Some properties of an NADH-benzyl viologen reductase from azotobacter vinelandii

Nagai, Yuhki; Elleway, R. F.; Nicholas, D. J. D.

doi:10.1016/0005-2728(68)90004-2

Cited by 6 publications

(3 citation statements)

References 15 publications

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“…It should be noted that Benzyl Viologen has a much greater stimulatory effect on NAD+ reduction in whole cells compared with the extract (Table IV) and may suggest that a factor or enzyme is required for activity with Benzyl Viologen. Nagi et al (1968) have shown a specific NAD+-Benzyl Viologen reductase in Azobacter vinelandii which catalyzes the reversible transfer of electrons between NAD+ and Benzyl Viologen independent of ferredoxin and hydrogenase.…”

Section: Discussionmentioning

confidence: 99%

Structural and catalytic properties of hydrogenase from Chromatium

Gitlitz¹,

Krasna²

1975

Biochemistry

124

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The enzyme hydrogenase, from the photosynthetic bacterium Chromatium, was purified to homogeneity after solubilization of the particulate enzyme with deoxycholate. The purification procedure included ammonium sulfate fractionation, treatment with manganous phosphate gel, heating at 63 degrees, DEAE-cellulose chromatography, and isoelectric focusing. The last step gave two active enzyme fractions with isoelectric points of 4.2 and 4.4. It was shown that the two fractions were different forms of the same protein. The enzyme was obtained in 23% yield and was purified 1700-fold. The enzyme had a molecular weight of 98,000, a sedimentation coefficient of 5.16 S and gave a single protein and activity band on disc gel electrophoresis. Sodium dodecyl sulfate gel electrophoresis gave a single band of mol wt 50,000, suggesting that the active enzyme was composed of two subunits of the same molecular weight. The pure hydrogenase contained four atoms of iron and four atoms of acid-labile sulfide, and had a visible absorption peak at 410 nm. Electron paramagnetic resonance (EPR) spectroscopy at 10--15 K showed a free-radical signal at g' = 2.003 in the oxidized enzyme and signals at g' = 2.2 and 2.06 in the reduced enzyme. These findings suggest that Chromatium hydrogenase is an iron-sulfur protein. The pure hydrogenase catalyzed the exchange reaction between H2 and HDO or HTO, the reduction of Benzyl Viologen and Methylene Blue, and the evolution of hydrogen from reduced Methyl Viologen. The mechanism of hydrogen activation was shown to be heterolytic cleavage to an enzyme hydride and a proton. Hydrogenase could not catalyze reduction of pyridine nucleotides or ferredoxin with H2. The effect of pH and various inhibitors on the enzymatic activity has been studied.

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Section: Discussionmentioning

confidence: 99%

Structural and catalytic properties of hydrogenase from Chromatium

Gitlitz¹,

Krasna²

1975

Biochemistry

124

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“…related to the methyl-(benzyl) viologen/hydrogenase assay [28][29][30][31][32] the electrochemical detection of reduced viologen dendrimer species in single mammalian cells could be possible. Another intriguing problem to be tackled is the preference of groove binding reported for small viologen oligomers with dsDNA 19 and the condensation of DNA with viologen dendrimers reported in the current paper.…”

Section: Resultsmentioning

confidence: 99%

Alkylene-bridged viologen dendrimers: versatile cell delivery tools with biosensing properties

et al. 2014

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The synthesis of two types of viologen dendrimers with peripheral carboxyl groups is described. Their interaction with plasmid DNA and CT-DNA and the influence of time evolution and electrolyte on dendriplex formation have been electrochemically investigated. A negative potential shift appearing in the cyclic voltammograms of the dendrimers indicates dendriplex formation on the time scale of 15 to 19 minutes, i.e. similar to those determined empirically for other dendrimer types. The presence or absence of the negative potential shift can be used to check the stability towards sodium chloride and different cell growth media directing to sucrose for cell incubation experiments. The electrolyte content of commercially available cell growth media inhibits the dendriplex formation in solution prior to plasmid addition.Furthermore, a low salt stability of 20 mM sodium chloride for viologen dendriplexes has been confirmed, also recommending the use of lysosomotropic sucrose. The two types of viologen dendrimers have been combined with two plasmids differing in the number of base pairs. Four immortal cell lines have been tested to check the suitability of viologen dendriplexes as gene delivery systems. Probably due to the absence of terminal amino groups and endosomolytic substances only a small transfection efficiency of dendriplexes was achieved at low pH, generally excluding in vivo applications. With the larger pHSV-eGFP plasmid (5743 bp) no transfected cells were observed indicating a preference for shorter plasmids.

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“…This hypothetical compound was lost during thylakoid preparation. An Azotobacter vinelandii enzyme (20), catalyzed this NADP reduction, with benzyl viologen but not paraquat as the electron donor. However, such activity has not been detected in chloroplasts.…”

Section: Ptraquat (Jam)mentioning

confidence: 99%

Benzyl Viologen-Mediated Counteraction of Diquat and Paraquat Phytotoxicities

Lewinsohn¹,

Gressel²

1984

Plant Physiol.

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There was reason from bacterial and algl systems to expect that pretreatments with a paraquat analog might confer tolerance against a subsequent paraquat treatment. Thus, a series of compounds were tested for protective activity agait bipyridinium herbicides. These included other bipyridinium compounds and derivatives, as well as compounds having similar or more positive redox potentials than paraquat and compounds known to increase or maintain high superoxide dismutase activity levels in plants.

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Some properties of an NADH-benzyl viologen reductase from azotobacter vinelandii

Cited by 6 publications

References 15 publications

Structural and catalytic properties of hydrogenase from Chromatium

Structural and catalytic properties of hydrogenase from Chromatium

Alkylene-bridged viologen dendrimers: versatile cell delivery tools with biosensing properties

Benzyl Viologen-Mediated Counteraction of Diquat and Paraquat Phytotoxicities

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