scholarly journals Glucose dehydrogenase from the thermoacidophilic archaebacterium Sulfolobus solfataricus

1986 ◽  
Vol 239 (3) ◽  
pp. 517-522 ◽  
Author(s):  
P Giardina ◽  
M G de Biasi ◽  
M de Rosa ◽  
A Gambacorta ◽  
V Buonocore
Keyword(s):  
Oxidation Rate ◽  
Glucose Dehydrogenase ◽  
Sulfolobus Solfataricus ◽  
Maximal Activity ◽  
Equatorial Orientation ◽  
Guanidinium Chloride ◽  
Cell Extracts ◽  
Hydroxy Groups ◽  
Acid Substrate ◽  
Chaotropic Agents

Glucose dehydrogenase has been purified to homogeneity from cell extracts of the extreme thermoacidophilic archaebacterium Sulfolobus solfataricus. The enzyme utilizes both NAD+ and NADP+ as coenzyme and catalyses the oxidation of several monosaccharides to the corresponding glyconic acid. Substrate specificity and oxidation rate depend on the coenzyme present; when NAD+ is used, the enzyme binds and oxidizes specifically sugars presenting equatorial orientation of hydroxy groups at C-2, C-3 and C-4. The Mr of the native enzyme is 124,000 and decreases to about 60,000 in the presence of 6 M-guanidinium chloride and to about 30,000 in the presence of 5% (w/v) SDS. The enzyme shows maximal activity at pH 9, 77 degrees C and 20 mM-Mg2+, -Mn2+ or -Ca2+ and is fairly stable in the presence of chaotropic agents and water-miscible organic solvents such as methanol or acetone.

scholarly journals A Redox-Neutral, Two-Enzyme Cascade for the Production of Malate and Gluconate from Pyruvate and Glucose

2021 ◽  
Vol 11 (11) ◽  
pp. 4877
Author(s):  
Ravneet Mandair ◽  
Pinar Karagoz ◽  
Roslyn M. Bill
Keyword(s):  
Malate Dehydrogenase ◽  
Closed System ◽  
Glucose Dehydrogenase ◽  
Sulfolobus Solfataricus ◽  
Cofactor Regeneration ◽  
Triple Mutant ◽  
Thermococcus Kodakarensis ◽  
Platform Chemicals ◽  
Enzyme Cascade

A triple mutant of NADP(H)-dependent malate dehydrogenase from thermotolerant Thermococcus kodakarensis has an altered cofactor preference for NAD+, as well as improved malate production compared to wildtype malate dehydrogenase. By combining mutant malate dehydrogenase with glucose dehydrogenase from Sulfolobus solfataricus and NAD+/NADH in a closed reaction environment, gluconate and malate could be produced from pyruvate and glucose. After 3 h, the yield of malate was 15.96 mM. These data demonstrate the feasibility of a closed system capable of cofactor regeneration in the production of platform chemicals.

scholarly journals Accumulation of α-Keto Acids as Essential Components in Cyanide Assimilation by Pseudomonas fluorescens NCIMB 11764

1998 ◽  
Vol 64 (11) ◽  
pp. 4452-4459 ◽  
Author(s):  
Daniel A. Kunz ◽  
Jui-Lin Chen ◽  
Guangliang Pan
Keyword(s):  
Pseudomonas Fluorescens ◽  
Culture Fluid ◽  
Maximal Activity ◽  
Resonance Spectroscopy ◽  
Keto Acid ◽  
Growth Substrate ◽  
Reaction Products ◽  
Cell Extracts ◽  
Keto Acids ◽  
Essential Components

ABSTRACT Pyruvate (Pyr) and α-ketoglutarate (αKg) accumulated when cells of Pseudomonas fluorescens NCIMB 11764 were cultivated on growth-limiting amounts of ammonia or cyanide and were shown to be responsible for the nonenzymatic removal of cyanide from culture fluids as previously reported (J.-L. Chen and D. A. Kunz, FEMS Microbiol. Lett. 156:61–67, 1997). The accumulation of keto acids in the medium paralleled the increase in cyanide-removing activity, with maximal activity (760 μmol of cyanide removed min−1 ml of culture fluid−1) being recovered after 72 h of cultivation, at which time the keto acid concentration was 23 mM. The reaction products that formed between the biologically formed keto acids and cyanide were unambiguously identified as the corresponding cyanohydrins by 13C nuclear magnetic resonance spectroscopy. Both the Pyr and α-Kg cyanohydrins were further metabolized by cell extracts and served also as nitrogenous growth substrates. Radiotracer experiments showed that CO2 (and NH3) were formed as enzymatic conversion products, with the keto acid being regenerated as a coproduct. Evidence that the enzyme responsible for cyanohydrin conversion is cyanide oxygenase, which was shown previously to be required for cyanide utilization, is based on results showing that (i) conversion occurred only when extracts were induced for the enzyme, (ii) conversion was oxygen and reduced-pyridine nucleotide dependent, and (iii) a mutant strain defective in the enzyme was unable to grow when it was provided with the cyanohydrins as a growth substrate. Pyr and αKg were further shown to protect cells from cyanide poisoning, and excretion of the two was directly linked to utilization of cyanide as a growth substrate. The results provide the basis for a new mechanism of cyanide detoxification and assimilation in which keto acids play an essential role.

scholarly journals Optimization of an In Vitro Transcription/Translation System Based on Sulfolobus solfataricus Cell Lysate

Archaea ◽  
2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Giada Lo Gullo ◽  
Rosanna Mattossovich ◽  
Giuseppe Perugino ◽  
Anna La Teana ◽  
Paola Londei ◽  
...  
Keyword(s):  
High Efficiency ◽  
Specific Activity ◽  
Expression System ◽  
Sulfolobus Solfataricus ◽  
Essential Element ◽  
23S Rrna ◽  
Translation System ◽  
Cell Lysate ◽  
Cell Extracts

A system is described which permits the efficient synthesis of proteins in vitro at high temperature. It is based on the use of an unfractionated cell lysate (S30) from Sulfolobus solfataricus previously well characterized in our laboratory for translation of pretranscribed mRNAs, and now adapted to perform coupled transcription and translation. The essential element in this expression system is a strong promoter derived from the S. solfataricus 16S/23S rRNA-encoding gene, from which specific mRNAs may be transcribed with high efficiency. The synthesis of two different proteins is reported, including the S. solfataricus DNA-alkylguanine-DNA-alkyl-transferase protein (SsOGT), which is shown to be successfully labeled with appropriate fluorescent substrates and visualized in cell extracts. The simplicity of the experimental procedure and specific activity of the proteins offer a number of possibilities for the study of structure-function relationships of proteins.

scholarly journals Purification and Characterization ofStreptomyces griseus CatecholO-Methyltransferase

2000 ◽  
Vol 66 (11) ◽  
pp. 4877-4882 ◽  
Author(s):  
Kajari Dhar ◽  
John P. N. Rosazza
Keyword(s):  
Enzyme Purification ◽  
Deae Cellulose ◽  
Streptomyces Griseus ◽  
Maximal Activity ◽  
Competitive Inhibitor ◽  
Amino Acid Sequences ◽  
Assay Method ◽  
Purification And Characterization ◽  
Denatured Protein ◽  
Cell Extracts

ABSTRACT A soluble (100,000 × g supernatant) methyltransferase catalyzing the transfer of the methyl group ofS-adenosyl-l-methionine to catechols was present in cell extracts of Streptomyces griseus. A simple, general, and rapid catechol-based assay method was devised for enzyme purification and characterization. The enzyme was purified 141-fold by precipitation with ammonium sulfate and successive chromatography over columns of DEAE-cellulose, DEAE-Sepharose, and Sephacryl S-200. The purified cytoplasmic enzyme required 10 mM magnesium for maximal activity and was catalytically optimal at pH 7.5 and 35°C. The methyltransferase had an apparent molecular mass of 36 kDa for both the native and denatured protein, with a pI of 4.4. Novel N-terminal and internal amino acid sequences were determined as DFVLDNEGNPLENNGGYXYI and RPDFXLEPPYTGPXKARIIRYFY, respectively. For this enzyme, theKm for 6,7-dihydroxycoumarin was 500 ± 21.5 μM, and that for S-adenosyl-l-methionine was 600 ± 32.5 μM. Catechol, caffeic acid, and 4-nitrocatechol were methyltransferase substrates. Homocysteine was a competitive inhibitor of S-adenosyl-l-methionine, with aKi of 224 ± 20.6 μM. Sinefungin andS-adenosylhomocysteine inhibited methylation, and the enzyme was inactivated by Hg2+,p-chloromercuribenzoic acid, andN-ethylmaleimide.

scholarly journals Novel Pathway for Alcoholic Fermentation of δ-Gluconolactone in the Yeast Saccharomyces bulderi

2002 ◽  
Vol 184 (3) ◽  
pp. 672-678 ◽  
Author(s):  
Johannes P. van Dijken ◽  
Arjen van Tuijl ◽  
Marijke A. H. Luttik ◽  
Wouter J. Middelhoven ◽  
Jack T. Pronk
Keyword(s):  
Pentose Phosphate Pathway ◽  
Alcoholic Fermentation ◽  
Kinase Activity ◽  
Glucose Dehydrogenase ◽  
Sole Source ◽  
Pentose Phosphate ◽  
Anaerobic Growth ◽  
Ph Values ◽  
Cell Extracts ◽  
Dehydrogenase Reaction

ABSTRACT Under anaerobic conditions, the yeast Saccharomyces bulderi rapidly ferments δ-gluconolactone to ethanol and carbon dioxide. We propose that a novel pathway for δ-gluconolactone fermentation operates in this yeast. In this pathway, δ-gluconolactone is first reduced to glucose via an NADPH-dependent glucose dehydrogenase (EC 1.1.1.47). After phosphorylation, half of the glucose is metabolized via the pentose phosphate pathway, yielding the NADPH required for the glucose-dehydrogenase reaction. The remaining half of the glucose is dissimilated via glycolysis. Involvement of this novel pathway in δ-gluconolactone fermentation in S. bulderi is supported by several experimental observations. (i) Fermentation of δ-gluconolactone and gluconate occurred only at low pH values, at which a substantial fraction of the substrate is present as δ-gluconolactone. Unlike gluconate, the latter compound is a substrate for glucose dehydrogenase. (ii) High activities of an NADP+-dependent glucose dehydrogenase were detected in cell extracts of anaerobic, δ-gluconolactone-grown cultures, but activity of this enzyme was not detected in glucose-grown cells. Gluconate kinase activity in cell extracts was negligible. (iii) During anaerobic growth on δ-gluconolactone, CO2 production exceeded ethanol production by 35%, indicating that pyruvate decarboxylation was not the sole source of CO2. (iv) Levels of the pentose phosphate pathway enzymes were 10-fold higher in δ-gluconolactone-grown anaerobic cultures than in glucose-grown cultures, consistent with the proposed involvement of this pathway as a primary dissimilatory route in δ-gluconolactone metabolism.

scholarly journals The pH optimum of native uracil-DNA glycosylase of Archaeoglobus fulgidus compared to recombinant enzyme indicates adaption to cytosolic pH.

2014 ◽  
Vol 61 (2) ◽  
Author(s):  
Ingeborg Knævelsrud ◽  
Sabina Kazazic ◽  
Nils-Kåre Birkeland ◽  
Svein Bjelland
Keyword(s):  
Optimal Growth ◽  
Maximal Activity ◽  
Recombinant Enzyme ◽  
Dna Glycosylase ◽  
Archaeoglobus Fulgidus ◽  
Ph Optimum ◽  
Cytosolic Ph ◽  
Uracil Dna Glycosylase ◽  
Cell Extracts ◽  
Covalent Modifications

Uracil-DNA glycosylase of Archaeoglobus fulgidus (Afung) in cell extracts exhibited maximal activity around pH 6.2 as compared to pH 4.8 for the purified recombinant enzyme expressed in Escherichia coli. Native Afung thus seems to be adapted to the intracellular pH of A. fulgidus, determined to be 7.0±0.1. Both recombinant and native Afung exhibited a broad temperature optimum for activity around 80°C, reflecting the A. fulgidus optimal growth temperature of 83°C. Adaption to the neutral conditions in the A. fulgidus cytoplasm might be due to covalent modifications or accessory factors, or due to a different folding when expressed in the native host.

scholarly journals In Vitro Processing of the 16S rRNA of the Thermophilic Archaeon Sulfolobus solfataricus

2001 ◽  
Vol 183 (13) ◽  
pp. 3866-3874 ◽  
Author(s):  
Andrea Ciammaruconi ◽  
Paola Londei
Keyword(s):  
16S Rrna ◽  
Sulfolobus Solfataricus ◽  
Conserved Sequence ◽  
Processing Enzymes ◽  
Cell Extracts ◽  
In Vitro Processing ◽  
16S Rna ◽  
Thermophilic Archaeon ◽  
Rna Maturation

ABSTRACT In this paper we have analyzed the processing in vitro of the 16S rRNA of the thermophilic archaeon Sulfolobus solfataricus, using pre-rRNA substrates transcribed in vitro and different protein preparations as the source of processing enzymes. We show that the 5′ external transcribed spacer of the S. solfataricus pre-rRNA transcript contains a target site for a specific endonuclease, which recognizes a conserved sequence also existing in the early A0 and 0 processing sites of Saccharomyces cerevisiae and vertebrates. This site is present in other members of the kingdomCrenarchaeota but apparently not in theEuryarchaeota. Furthermore, S. solfataricuspre-16S RNA is processed within the double-helical stem formed by the inverted repeats flanking the 16S RNA sequence, in correspondence with a bulge-helix-bulge motif. The endonuclease responsible for this cleavage is present in both the Crenarchaeota and theEuryarchaeota. The processing pattern remained the same when the substrate was a 30S ribonucleoprotein particle instead of the naked RNA. Maturation of either the 5′ or the 3′ end of the 16S RNA molecule was not observed, suggesting either that maturation requires conditions not easily reproducible in vitro or that the responsible endonucleases are scarcely represented in cell extracts.

scholarly journals Mercury Inactivates Transcription and the Generalized Transcription Factor TFB in the Archaeon Sulfolobus solfataricus

2004 ◽  
Vol 48 (6) ◽  
pp. 1993-1999 ◽  
Author(s):  
Vidula Dixit ◽  
Elisabetta Bini ◽  
Melissa Drozda ◽  
Paul Blum
Keyword(s):  
Transcription Factor ◽  
Mercuric Chloride ◽  
Sulfolobus Solfataricus ◽  
In Vitro Transcription ◽  
Mercury Toxicity ◽  
Transcription Activity ◽  
Treated Cell ◽  
Mercuric Ion ◽  
Cell Extracts

ABSTRACT Mercury has a long history as an antimicrobial agent effective against eukaryotic and prokaryotic organisms. Despite its prolonged use, the basis for mercury toxicity in prokaryotes is not well understood. Archaea, like bacteria, are prokaryotes but they use a simplified version of the eukaryotic transcription apparatus. This study examined the mechanism of mercury toxicity to the archaeal prokaryote Sulfolobus solfataricus. In vivo challenge with mercuric chloride instantaneously blocked cell division, eliciting a cytostatic response at submicromolar concentrations and a cytocidal response at micromolar concentrations. The cytostatic response was accompanied by a 70% reduction in bulk RNA synthesis and elevated rates of degradation of several transcripts, including tfb-1, tfb-2, and lacS. Whole-cell extracts prepared from mercuric chloride-treated cells or from cell extracts treated in vitro failed to support in vitro transcription of 16S rRNAp and lacSp promoters. Extract-mixing experiments with treated and untreated extracts excluded the occurrence of negative-acting factors in the mercury-treated cell extracts. Addition of transcription factor B (TFB), a general transcription factor homolog of eukaryotic TFIIB, to mercury-treated cell extracts restored >50% of in vitro transcription activity. Consistent with this finding, mercuric ion treatment of TFB in vitro inactivated its ability to restore the in vitro transcription activity of TFB-immunodepleted cell extracts. These findings indicate that the toxicity of mercuric ion in S. solfataricus is in part the consequence of transcription inhibition due to TFB-1 inactivation.

scholarly journals Maltose Metabolism in the Hyperthermophilic Archaeon Thermococcus litoralis: Purification and Characterization of Key Enzymes

1999 ◽  
Vol 181 (11) ◽  
pp. 3358-3367 ◽  
Author(s):  
Karina B. Xavier ◽  
Ralf Peist ◽  
Marina Kossmann ◽  
Winfried Boos ◽  
Helena Santos
Keyword(s):  
Specific Activity ◽  
Pyrococcus Furiosus ◽  
Maximal Activity ◽  
Consensus Binding Site ◽  
Calculated Molecular Mass ◽  
Thermococcus Litoralis ◽  
Hyperthermophilic Archaeon ◽  
Key Enzymes ◽  
Maltose Metabolism ◽  
Cell Extracts

ABSTRACT Maltose metabolism was investigated in the hyperthermophilic archaeon Thermococcus litoralis. Maltose was degraded by the concerted action of 4-α-glucanotransferase and maltodextrin phosphorylase (MalP). The first enzyme produced glucose and a series of maltodextrins that could be acted upon by MalP when the chain length of glucose residues was equal or higher than four, to produce glucose-1-phosphate. Phosphoglucomutase activity was also detected inT. litoralis cell extracts. Glucose derived from the action of 4-α-glucanotransferase was subsequently metabolized via an Embden-Meyerhof pathway. The closely related organism Pyrococcus furiosus used a different metabolic strategy in which maltose was cleaved primarily by the action of an α-glucosidase, ap-nitrophenyl-α-d-glucopyranoside (PNPG)-hydrolyzing enzyme, producing glucose from maltose. A PNPG-hydrolyzing activity was also detected in T. litoralis, but maltose was not a substrate for this enzyme. The two key enzymes in the pathway for maltose catabolism in T. litoralis were purified to homogeneity and characterized; they were constitutively synthesized, although phosphorylase expression was twofold induced by maltodextrins or maltose. The gene encoding MalP was obtained by complementation in Escherichia coli and sequenced (calculated molecular mass, 96,622 Da). The enzyme purified from the organism had a specific activity for maltoheptaose, at the temperature for maximal activity (98°C), of 66 U/mg. AKm of 0.46 mM was determined with heptaose as the substrate at 60°C. The deduced amino acid sequence had a high degree of identity with that of the putative enzyme from the hyperthermophilic archaeon Pyrococcus horikoshii OT3 (66%) and with sequences of the enzymes from the hyperthermophilic bacteriumThermotoga maritima (60%) and Mycobacterium tuberculosis (31%) but not with that of the enzyme from E. coli (13%). The consensus binding site for pyridoxal 5′-phosphate is conserved in the T. litoralis enzyme.

scholarly journals Purification and characterization of glucose dehydrogenase from the thermoacidophilic archaebacterium Thermoplasma acidophilum

1989 ◽  
Vol 261 (3) ◽  
pp. 973-977 ◽  
Author(s):  
L D Smith ◽  
N Budgen ◽  
S J Bungard ◽  
M J Danson ◽  
D W Hough
Keyword(s):  
Amino Acid ◽  
Polypeptide Chain ◽  
Glucose Dehydrogenase ◽  
Sulfolobus Solfataricus ◽  
Purification And Characterization ◽  
Terminal Amino Acid ◽  
Thermoplasma Acidophilum ◽  
Catalytically Active ◽  
Terminal Amino

Glucose dehydrogenase was purified to homogeneity from the thermoacidophilic archaebacterium Thermoplasma acidophilum. The enzyme is a tetramer of polypeptide chain Mr 38,000 +/- 3000, it is catalytically active with both NAD+ and NADP+ cofactors, and it is thermostable and remarkably resistant to a variety of organic solvents. The amino acid composition was determined and compared with those of the glucose dehydrogenases from the archaebacterium Sulfolobus solfataricus and the eubacteria Bacillus subtilis and Bacillus megaterium. The N-terminal amino acid sequence of the Thermoplasma acidophilum enzyme was determined to be: (S/T)-E-Q-K-A-I-V-T-D-A-P-K-G-G-V-K-Y-T-T-I-D-M-P-E.

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