Hydrogen production from pyruvate by enzymes purified from the hyperthermophilic archaeon, Pyrococcus furiosus: A key role for NADPH

Ma, K

doi:10.1016/0378-1097(94)00330-0

Cited by 16 publications

(21 citation statements)

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“…23 In aerobic bacteria and eukarya, the reaction is catalyzed by the pyruvate dehydrogenase multienzyme complex with NAD as an electron acceptor. The ferredoxin reduced by POR is reoxidized by sulfide dehydrogenase24, 25 and hydrogenase,26, 27 which are respectively coupled to S° reduction and H 2 production. ACS couples acetate formation from acetyl‐CoA with the phospholylation of ADP via the mechanism of substrate‐level phospholylation.…”

Section: Introductionmentioning

confidence: 99%

Unique sugar metabolism and novel enzymes of hyperthermophilic archaea

Sakuraba

Goda

Ohshima

2004

The Chemical Record

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Hyperthermophiles are a group of microorganisms that have their optimum growth temperature above 80 degrees C. More than 60 species of the hyperthermophiles have been isolated from marine and continental volcanic environments. Most hyperthermophiles belong to Archaea, the third domain of life, and are considered to be the most ancient of all extant life forms. Recent studies have revealed the presence of unusual sugar metabolic processes in hyperthermophilic archaea, for example, a modified Embden-Meyerhof pathway, that has so far not been observed in bacteria and eucarya. Several novel enzymes, such as ADP-dependent glucokinase, ADP-dependent phosphofructokinase, glyceraldehyde-3-phosphate ferredoxin oxidoreductase, phosphoenolpyruvate synthase, pyruvate : ferredoxin oxidoreductase, and ADP-forming acetyl-CoA synthetase, have been found to be involved in a modified Embden-Meyerhof pathway of the hyperthermophilic archaeon Pyrococcus furiosus. In addition, a unique mode of ATP regeneration has been postulated to exist in the pathway of P. furiosus. The metabolic design observed in this microorganism might reflect the situation at an early stage of evolution.

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Section: Introductionmentioning

confidence: 99%

Unique sugar metabolism and novel enzymes of hyperthermophilic archaea

Sakuraba

Goda

Ohshima

2004

The Chemical Record

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“…In plants and cyanobacteria, a similar activity, ferredoxin:NADP reductase, is bound to membranes by an anchor protein or an N-terminal polypeptide extension of the ferredoxin:NADP reductase (Forti et al 1983;Schluchter and Bryant 1992). Ferredoxin:NADP oxidoreductase from Pyrococcus furiosus is a soluble enzyme with sulfide dehydrogenase activity (Ma et al 1994). Although T. neapolitana also has a similar sulfur reductase activity, it is an enzyme distinct from the NMOR (Table 1) (Childers and Noll 1995b).…”

Section: Resultsmentioning

confidence: 97%

Membrane-associated redox activities in Thermotoga neapolitana

Käslin

Childers

Noll

1998

Archives of Microbiology

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Elemental sulfur reduction by the hyperthermophilic bacterium Thermotoga neapolitana provides an alternative to hydrogen evolution during fermentation. Electrons are transferred from reduced cofactors (ferredoxin and NADH) to sulfur by a series of unknown steps. One enzyme that may be involved is an NADH:methyl viologen oxidoreductase (NMOR), an activity that in other fermenting organisms is associated with NADH:ferredoxin oxidoreductase. We found that 83% of NMOR activity was contained in the pellet fraction of cell extracts subjected to ultracentrifugation. This pellet fraction, presumably containing cell membranes, was required for electron transfer to NAD+ from ferredoxin-dependent pyruvate oxidation. However, the NMOR activity in this fraction used neither Thermotoga nor clostridial ferredoxins as substrates. NMOR activity was also detected in aerobically prepared vesicles. By comparison with ATPase activities, NMOR was found primarily on the cytoplasmic face of these vesicles. During these studies, an extracytoplasmic hydrogenase activity was discovered. In contrast to the soluble hydrogenase, this hydrogenase activity was completely inhibited when intact cells were treated with cupric chloride and was present on the extracytoplasmic face of vescides. In contrast to a soluble hydrogenase reported in Thermotoga maritima, this activity was air-stable and was inhibited by low concentrations of nitrite.

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“…The rate and yield of hydrogen production from sucrose in the absence of glucose isomerase were studied as a function of pH and sucrose concentration. The pH optima of the enzymes in the system range from pH 5.0 for invertase (12) to pH 8.0 for hydrogenase (5), while GDH has a pH optimum of 7.0 (6). At pH 7.5 the concentration of invertase used completely hydrolyzed up to 100 mg/mL sucrose (0.29 M).…”

Section: Resultsmentioning

confidence: 99%

“…Glucose dehydrogenase (GDH) from Thermoplasma acidophilum catalyzes the oxidation of glucose to glucono‐δ‐lactone, which is hydrolyzed to gluconic acid (4), and the cofactor for this reaction is either NAD + or NADP + which is reduced. Hydrogenase from Pyrococcus furiosus uses NADPH as an electron donor (5), resulting in molecular hydrogen and regeneration and recycle of NADP + . This pathway could then produce a maximum stoichiometric yield of 1 mol of hydrogen/mol of sucrose.…”

Section: Introductionmentioning

confidence: 99%

Enzymatic Conversion of Sucrose to Hydrogen

Woodward

Orr

1998

Biotechnol. Prog.

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The enzymatic conversion of sugars to hydrogen could be a promising method for alternative fuel production. Maple tree sap is a source of environmental sugar (e.g., sucrose) that has the potential to be converted into hydrogen using the enzymes invertase, glucose dehydrogenase (GDH), hydrogenase, and glucose isomerase (GI) and the cofactor NADP+/NADPH. The kinetics of hydrogen production have been studied, and optimal conditions for hydrogen production are described. At low initial sucrose concentrations, in the absence of glucose isomerase, stoichiometric yields of 1 mol of H2/mol of sucrose were achieved. At higher sucrose concentrations, the yield of hydrogen declined so that at an initial sucrose concentration of 292 mM only 7% yield of hydrogen was obtained. The reason for this low yield was studied and shown not to be caused by enzyme inactivation or a pH drop during the reaction but due to an instability of the cofactor NADP+. Although gluconic acid inhibited both NADPH production and oxidation by GDH and hydrogenase, respectively, it was not the major cause of NADP+ instability. Fructose was also shown to be converted to hydrogen if GI was present in the reaction mixture. Also, by starting with sucrose, 1. 34 mol of H2/mol of sucrose was obtained if GI was present in the reaction mixture.

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Hydrogen production from pyruvate by enzymes purified from the hyperthermophilic archaeon, Pyrococcus furiosus: A key role for NADPH

Cited by 16 publications

References 0 publications

Unique sugar metabolism and novel enzymes of hyperthermophilic archaea

Unique sugar metabolism and novel enzymes of hyperthermophilic archaea

Membrane-associated redox activities in Thermotoga neapolitana

Enzymatic Conversion of Sucrose to Hydrogen

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