Bilirubin oxidase bioelectrocatalytic cathodes: the impact of hydrogen peroxide

Milton, Ross D.; Giroud, Françoise; Thumser, Alfred E.; Minteer, Shelley D.; Slade, Robert C. T.

doi:10.1039/c3cc47689h

Cited by 77 publications

(90 citation statements)

References 29 publications

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“…The specific orientation and association of laccase and BOx to their substrates or substrate mimics provides strong evidence that the enzyme must remain partially correctly folded (as a minimum). Knowledge surrounding the inhibition of these enzymes by small halide anions has resulted in studies that provide additional experimental evidence to support the argument that O 2 reduction is facilitated by oriented intact enzyme versus dissociated inhibitor results in the complete loss of direct bioelectrocatalysis (figure 3) [40,48]. Additionally, loadings of laccase onto electrodes at quantities greater than an expected monolayer result in some enzyme that is not orientated, and thus does not undergo direct bioelectrocatalysis.…”

Section: Direct Bioelectrocatalysis Of Metalloenzymesmentioning

confidence: 96%

“…The addition of an additional T1 Cu centre electron mediator (such as ABTS) increases the catalytic current observed on the electrode, due to a mixture of MET and DET pathways. The addition of 150 mM Cl 2 typically quenches this additional MET pathway (due to Cl 2 competitive inhibition at the T1 Cu centre), providing further evidence for enzymatic orientation [40,48]. Very recently, Dagys et al [51] reported on an efficient laccase bioelectrode whereby ET via the T1 Cu centre was negated altogether and DET was established between an Au electrode and the TNC of the enzyme, achieving high catalytic current densities of nearly 1 mA cm 22 (at pH 4).…”

Section: Direct Bioelectrocatalysis Of Metalloenzymesmentioning

confidence: 99%

“…Typically, polyaromatic hydrocarbons (anthracene, naphthalene and derivatives thereof ) are the most commonly employed orientational agents [40 -44]. In the case of BOx, efficient DET can be afforded by immobilization onto multi-walled carbon nanotubes, using charged multi-walled carbon nanotubes, immobilized polyaromatic hydrocarbons and even natural substrates (bilirubin and its metabolites) [33,[45][46][47][48][49].…”

Section: Direct Bioelectrocatalysis Of Metalloenzymesmentioning

confidence: 99%

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Direct enzymatic bioelectrocatalysis: differentiating between myth and reality

Milton

Minteer

2017

J. R. Soc. Interface.

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158

148

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Enzymatic bioelectrocatalysis is being increasingly exploited to better understand oxidoreductase enzymes, to develop minimalistic yet specific biosensor platforms, and to develop alternative energy conversion devices and bioelectrosynthetic devices for the production of energy and/or important chemical commodities. In some cases, these enzymes are able to electronically communicate with an appropriately designed electrode surface without the requirement of an electron mediator to shuttle electrons between the enzyme and electrode. This phenomenon has been termed direct electron transfer or direct bioelectrocatalysis. While many thorough studies have extensively investigated this fascinating feat, it is sometimes difficult to differentiate desirable enzymatic bioelectrocatalysis from electrocatalysis deriving from inactivated enzyme that may have also released its catalytic cofactor. This article will review direct bioelectrocatalysis of several oxidoreductases, with an emphasis on experiments that provide support for direct bioelectrocatalysis versus denatured enzyme or dissociated cofactor. Finally, this review will conclude with a series of proposed control experiments that could be adopted to discern successful direct electronic communication of an enzyme from its denatured counterpart.

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Section: Direct Bioelectrocatalysis Of Metalloenzymesmentioning

confidence: 96%

Section: Direct Bioelectrocatalysis Of Metalloenzymesmentioning

confidence: 99%

Section: Direct Bioelectrocatalysis Of Metalloenzymesmentioning

confidence: 99%

See 1 more Smart Citation

Direct enzymatic bioelectrocatalysis: differentiating between myth and reality

Milton

Minteer

2017

J. R. Soc. Interface.

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158

148

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“…The most common "Blue" MCO enzymes are ascorbate oxidase (AOx), laccase (Lac), and bilirubin oxidase (BOx) that can act as excellent biocathode materials for biofuel cell applications [5,6]. These enzymes are more active and selective than the state-of-the-art electrocatalyst platinum because BOx can promote a four-electron reduction of oxygen [7,8], leading directly to water rather than production of significant amount of hydrogen peroxide (H 2 O 2 -2-electron exchange) [9]. It has been shown previously that BOx demonstrated high electrocatalytic oxygen reduction and low overpotential necessary to catalyze the reaction and a turnover rate of 0.7 O 2 per Cu⋅s −1 , while Pt catalysts turnover rate is three times lower at overpotential of 350 mV [2,10].…”

Section: Introductionmentioning

confidence: 99%

Enhancement of Electrochemical Performance of Bilirubin Oxidase Modified Gas Diffusion Biocathode by Porphyrin Precursor

Pinchon

Arugula

Pant

et al. 2018

Advances in Physical Chemistry

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Recent studies have focused on tailoring the catalytic currents of multicopper oxidase (MCO) enzymes-based biocathodes to enhance oxygen reduction. Biocathodes modified with natural substrates specific for MCO enzymes demonstrated drastic improvement for oxygen reduction. Performance of 1-pyrenebutanoic acid, succinimidyl ester (PBSE), and 2,5-dimethyl-1-phenyl-1H-pyrrole-3-carbaldehyde (Di-Carb) oriented bilirubin oxidase (BOx) modified gas diffusion biocathode has been highly improved by incorporating hematin, a porphyrin precursor as electron transfer enhancement moiety. Hematin modified electrodes demonstrated direct electron transfer reaction of BOx exhibiting larger O 2 reduction in current density in phosphate buffer solution (pH 7.0) without the need of a mediator. A remarkable improvement in the catalytic currents with 2.5-fold increase compared to non-hematin modified oriented BOx electrodes was achieved. Moreover, a mediatorless and compartmentless glucose/O 2 biofuel cell based on DET-type bioelectrocatalysis via the BOx cathode and the glucose dehydrogenase (GDH) anode demonstrated peak power densities of 1 mW/cm 2 at pH 7.0 with 100 mM glucose/10 mM NAD fuel. The maximum current density of 1.6 mA/cm 2 and the maximum power density of 0.4 mW/cm 2 were achieved at 300 mV with nonmodified BOx cathode, while 3.5 mA/cm 2 and 1.1 mW/cm 2 of current and power density were achieved with hematin modified cathode. The performance improved 2.4 times which attributes to the hematin acting as a natural precursor and activator for BOx activity enhancement.

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“…9,13,19 Recent studies, however, determined that certain membrane-less EFC configurations (favorable to lower overall device cost and size) can present further problems for laccase-based biocathodes, whereby oxidoreductases utilized at EFC bioanodes (such as glucose oxidase * Electrochemical Society Student Member.…”

mentioning

confidence: 99%

Investigating the Reversible Inhibition Model of Laccase by Hydrogen Peroxide for Bioelectrocatalytic Applications

Milton¹

2014

J. Electrochem. Soc.

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The reversible inhibition of laccase by H 2 O 2 as a bioelectrocatalyst was studied in mediated-and direct electron transfer-based configurations to understand the differences in mechanism. The reversible inhibition of laccase follows a noncompetitive inhibition model when 2,2 -azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) is used as an electron mediator, whereas laccase is inhibited by an uncompetitive inhibition model when anthracene-moieties are used to intelligently "dock" laccase to electrodes (consisting of multi-walled carbon nanotubes, MWCNTs) which afford direct electron transfer (DET). This further confirms the efficient orientation of laccase onto suitably-designed docking moieties for bioelectrocatalysis applications. 1-5 Along with some other MCOs (such as bilirubin oxidase, BOx), laccase contains 3 different copper centers. A type-1 copper center (T1 Cu) is proximally located within the enzyme structure and is responsible for the single-electron oxidation of phenolic-type substrates, and a further type-2 copper center (T2 Cu) and 2 further type-3 copper centers (T3 Cu) are combined in a tri-nuclear cluster (TNC), which is responsible for the 4-electron reduction of O 2 to H 2 O. Following the oxidation of substrates at the T1 Cu site, electrons are quickly and individually transferred to the TNC via a His-Cys-His tripeptide chain.6,7 Although laccase (from Trametes versicolor) is reported to optimally reduce O 2 at acidic pH (which may limit its incorporation within implantable EFCs) further complications can be found within a physiological setting, where laccase can be inhibited by Cl − (approximately 150 mM physiological concentration) via a competitive inhibition model whereby Cl − can compete against certain electron mediators at the T1 Cu site of the enzyme. 8,9 Laccase can be intelligently orientated (or "docked") onto electrode architectures whereby moieties with structural similarities to the natural substrates of laccase (oxidized at the T1 site) are incorporated on specifically-designed electrode architectures, which subsequently allow direct electron transfer (DET).2,4,10-14 Efficient mediated electron transfer (MET) has also been demonstrated using mediators such as 2,2'-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) or osmium-based complexes 1,[15][16][17] and comparison between orientationally-driven DET and MET of laccase (with ABTS) has been reported, contrasting catalytic current densities that can be achieved with both electron transfer methods.18 Such electrode architectures can be capable of demonstrating increased resistance to Cl − inhibition, since the moieties used for docking can efficiently out-compete Cl − at the T1 site and therefore permit electron transfer. 9,13,19 Recent studies, however, determined that certain membrane-less EFC configurations (favorable to lower overall device cost and size) can present further problems for laccase-based biocathodes, whereby oxidoreductases utilized at EFC bioanodes (such as glucose oxidase * Electrochemical Soc...

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Bilirubin oxidase bioelectrocatalytic cathodes: the impact of hydrogen peroxide

Cited by 77 publications

References 29 publications

Direct enzymatic bioelectrocatalysis: differentiating between myth and reality

Direct enzymatic bioelectrocatalysis: differentiating between myth and reality

Enhancement of Electrochemical Performance of Bilirubin Oxidase Modified Gas Diffusion Biocathode by Porphyrin Precursor

Investigating the Reversible Inhibition Model of Laccase by Hydrogen Peroxide for Bioelectrocatalytic Applications

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