Electrodes modified with lipid membranes to study quinone oxidoreductases

Weiss, Sophie A.; Jeuken, Lars J. C.

doi:10.1042/bst0370707

Cited by 11 publications

(7 citation statements)

References 46 publications

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“…We have previously shown that tBLMs can be used to study the enzyme kinetics of quinone converting enzymes like c bo 3 using voltammetric methods. [13, 18, 19] In this method, ubiquinone in the tBLM is electrochemically reduced by the electrode and after diffusion to c bo 3 ubiquinol is catalytically oxidised, creating a redox loop. By measuring the electron consumption at the surface (the electrode current), the enzyme activity is thus established.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

A study of cytochrome bo3 in a tethered bilayer lipid membrane

Weiss

Bushby

Evans

et al. 2010

Biochimica et Biophysica Acta (BBA) - Bioenergetics

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An assay has been developed in which the activity of an ubiquinol oxidase from Escherichia coli, cytochrome bo(3) (cbo(3)), is determined as a function of the hydrophobic substrate ubiquinol-10 (UQ-10) in tethered bilayer lipid membranes (tBLMs). UQ-10 was added in situ, while the enzyme activity and the UQ-10 concentration in the membrane have been determined by cyclic voltammetry. Cbo(3) is inhibited by UQ-10 at concentrations above 5-10 pmol/cm(2), while product inhibition is absent. Cyclic voltammetry has also been used to characterise the effects of three inhibitors; cyanide, inhibiting oxygen reduction; 2-n-Heptyl-4-hydroxyquinoline N-oxide (HQNO), inhibiting the quinone oxidation and Zn(II), thought to block the proton channels required for oxygen reduction and proton pumping activity. The electrochemical behaviour of cbo(3) inhibited with HQNO and Zn(II) is almost identical, suggesting that Zn(II) ions inhibit the enzyme reduction by quinol, rather than oxygen reduction. This suggests that at Zn(II) concentration below 50µM the proton release of cbo(3) is inhibited, but not the proton uptake required to reduce oxygen to water.

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Section: Introductionmentioning

confidence: 99%

“…[18] More recently, we have prepared tBLMs from total inner membrane extract from E. coli . [13, 19] The advantage of latter system is that no complex or harsh purification procedures are used and that the protein of interest is permanently retained within its natural membrane environment.…”

Section: Introductionmentioning

confidence: 99%

A study of cytochrome bo3 in a tethered bilayer lipid membrane

Weiss

Bushby

Evans

et al. 2010

Biochimica et Biophysica Acta (BBA) - Bioenergetics

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“…The work speculated that the stacking of the flakes is due to the natural chemical adhesions caused by the quinone 71 , which is responsible for the hydrophobic terminated layer surfaces in all the samples. Hydrophobic surface promotes cohesion between the nanostructures 72 – 74 . This can be visibly proven by the less dispersion and easy sedimentation at the bottom part of the glass vial.…”

Section: Resultsmentioning

confidence: 99%

The physical and optical investigations of the tannic acid functionalised Cu-based oxide nanostructures

Lah

Murthy

Zubir

2022

Sci Rep

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The need for a mild, low-cost, green environment that is able to produce exotic properties of output nanostructures is appealing nowadays. Employing these requirements, the copper (Cu)—based oxide nanostructures have been successfully synthesised via one-pot reaction using biocompatible natural polyphenol, tannic acid (TA) as both the reducing agent and stabiliser at 60, 70 and 80 °C. The structural and optical studies disclosed the effect of TA on the surface morphology, phase purity, elemental composition, optical microstrain and optical intrinsic energy of this mixed Cu2O and CuO nanostructures. The optically based method describes the comparative details of the multi-band gap in the presence of more than one element with overlapping spectra from the first-derivative absorbance curve $$\frac{\Delta E}{\Delta A}$$ Δ E Δ A and the exponential absorbance of Urbach tail energy $${E}_{U}$$ E U towards the conventional Tauc bandgap. The $$\frac{\Delta E}{\Delta A}$$ Δ E Δ A demonstrates that the pronounced effect of TA that Cu2O and CuO nanostructures creates much sensitive first-derivative bandgap output compared to the Tauc bandgap. The results also show that the $${E}_{U}$$ E U reduced as the temperature reaches 70 °C and then experienced sudden increase at 80 °C. The change in the pattern is parallel to the trend observed in the Williamson–Hall microstrain and is evident from the variations of the mean crystallite size $${D}_{m}$$ D m which is also a cause response to the change in temperature or pH. Therefore, the current work has elucidated that the structural and optical correlations on the as-synthesised Cu2O and CuO nanostructures in the presence of TA were the combined reaction of pH change and the ligand complexation reactions. The acquired results suggest a more comprehensive range of studies to further understand the extent relationship between the physical and optical properties of TA functionalised Cu-based oxide nanostructures.

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“…Quinone oxidoreductases are a type of membrane-bound enzymes that catalyze redox processes of the quinone pool in cell membranes. They can be reconstituted on sBLMs formed over electrodes, in which lipophilic quinones that are embedded in the sBLM act as redox mediators with the electrode [67]. Jeuken and co-workers studied this strategy for an ubiquinol oxidase (cytochrome bo3 from Escherichia coli), which couples the oxidation of ubiquinol to ubiquinone with the reduction of O 2 to H 2 O [68].…”

Section: Reconstitution Of Membrane-bound Enzyme On Electrodesmentioning

confidence: 99%

Electrochemical Biosensors Based on Membrane-Bound Enzymes in Biomimetic Configurations

Álvarez-Malmagro

García-Molina

Lacey

2020

Sensors

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In nature, many enzymes are attached or inserted into the cell membrane, having hydrophobic subunits or lipid chains for this purpose. Their reconstitution on electrodes maintaining their natural structural characteristics allows for optimizing their electrocatalytic properties and stability. Different biomimetic strategies have been developed for modifying electrodes surfaces to accommodate membrane-bound enzymes, including the formation of self-assembled monolayers of hydrophobic compounds, lipid bilayers, or liposomes deposition. An overview of the different strategies used for the formation of biomimetic membranes, the reconstitution of membrane enzymes on electrodes, and their applications as biosensors is presented.

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Electrodes modified with lipid membranes to study quinone oxidoreductases

Cited by 11 publications

References 46 publications

A study of cytochrome bo3 in a tethered bilayer lipid membrane

A study of cytochrome bo3 in a tethered bilayer lipid membrane

The physical and optical investigations of the tannic acid functionalised Cu-based oxide nanostructures

Electrochemical Biosensors Based on Membrane-Bound Enzymes in Biomimetic Configurations

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