scholarly journals Malonyl-Coenzyme A Reductase in the Modified 3-Hydroxypropionate Cycle for Autotrophic Carbon Fixation in Archaeal Metallosphaera and Sulfolobus spp.

2006 ◽  
Vol 188 (24) ◽  
pp. 8551-8559 ◽  
Author(s):  
Birgit Alber ◽  
Marc Olinger ◽  
Annika Rieder ◽  
Daniel Kockelkorn ◽  
Björn Jobst ◽  
...  
Keyword(s):  
Amino Acid ◽  
Carbon Fixation ◽  
Coenzyme A ◽  
Reductase Activity ◽  
Growth Conditions ◽  
Significant Similarity ◽  
Semialdehyde Dehydrogenase ◽  
Malonyl Coa ◽  
Taxonomic Groups ◽  
Coa Reductase

ABSTRACT Autotrophic members of the Sulfolobales (Crenarchaeota) contain acetyl-coenzyme A (CoA)/propionyl-CoA carboxylase as the CO2 fixation enzyme and use a modified 3-hydroxypropionate cycle to assimilate CO2 into cell material. In this central metabolic pathway malonyl-CoA, the product of acetyl-CoA carboxylation, is further reduced to 3-hydroxypropionate. Extracts of Metallosphaera sedula contained NADPH-specific malonyl-CoA reductase activity that was 10-fold up-regulated under autotrophic growth conditions. Malonyl-CoA reductase was partially purified and studied. Based on N-terminal amino acid sequencing the corresponding gene was identified in the genome of the closely related crenarchaeum Sulfolobus tokodaii. The Sulfolobus gene was cloned and heterologously expressed in Escherichia coli, and the recombinant protein was purified and studied. The enzyme catalyzes the following reaction: malonyl-CoA + NADPH + H+ → malonate-semialdehyde + CoA + NADP+. In its native state it is associated with small RNA. Its activity was stimulated by Mg2+ and thiols and inactivated by thiol-blocking agents, suggesting the existence of a cysteine adduct in the course of the catalytic cycle. The enzyme was specific for NADPH (Km = 25 μM) and malonyl-CoA (Km = 40 μM). Malonyl-CoA reductase has 38% amino acid sequence identity to aspartate-semialdehyde dehydrogenase, suggesting a common ancestor for both proteins. It does not exhibit any significant similarity with malonyl-CoA reductase from Chloroflexus aurantiacus. This shows that the autotrophic pathway in Chloroflexus and Sulfolobaceae has evolved convergently and that these taxonomic groups have recruited different genes to bring about similar metabolic processes.

scholarly journals Malonic Semialdehyde Reductase, Succinic Semialdehyde Reductase, and Succinyl-Coenzyme A Reductase from Metallosphaera sedula: Enzymes of the Autotrophic 3-Hydroxypropionate/4-Hydroxybutyrate Cycle in Sulfolobales

2009 ◽  
Vol 191 (20) ◽  
pp. 6352-6362 ◽  
Author(s):  
Daniel Kockelkorn ◽  
Georg Fuchs
Keyword(s):  
Alcohol Dehydrogenase ◽  
Carbon Fixation ◽  
Coenzyme A ◽  
Succinic Semialdehyde ◽  
Metallosphaera Sedula ◽  
Semialdehyde Dehydrogenase ◽  
Malonyl Coa ◽  
Hydroxyacyl Coa Dehydrogenase ◽  
Coa Reductase ◽  
Coenzyme A Reductase

ABSTRACT A 3-hydroxypropionate/4-hydroxybutyrate cycle operates during autotrophic CO2 fixation in various members of the Crenarchaea. In this cycle, as determined using Metallosphaera sedula, malonyl-coenzyme A (malonyl-CoA) and succinyl-CoA are reductively converted via their semialdehydes to the corresponding alcohols 3-hydroxypropionate and 4-hydroxybutyrate. Here three missing oxidoreductases of this cycle were purified from M. sedula and studied. Malonic semialdehyde reductase, a member of the 3-hydroxyacyl-CoA dehydrogenase family, reduces malonic semialdehyde with NADPH to 3-hydroxypropionate. The latter compound is converted via propionyl-CoA to succinyl-CoA. Succinyl-CoA reduction to succinic semialdehyde is catalyzed by malonyl-CoA/succinyl-CoA reductase, a promiscuous NADPH-dependent enzyme that is a paralogue of aspartate semialdehyde dehydrogenase. Succinic semialdehyde is then reduced with NADPH to 4-hydroxybutyrate by succinic semialdehyde reductase, an enzyme belonging to the Zn-dependent alcohol dehydrogenase family. Genes highly similar to the Metallosphaera genes were found in other members of the Sulfolobales. Only distantly related genes were found in the genomes of autotrophic marine Crenarchaeota that may use a similar cycle in autotrophic carbon fixation.

scholarly journals INHIBITION OF 3-HYDROXY-3-METHYLGLUTARYL-COENZYME A REDUCTASE ACTIVITY BY EXTRACTS OF GARCINIA XANTHOCHYMUS MESOCARP AND TOTAL FLAVONOID ASSAY QUANTIFICATION OF THE MOST ACTIVE EXTRACT

2018 ◽  
Vol 10 (1) ◽  
pp. 264
Author(s):  
Megawati . ◽  
Berna Elya ◽  
Nuraini Puspitasari
Keyword(s):  
Ethyl Acetate ◽  
Coenzyme A ◽  
Ethyl Acetate Extract ◽  
Reductase Activity ◽  
Total Flavonoid ◽  
Phytochemical Screening ◽  
Methanol Extracts ◽  
Garcinia Xanthochymus ◽  
Inhibitory Activities ◽  
Coa Reductase

Objective: This study aims to determine the inhibitory activity of Garcinia xanthochymus mesocarp extracts against 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase.Methods: G. xanthochymus mesocarp was macerated sequentially using n-hexane, ethyl acetate, and methanol. Phytochemical screening andquantification of total flavonoids were performed on the most active extract.Results: Based on the tests, n-hexane, ethyl acetate, and methanol extracts had inhibitory activities of 12.30±1.098%, 55.63±10.584%, and44.01±1.053%, respectively. The results showed that the ethyl acetate is the most active extract, containing flavonoid, terpenoid, glycoside, andanthraquinone compounds. The amount of total flavonoid contained in ethyl acetate extract was 1.61% or 16.114 mg QE/g toward quercetin.Conclusion: The n-hexane, ethyl acetate, and methanol extracts of G. xanthochymus have inhibitory actions against HMG-CoA reductase activityin vitro. Further research is still needed to strengthen this finding.

scholarly journals A new method for assaying rat liver microsomal 3-hydroxy-3-methylglutaryl-coenzyme A reductase activity and its application in a study of the effect of dietary cholesterol on this effect of dietary cholesterol on this enzyme

1977 ◽  
Vol 164 (3) ◽  
pp. 501-508 ◽  
Author(s):  
Y A Baqir ◽  
R Booth
Keyword(s):  
Rat Liver ◽  
Cholesterol Ester ◽  
Time Course ◽  
Coenzyme A ◽  
Reductase Activity ◽  
Dietary Cholesterol ◽  
New Method ◽  
Coa Reductase ◽  
Microsomal Cholesterol ◽  
Coenzyme A Reductase

A new method suitable for measuring rat liver 3-hydroxy-3-methylglutaryl-CoA reductase activity is described and its advantages over methods previously available are discussed. An accurate time course was measured for the inhibition of liver microsomal 3-hydroxy-3-methylglutaryl-CoA reductase activity by dietary cholesterol; this enzyme was affected 1 1/4 h after the rats began to consume a cholesterol-rich diet. In this experiment there was no correlation between concentrations of microsomal cholesterol ester and the activity of 3-hydroxy-3-methylglutary-CoA reductase.

scholarly journals Purification, Characterization, and Cloning of a Eubacterial 3-Hydroxy-3-Methylglutaryl Coenzyme A Reductase, a Key Enzyme Involved in Biosynthesis of Terpenoids

1999 ◽  
Vol 181 (4) ◽  
pp. 1256-1263 ◽  
Author(s):  
Shunji Takahashi ◽  
Tomohisa Kuzuyama ◽  
Haruo Seto
Keyword(s):  
Amino Acid ◽  
Coenzyme A ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Gel Filtration ◽  
Ph Optimum ◽  
Hmg Coa Reductase ◽  
Apparent Homogeneity ◽  
Key Enzyme ◽  
Coa Reductase

ABSTRACT The eubacterial 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase (EC 1.1.1.34 ) was purified 3,000-fold fromStreptomyces sp. strain CL190 to apparent homogeneity with an overall yield of 2.1%. The purification procedure consisted of (NH4)2SO4 precipitation, heat treatment and anion exchange, hydrophobic interaction, and affinity chromatographies. The molecular mass of the enzyme was estimated to be 41 kDa by sodium dodecyl sulfate-polyacrylamide gel electrophoresis and 100 to 105 kDa by gel filtration chromatography, suggesting that the enzyme is most likely to be a dimer. The enzyme showed a pH optimum of around 7.2, with apparent Km values of 62 μM for NADPH and 7.7 μM for HMG-CoA. A gene from CL190 responsible for HMG-CoA reductase was cloned by the colony hybridization method with an oligonucleotide probe synthesized on the basis of the N-terminal sequence of the purified enzyme. The amino acid sequence of the CL190 HMG-CoA reductase revealed several limited motifs which were highly conserved and common to the eucaryotic and archaebacterial enzymes. These sequence conservations suggest a strong evolutionary pressure to maintain amino acid residues at specific positions, indicating that the conserved motifs might play important roles in the structural conformation and/or catalytic properties of the enzyme.

scholarly journals Emergence of W272C Substitution in Hmg1 in a Triazole-Resistant Isolate of Aspergillus fumigatus from a Chinese Patient with Chronic Cavitary Pulmonary Aspergillosis

2021 ◽  
Author(s):  
Tianyu Liang ◽  
Xinyu Yang ◽  
Ruoyu Li ◽  
Ence Yang ◽  
Qiqi Wang ◽  
...  
Keyword(s):  
Amino Acid ◽  
Aspergillus Fumigatus ◽  
Amino Acid Substitution ◽  
Coenzyme A ◽  
Chinese Patient ◽  
Resistant Isolate ◽  
Pulmonary Aspergillosis ◽  
First Case ◽  
Reductase Gene ◽  
Coa Reductase

Recently, mutations in the 3-hydroxy-3-methyl-glutaryl-coenzyme A (HMG-CoA) reductase gene (hmg1) have been identified to be associated with triazole resistance in Aspergillus fumigatus. Here, we describe the first case of the G929C mutation in the hmg1 gene, leading to the W272C amino acid substitution, in a triazole-resistant isolate of A. fumigatus recovered from a chronic cavitary pulmonary aspergillosis patient who failed voriconazole therapy in China.

scholarly journals Inhibition of hydroxymethylglutaryl coenzyme A reductase activity induces a paradoxical increase in DNA synthesis in myeloid leukemia cells

Blood ◽  
1991 ◽  
Vol 77 (5) ◽  
pp. 1064-1070 ◽  
Author(s):  
RJ Hohl ◽  
RA Larson ◽  
V Mannickarottu ◽  
S Yachnin
Keyword(s):  
Dna Synthesis ◽  
Myeloid Leukemia ◽  
Coenzyme A ◽  
Reductase Activity ◽  
Myelogenous Leukemia ◽  
Leukemia Cells ◽  
Hmg Coa Reductase ◽  
Cellular Dna ◽  
Coa Reductase ◽  
Inhibition Of Dna Synthesis

Abstract The effects of competitive inhibition of hydroxymethylglutaryl coenzyme A (HMG CoA) reductase by compactin on the in vitro proliferation of peripheral blood myeloid leukemia cells were studied using the cells from 45 patients with acute myeloid leukemia or chronic myelogenous leukemia in blast phase. The cells from 58% of these patients showed a dose-related inhibition of DNA synthesis when incubated with compactin. Unexpectedly, cells from 18% of the patients were resistant to the inhibitory effects of compactin on DNA synthesis and responded to the HMG CoA reductase inhibition with an actual increase in the incorporation of 14C-labeled thymidine into DNA. Another 18% of the patients studied displayed both inhibition and stimulation of DNA synthesis in a biphasic response depending on the particular concentration of compactin used. The maximum enhanced rates of cellular DNA synthesis were observed with lower compactin concentrations (5 x 10(-7) mol/L) than were required for maximum inhibition of DNA synthesis (10(-5) mol/L). Leukemia cells displaying a stimulated response to compactin had a significantly lower baseline DNA synthetic rate than did cells that showed an inhibitory response of DNA synthesis to compactin. There was no correlation between these cells' varying DNA synthetic response to compactin and measures of baseline HMG CoA reductase activity or acetate conversion to cholesterol. Whereas the observation of cellular DNA synthesis stimulation by HMG CoA reductase inhibition has not been observed in other mammalian cells and seems paradoxical, explanations may emerge in light of our growing knowledge concerning the importance of isoprenylation for the function of certain cell regulatory proteins.

scholarly journals 3-Hydroxypropionyl-Coenzyme A Dehydratase and Acryloyl-Coenzyme A Reductase, Enzymes of the Autotrophic 3-Hydroxypropionate/4-Hydroxybutyrate Cycle in the Sulfolobales

2009 ◽  
Vol 191 (14) ◽  
pp. 4572-4581 ◽  
Author(s):  
Robin Teufel ◽  
Johannes W. Kung ◽  
Daniel Kockelkorn ◽  
Birgit E. Alber ◽  
Georg Fuchs
Keyword(s):  
Alcohol Dehydrogenase ◽  
Carbon Fixation ◽  
Coenzyme A ◽  
Chloroflexus Aurantiacus ◽  
Reaction Sequence ◽  
Acetyl Coenzyme A ◽  
Sulfolobus Tokodaii ◽  
Metallosphaera Sedula ◽  
Acetyl Coenzyme ◽  
Coa Reductase

ABSTRACT A 3-hydroxypropionate/4-hydroxybutyrate cycle operates in autotrophic CO2 fixation in various Crenarchaea, as studied in some detail in Metallosphaera sedula. This cycle and the autotrophic 3-hydroxypropionate cycle in Chloroflexus aurantiacus have in common the conversion of acetyl-coenzyme A (CoA) and two bicarbonates via 3-hydroxypropionate to succinyl-CoA. Both cycles require the reductive conversion of 3-hydroxypropionate to propionyl-CoA. In M. sedula the reaction sequence is catalyzed by three enzymes. The first enzyme, 3-hydroxypropionyl-CoA synthetase, catalyzes the CoA- and MgATP-dependent formation of 3-hydroxypropionyl-CoA. The next two enzymes were purified from M. sedula or Sulfolobus tokodaii and studied. 3-Hydroxypropionyl-CoA dehydratase, a member of the enoyl-CoA hydratase family, eliminates water from 3-hydroxypropionyl-CoA to form acryloyl-CoA. Acryloyl-CoA reductase, a member of the zinc-containing alcohol dehydrogenase family, reduces acryloyl-CoA with NADPH to propionyl-CoA. Genes highly similar to the Metallosphaera CoA synthetase, dehydratase, and reductase genes were found in autotrophic members of the Sulfolobales. The encoded enzymes are only distantly related to the respective three enzyme domains of propionyl-CoA synthase from C. aurantiacus, where this trifunctional enzyme catalyzes all three reactions. This indicates that the autotrophic carbon fixation cycles in Chloroflexus and in the Sulfolobales evolved independently and that different genes/enzymes have been recruited in the two lineages that catalyze the same kinds of reactions.

scholarly journals Activity of 3-hydroxy-3-methylglutaryl-coenzyme A reductase in brains of adult and 7-day-old rats

1976 ◽  
Vol 154 (2) ◽  
pp. 559-560 ◽  
Author(s):  
M M. Sudjic ◽  
R Booth
Keyword(s):  
Rat Brain ◽  
Coenzyme A ◽  
Reductase Activity ◽  
Cholesterol Biosynthesis ◽  
Adult Brain ◽  
Adult Rat ◽  
Adult Rat Brain ◽  
Old Rats ◽  
Coa Reductase ◽  
Coenzyme A Reductase

Rat brain contains 3-hydroxy-3-methylglutaryl-CoA reductase activity, but this enzyme is far more active in 7-day-old brain than in adult brain. This difference may partly explain why cholesterol biosynthesis is more rapid in growing than in adult rat brain.

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