(s):  
Rat Liver ◽  
Coenzyme A ◽  
Liver Mitochondria ◽  
Fatty Acyl ◽  
Rat Liver Mitochondria ◽  
Beta Oxidation ◽  
Acetyl Coa ◽  
Acetyl Coenzyme A ◽  
Acyl Coenzyme A ◽  
Long Chain

1. Fluorimetric assays are described for CoASH, acetyl-CoA and long-chain fatty acyl-CoA, and are sensitive to at least 50mumumoles of each. 2. Application of these assays to rat-liver mitochondria oxidizing palmitate in the absence and presence of carnitine indicated two pools of intramitochondrial CoA. One pool could be acylated by palmitate and ATP, and the other pool acylated by palmitate with ATP and carnitine, or by palmitoylcarnitine alone. 3. The intramitochondrial content of acetyl-CoA is increased by the oxidation of palmitate both in the absence and presence of l-malate. 4. The conversion of palmitoyl-CoA into acetyl-CoA by beta-oxidation takes place without detectable accumulation of acyl-CoA intermediates.

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