Assay of enzymatic activity by electrochemical detection of reduced coenzyme

Wallace, Thomas C.; Coughlin, Robert W.

doi:10.1016/0003-2697(77)90633-9

Cited by 17 publications

(1 citation statement)

References 14 publications

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“…Many current methods require the use of a labeled substrate, which is not only difficult to synthesize but may alter its interaction with the enzyme. Other methods based on electrochemical assays have also been reported but are typically limited to redox reactions. − …”

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confidence: 99%

Direct, Rapid, and Label-Free Detection of Enzyme–Substrate Interactions in Physiological Buffers Using CMOS-Compatible Nanoribbon Sensors

Droujinine

Rajan

et al. 2014

Nano Lett.

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We demonstrate the versatility of Al2O3-passivated Si nanowire devices ("nanoribbons") in the analysis of enzyme-substrate interactions via the monitoring of pH change. Our approach is shown to be effective through the detection of urea in phosphate buffered saline (PBS), and penicillinase in PBS and urine, at limits of detection of <200 μM and 0.02 units/mL, respectively. The ability to extract accurate enzyme kinetics and the Michaelis-Menten constant (Km) from the acetylcholine-acetylcholinesterase reaction is also demonstrated.

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mentioning

confidence: 99%

Direct, Rapid, and Label-Free Detection of Enzyme–Substrate Interactions in Physiological Buffers Using CMOS-Compatible Nanoribbon Sensors

Droujinine

Rajan

et al. 2014

Nano Lett.

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Rate of catalytic oxidation and decomposition of NADH by graphite in aqueous solutions

Wallace

Coughlin

1978

Biotech & Bioengineering

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SummaryGraphites of different manufacture and origin exert positive but different accelerations on the rate of oxidation of NADH to NAD' in aqueous solution; different proportions of the oxidized form of NAD retain enzymatic activity depending on the nature of the graphite. Oxidative pretreatment of the graphite surfaces increases the rates of NADH oxidation, but subsequent silanization of the surfaces to attach alkylamine groups causes the rates to decrease. The experimental results suggest the presence of at least two types of sites on graphite surfaces: one very reactive site which produces a high percentage of an enzymatically inactive reaction product of NADH and is itself deactivated during the course of reaction, and another type of site which promotes the oxidation of NADH to enzymatically active NAD+ in high yields.

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Potentiometric determination of coenzyme‐dependent oxidoreductase enzymes with recycling of the coenzyme

Wallace

Coughlin

1978

Biotech & Bioengineering

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SummaryBy enzymatically establishing a rapid (essentially equilibrium) coupling of a redox coenzyme such as NAD with the components of the ferrocyanide-fenicyanide halfcell (e.g., using excess diaphorase) the half-cell potential can be used to monitor another enzymatic reaction involving the same coenzyme. This approach provides a general, rapid potentiometric method of assaying coenzyme-dependent oxidoreductase enzymes. We show that these assay systems can be designed for multiple turnover of coenzyme (in our case NAD) during a single assay thereby amplifying the rate of electromotive force (emf) change with a concomitant increase in sensitivity of enzyme assay. This allows the use of small concentrations of coenzyme and extension of the range of enzyme concentrations that may be assayed.

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Assay of enzymatic activity by electrochemical detection of reduced coenzyme

Cited by 17 publications

References 14 publications

Direct, Rapid, and Label-Free Detection of Enzyme–Substrate Interactions in Physiological Buffers Using CMOS-Compatible Nanoribbon Sensors

Direct, Rapid, and Label-Free Detection of Enzyme–Substrate Interactions in Physiological Buffers Using CMOS-Compatible Nanoribbon Sensors

Rate of catalytic oxidation and decomposition of NADH by graphite in aqueous solutions

Potentiometric determination of coenzyme‐dependent oxidoreductase enzymes with recycling of the coenzyme

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