Characterization of Biomimetic Cofactors According to Stability, Redox Potentials, and Enzymatic Conversion by NADH Oxidase from Lactobacillus pentosus

ChemBioChem ◽  
2017 ◽  
Vol 18 (19) ◽  
pp. 1944-1949 ◽  
Author(s):  
Claudia Nowak ◽  
André Pick ◽  
Lénárd-István Csepei ◽  
Volker Sieber
Keyword(s):  
Nadh Oxidase ◽  
Enzymatic Conversion ◽  
Redox Potentials ◽  
Lactobacillus Pentosus

scholarly journals A water-forming NADH oxidase from Lactobacillus pentosus suitable for the regeneration of synthetic biomimetic cofactors

2015 ◽  
Vol 6 ◽  
Author(s):  
Claudia Nowak ◽  
Barbara Beer ◽  
André Pick ◽  
Teresa Roth ◽  
Petra Lommes ◽  
...  
Keyword(s):  
Nadh Oxidase ◽  
Lactobacillus Pentosus

scholarly journals Structural and Kinetic Characterization of Hyperthermophilic NADH-Dependent Persulfide Reductase from Archaeoglobus fulgidus

Archaea ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Sherwin Shabdar ◽  
Bukuru Anaclet ◽  
Ana Garcia Castineiras ◽  
Neyissa Desir ◽  
Nicholas Choe ◽  
...  
Keyword(s):  
Nadh Oxidase ◽  
Reductase Activity ◽  
Sulfur Metabolism ◽  
Archaeoglobus Fulgidus ◽  
Bacterial Enzymes ◽  
Detectable Activity ◽  
Metabolic Role ◽  
Nadh Oxidase Activity

NADH-dependent persulfide reductase (Npsr) has been proposed to facilitate dissimilatory sulfur respiration by reducing persulfide or sulfane sulfur-containing substrates to H2S. The presence of this gene in the sulfate and thiosulfate-reducing Archaeoglobus fulgidus DSM 4304 and other hyperthermophilic Archaeoglobales appears anomalous, as A. fulgidus is unable to respire S0 and grow in the presence of elemental sulfur. To assess the role of Npsr in the sulfur metabolism of A. fulgidus DSM 4304, the Npsr from A. fulgidus was characterized. AfNpsr is specific for persulfide and polysulfide as substrates in the oxidative half-reaction, exhibiting k cat / K m on the order of 104 M-1 s-1, which is similar to the kinetic parameters observed for hyperthermophilic CoA persulfide reductases. In contrast to the bacterial Npsr, AfNpsr exhibits low disulfide reductase activity with DTNB; however, similar to the bacterial enzymes, it does not show detectable activity with CoA-disulfide, oxidized glutathione, or cystine. The 3.1 Å X-ray structure of AfNpsr reveals access to the tightly bound catalytic CoA, and the active site Cys 42 is restricted by a flexible loop (residues 60-66) that is not seen in the bacterial homologs from Shewanella loihica PV-4 and Bacillus anthracis. Unlike the bacterial enzymes, AfNpsr exhibits NADH oxidase activity and also shows no detectable activity with NADPH. Models suggest steric and electrostatic repulsions of the NADPH 2 ′ -phosphate account for the strong preference for NADH. The presence of Npsr in the nonsulfur-reducing A. fulgidus suggests that the enzyme may offer some protection against S0 or serve in another metabolic role that has yet to be identified.

Tuning the Electrochemical and Photophysical Properties of Osmium-Based Photoredox Catalysts

Synlett ◽  
2022 ◽  
Author(s):  
Eva Bednářová ◽  
Logan R. Beck ◽  
Tomislav Rovis ◽  
Samantha L. Goldschmid ◽  
Katherine Xie ◽  
...  
Keyword(s):  
Ground State ◽  
Emission Spectroscopy ◽  
Near Infrared ◽  
Photophysical Properties ◽  
Low Energy ◽  
Redox Potentials ◽  
Nir Light ◽  
Osmium Complexes ◽  
Absorption And Emission Spectroscopy

AbstractThe use of low-energy deep-red (DR) and near-infrared (NIR) light to excite chromophores enables catalysis to ensue across barriers such as materials and tissues. Herein, we report the detailed photophysical characterization of a library of OsII polypyridyl photosensitizers that absorb low-energy light. By tuning ligand scaffold and electron density, we access a range of synthetically useful excited state energies and redox potentials.1 Introduction1.1 Scope1.2 Measuring Ground-State Redox Potentials1.3 Measuring Photophysical Properties1.4 Synthesis of Osmium Complexes2 Properties of Osmium Complexes2.1 Redox Potentials of Os(L)2-Type Complexes2.2 Redox Potentials of Os(L)3-Type Complexes2.3 UV/Vis Absorption and Emission Spectroscopy3 Conclusions

Metallkomplexe mit Tetrapyrrol-Liganden, XIX [1]. Synthese und elektrochemische Charakterisierung der Kohlenmonosulfid-Metalloctaethylporphyrine mit Eisen(II) oder Osmium(II) im Zentrum. Ein Beitrag zur "Bathochromie-Regel" / Metal Complexes with Tetrapyrrole Ligands, XIX [1]. Synthesis and Electrochemical Characterization of Thiocarbonyl Metallooctaethylporphyrins with Iron(II) or Osmium(II) in the Center. A Contribution to the "Rule of Bathochromism"

1978 ◽  
Vol 33 (12) ◽  
pp. 1371-1380 ◽  
Author(s):  
Johann W. Buchler ◽  
Wolfgang Kokisch ◽  
Paul D. Smith ◽  
Bernhard Tonn
Keyword(s):  
Metal Complexes ◽  
Linear Correlation ◽  
Optical Spectrum ◽  
Spectroscopic Characterization ◽  
Electrochemical Characterization ◽  
Redox Potentials ◽  
Acceptor Capacity ◽  
Α Band

The preparation and spectroscopic characterization of thiocarbonyl metalloporphyrins M(OEP)CS(L') (e.g. 2e: M = Fe, L' = Py, 1e: M = Os, L' = Py** are described. Especially noteworthy is the existence of a pentacoordinate, diamagnetic, air-stable heme Fe(OEP)CS (2f: M = Fe, no L′). A linear correlation of the α-band frequencies (expressed as ϋa) in the optical spectrum and the metal(II/III) redox potentials (E1/2) taken from cyclic voltam­metry experiments suggests (Abb. 3) that in complexes of the type M(OEP)LL' (1,2) λa is bathochromically shifted as the π-acceptor capacity of L increases (“Rule of Bathochromism”). The strong π-acceptor capacity of carbon monosulphide renders the attack of dioxygen to the thiocarbonyl heme unfavourable; O2 and CS seem to be comparable in their π-acceptor strength.

Optimization of extraction conditions and fatty acid characterization of Lactobacillus pentosus cell-bound biosurfactant/bioemulsifier

2014 ◽  
Vol 95 (2) ◽  
pp. 313-320 ◽  
Author(s):  
Xanel Vecino ◽  
Letricia Barbosa-Pereira ◽  
Rosa Devesa-Rey ◽  
José M Cruz ◽  
Ana B Moldes
Keyword(s):  
Fatty Acid ◽  
Lactobacillus Pentosus

scholarly journals Characterization of an Exceedingly Active NADH Oxidase from the Anaerobic Hyperthermophilic Bacterium Thermotoga maritima

2007 ◽  
Vol 189 (8) ◽  
pp. 3312-3317 ◽  
Author(s):  
Xianqin Yang ◽  
Kesen Ma
Keyword(s):  
Nadh Oxidase ◽  
Specific Activity ◽  
Ph Value ◽  
Thermotoga Maritima ◽  
Cell Extract ◽  
Hyperthermophilic Bacterium ◽  
Its Gene ◽  
Molecular Masses ◽  
New Type

ABSTRACT An NADH oxidase from the anaerobic hyperthermophilic bacterium Thermotoga maritima was purified. The enzyme was very active in catalyzing the reduction of oxygen to hydrogen peroxide with an optimal pH value of 7 at 80°C. The Vmax was 230 ± 14 μmol/min/mg (k cat/Km = 548,000 min−1 mM−1), and the Km values for NADH and oxygen were 42 ± 3 and 43 ± 4 μM, respectively. The NADH oxidase was a heterodimeric flavoprotein with two subunits with molecular masses of 54 kDa and 46 kDa. Its gene sequences were identified, and the enzyme might represent a new type of NADH oxidase in anaerobes. An NADH-dependent peroxidase with a specific activity of 0.1 U/mg was also present in the cell extract of T. maritima.

Purification and characterization of Sporolactobacillus inulinus NADH oxidase and its physiological role in aerobic metabolism of the bacterium

1997 ◽  
Vol 84 (1) ◽  
pp. 22-27 ◽  
Author(s):  
Yoshitaka Nishiyama ◽  
Vincent Massey ◽  
Yukiko Anzai ◽  
Toshihiro Watanabe ◽  
Tatsurou Miyaji ◽  
...  
Keyword(s):  
Nadh Oxidase ◽  
Physiological Role ◽  
Aerobic Metabolism ◽  
Purification And Characterization

Electrochemical and Spectroelectrochemical Characterization of Water-soluble, β-Pyrrolebrominated Cobalt Porphyrins

1998 ◽  
Vol 02 (05) ◽  
pp. 429-437 ◽  
Author(s):  
FRANCIS D'SOUZA ◽  
YI-YING HSIEH ◽  
G. R. DEVIPRASAD
Keyword(s):  
Water Soluble ◽  
Redox Couple ◽  
Redox Potentials ◽  
Complete Elimination ◽  
Porphyrin Derivatives ◽  
Cobalt Porphyrins ◽  
Bulk Electrolysis ◽  
Ph Conditions ◽  
Ph Dependent

The electrochemical and spectroelectrochemical characterization of two water-soluble porphyrins, namely the tetrachloro salt of cobalt(II) tetrakis-(N-methyl pyridyl)-β-octabromoporphyrin, [( Br 8 TMPyP ) Co II] Cl 4, and the tetrasodium salt of cobalt(II) tetrakis-(4-sulfonatophenyl)-β-octabromoporphyrin, Na 4[( Br 8 TPPS ) Co II], under different pH conditions is reported. The investigated porphyrins are highly non-planar and electron-deficient owing to the presence of eight bromides at the β-pyrrole positions and the four meso-aryl substituents. The redox potentials corresponding to the first oxidation and first reduction are shifted positively compared with the redox potentials of the respective unbrominated porphyrin derivatives. Spectroelectrochemical studies reveal the formation of a cobalt(III) complex during the first oxidation of both cobalt porphyrins. The first reduction of Br 8 TPPS ) Co II]4− results in a cobalt(I) complex, while involvement of the peripheral N-methyl pyridyl groups in the case of Br 8 TMPyP ) Co II]4+ is suggested. The peak potentials of the first oxidation corresponding to a Co II/ Co III redox couple of both investigated compounds are found to be pH-dependent. Debromination of the β-pyrrole bromo substituents of Br 8 TMPyP ) Co II]4+ at more negative potentials is observed. The UV-vis spectrum obtained after bulk electrolysis of Br 8 TMPyP ) Co II]4+ at −1.0 V vs Ag / AgCl followed by reoxidation at 0.2 V indicates complete elimination of the bromo substituents of the porphyrin periphery.

Spectroelectrochemical characterization of meso triaryl-substituted Mn(IV), Mn(III) and Mn(II) corroles. Effect of solvent and oxidation state on UV-visible spectra and redox potentials in nonaqueous media

2014 ◽  
Vol 18 (12) ◽  
pp. 1131-1144 ◽  
Author(s):  
Bingbing Gao ◽  
Zhongping Ou ◽  
Xueyan Chen ◽  
Shi Huang ◽  
Bihong Li ◽  
...  
Keyword(s):  
Anion Radical ◽  
Cation Radical ◽  
Oxidation Mechanism ◽  
Central Metal ◽  
Redox Potentials ◽  
Nonaqueous Media ◽  
Visible Spectra ◽  
Phenyl Rings ◽  
Uv Visible

Two series of substituted manganese triarylcorroles were synthesized and characterized as to their electrochemical and spectroelectrochemical properties in CH 2 Cl 2, CH 3 CN and pyridine. The investigated compounds are represented as ( YPh )3 CorMn III and ( YPh )3 CorMn IV Cl , where Cor is a trianion of the corrole and Y is a Cl , F , H or CH 3 para-substituent on the three phenyl rings of the macrocycle. Each neutral Mn(III) corrole exists as a four-coordinate complex in CH 2 Cl 2 and CH 3 CN and as a five-coordinate species in pyridine. ( YPh )3 CorMn III undergoes two oxidations to stepwise generate a Mn(IV) corrole and a Mn(IV) π-cation radical. It also undergoes one reduction to generate a Mn(II) corrole in CH 2 Cl 2 or CH 3 CN . In contrast, the reduction of ( YPh )3 CorMn III leads to a Mn(III) corrole π-anion radical in pyridine. One oxidation is observed for ( YPh )3 CorMn IV Cl in CH 2 Cl 2 and CH 3 CN to generate a Mn(IV) corrole π-cation radical while Mn(III) and Mn(II) corroles are stepwise formed after reduction of the same compound. The second reduction of ( YPh )3 CorMn IV Cl in pyridine gives a Mn(III) π-anion radical as opposed to a Mn(II) corrole with an unreduced π-ring system. The neutral, reduced and oxidized forms of each corrole were characterized by electrochemistry and UV-visible spectroelectrochemistry and comparisons are made between the UV-visible spectra and redox potentials of the compounds in different central metal oxidation states. An overall reduction/oxidation mechanism in the three solvents is proposed.

Molecular Cloning and Characterization of a Tumor-Associated, Growth-Related, and Time-Keeping Hydroquinone (NADH) Oxidase (tNOX) of the HeLa Cell Surface†

Biochemistry ◽  
2002 ◽  
Vol 41 (11) ◽  
pp. 3732-3741 ◽  
Author(s):  
Pin-Ju Chueh ◽  
Chinpal Kim ◽  
NaMi Cho ◽  
Dorothy M. Morré ◽  
D. James Morré
Keyword(s):  
Cell Surface ◽  
Hela Cell ◽  
Molecular Cloning ◽  
Nadh Oxidase
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