Temperature and pH effects on cytochrome c oxidase immobilized in an electrode-supported lipid bilayer membrane

Rhoten, Melissa C.; Burgess, James D.; Hawkridge, Fred M.

doi:10.1016/s0013-4686(00)00359-5

Cited by 22 publications

(21 citation statements)

References 46 publications

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“…No redox response of a lipidmodified electrode in the absence of the CcO was observed. This result is identical with those obtained in previous investigations [33,36]. Potassium cyanide (0.5 lM in 0.1 M phosphate buffer) was introduced E (mV) vs Ag/AgCl to the sample compartment of the cell for approximately 10 min under open circuit conditions, and another CV was obtained (Fig.…”

Section: Resultssupporting

confidence: 90%

“…1). The oxidase molecules are in direct communication with the underlying metal surface as evidenced by the cyclic voltammetric response (in the absence of chemical modification or mediators) and enzyme-mediated electron transfer between reduced cytochrome c in solution and the underlying metal electrode [36][37][38]. It has also been recently demonstrated that this system is useful for the electroreduction of oxygen, a characteristic that could potentially be exploited in biofuel cell applications [39].…”

Section: Introductionmentioning

confidence: 99%

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Characterization of cyanide binding to cytochrome c oxidase immobilized in electrode-supported lipid bilayer membranes

Kelly²,

Hawkridge

et al. 2005

Journal of Electroanalytical Chemistry

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Section: Resultssupporting

confidence: 90%

Section: Introductionmentioning

confidence: 99%

Characterization of cyanide binding to cytochrome c oxidase immobilized in electrode-supported lipid bilayer membranes

Kelly²,

Hawkridge

et al. 2005

Journal of Electroanalytical Chemistry

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“…The results are consistent with earlier work that indicates that the cytochrome c oxidase immobilized in the electrode-supported lipid bilayer membrane may retain its proton-pumping capability. Previous cyclic voltammetric studies at varying pH values have also yielded similar results (i.e., larger current responses at lower pH) [15]. The interface between the electrode and the bilayer membrane is not atomically smooth and is likely to harbor regions containing buffer solutions that could provide protons for pumping in the system described here.…”

supporting

confidence: 77%

“…The effect of the system temperature on the voltammetric response of cytochrome c oxidase immobilized in an electrode-supported lipid bilayer membrane was investigated previously [15]. The results showed that the cytochrome c oxidase maintained its electron-transfer properties at temperature in excess of 808.…”

mentioning

confidence: 99%

Electroreduction of Oxygen by Cytochrome c Oxidase Immobilized in Electrode‐Supported Lipid Bilayer Membranes

L¹,

Hawkridge²,

Rhoten³

2004

Chemistry & Biodiversity

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Cytochrome c oxidase is the terminal enzyme in mammalian respiration, and one of its main functions is to catalyze the reduction of oxygen under physiological conditions. Direct reduction of oxygen at electrodes requires application of substantial overpotentials. In this work, bovine cytochrome c oxidase has been immobilized in electrode-supported lipid bilayer membranes to investigate the electroreduction of oxygen under flow conditions. The effect that temperature, solution pH, and solution composition have on the reduction of oxygen by this novel enzyme-modified electrode is reported. Results indicate that the electroreduction of oxygen is most pronounced at low pH (6.4) and elevated temperature (38 degrees). At an applied potential of -350 mV vs. Ag/AgCl (1M KCl), a current density of ca. 7 microA/cm2 was obtained. The current responses obtained at these electrodes are stable over a period of ca. 10-14 days (10-15% decrease in response). The cytochrome c oxidase-modified electrodes described here could potentially be used for the direct electroreduction of oxygen to water in a biofuel cell.

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“…The immobilized enzymes directly transfer electrons to the platinum electrodes measuring the local concentration of the reaction products. 33, 34 Changes in oxygen consumption were measured amperometrically (−0.45 V) and all electrode potentials were set versus a Ag/AgCl reference electrode. Acidification rates were measured by traditional operation of the Cytosensor instrument as specified by the manufacturer.…”

Section: Methodsmentioning

confidence: 99%

Metabolic Impact of 4-Hydroxynonenal on Macrophage-Like RAW 264.7 Function and Activation

Harry

Hiatt

Kimmel

et al. 2012

Chem. Res. Toxicol.

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Metabolic profiling of macrophage metabolic response upon exposure to 4-hydroxynonenal (HNE) demonstrates that HNE does not simply inactivate superoxide generating enzymes but could also be responsible for the impairment of downfield signaling pathways. Multianalyte microphysiometry (MAMP) was employed to simultaneously measure perturbations in extracellular acidification, lactate production and oxygen consumption for the examination of aerobic and anaerobic pathways. Combining the activation of oxidative burst with phorbol myristate acetate (PMA) and the immunosuppression with HNE, the complex nature of HNE toxicity was determined to be concentration- and time-dependent. Further analysis was utilized to assess the temporal effect of HNE on reactive oxygen species (ROS) production and on protein kinase C (PKC). Increased levels of HNE with decreasing PKC activity suggest PKC is a target for HNE adductation prior to oxidative burst. Additionally, localization of PKC to the cell membrane was prevented with the introduction of HNE, demonstrating a consequence of HNE adductation on NADPH activation. The impairment of ROS by HNE suggests HNE has a greater role in foam cell formation and tissue damage than is already known. Although work has been performed to understand the effect of HNE’s regulation of specific signaling pathways, details regarding its involvement in cellular metabolism as a whole are generally unknown. This study examines the impact of HNE on macrophage oxidative burst and identifies PKC as a key protein for HNE suppression and eventual metabolic response.

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Temperature and pH effects on cytochrome c oxidase immobilized in an electrode-supported lipid bilayer membrane

Cited by 22 publications

References 46 publications

Characterization of cyanide binding to cytochrome c oxidase immobilized in electrode-supported lipid bilayer membranes

Characterization of cyanide binding to cytochrome c oxidase immobilized in electrode-supported lipid bilayer membranes

Electroreduction of Oxygen by Cytochrome c Oxidase Immobilized in Electrode‐Supported Lipid Bilayer Membranes

Metabolic Impact of 4-Hydroxynonenal on Macrophage-Like RAW 264.7 Function and Activation

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