Influence of tryptophan mutation on the direct electron transfer of immobilized tobacco peroxidase

Olloqui‐Sariego, José Luis; Захарова, Г. С.; Poloznikov, Andrey; Calvente, Juan José; Hushpulian, Dmitry M.; Gorton, Lo; Andreu, Rafael

doi:10.1016/j.electacta.2020.136465

Cited by 12 publications

(18 citation statements)

References 51 publications

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“…In addition, a catalytic current for the oxidation of H 2 O 2 to O 2 occurring directly at the portion of electrode surface not covered by the enzyme (it can be identified as naked electrode) was observed (catalysis starting at approximately 0.4 V vs. SCE), which is in agreement with previously reported results. [55,67,68] Conversely, the r-TOP/p-PD/MWCNTs/G electrode platform showed a different electrochemical behavior both in nonturnover and turnover conditions, Figure 1B. The CV in the absence of H 2 O 2 did not show any redox waves maybe because r-TOP did not undergo any denaturation process due to the immobilization protocol (e. g., physical adsorption), Figure 1B (black curve).…”

Section: Electrochemical Characterization Of R-top Modified Electrodesmentioning

confidence: 98%

“…Although HRP and TOP show a similar reaction mechanism, the two enzymes exhibit different parameters, such as glycosylation, stability, isoelectric point and specificity for various electron donor substrates. [57][58][59] The common peroxidase reaction cycle proceeds through the following reaction steps: [60][61][62][63][64][65][66][67][68] Native…”

Section: Introductionmentioning

confidence: 99%

“…An enzymatically inactive form of peroxidase, denoted compound-III (oxidation state + 6), can be formed at high concentrations of peroxide especially when initially a low potential is applied transferring the ferric state into the ferrous state. [68] Besides the common peroxidase cycle, at pH 7 and applying a potential below 0, there is a second mechanism also called electro-Fenton reaction, where Fe 2 + reduces H 2 O 2 to produce a hydroxyl radical (•OH) and Fe 3 + , which is then reduced back at the electrode surface to Fe 2 + , thus restarting the cycle. At this point, it might be important to highlight that the continuous production of •OH would result in a drastic reduction of the operating life of the biosensor due to enzyme denaturation.…”

Section: Introductionmentioning

confidence: 99%

“…At this point, it might be important to highlight that the continuous production of •OH would result in a drastic reduction of the operating life of the biosensor due to enzyme denaturation. [67,68] Herein, we report on the development of a new electrode platform based on the immobilization of anionic recombinant tobacco peroxidase (r-TOP) onto p-phenylenediamine diazonium cation (p-PD) grafted carbon nanotubes. [69] This approach allowed to enhance the sensitivity, stability and selectivity of H 2 O 2 detection through electrical wiring of TOP by using glutaraldehyde as cross-linking agent between the p-PD diazonium cation grafted carbon nanotubes and the enzyme.…”

Section: Introductionmentioning

confidence: 99%

“…The DET approach results in a reduction current correlated to the concentration of peroxide in the solution. An enzymatically inactive form of peroxidase, denoted compound‐III (oxidation state +6), can be formed at high concentrations of peroxide especially when initially a low potential is applied transferring the ferric state into the ferrous state [68] …”

Section: Introductionmentioning

confidence: 99%

See 4 more Smart Citations

Highly Sensitive Hydrogen Peroxide Biosensor Based on Tobacco Peroxidase Immobilized on p‐Phenylenediamine Diazonium Cation Grafted Carbon Nanotubes: Preventing Fenton‐like Inactivation at Negative Potential

et al. 2021

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Herein, we present a novel electrode platform for H 2 O 2 detection based on the immobilization of recombinant Tobacco Peroxidase (r-TOP) onto graphite electrodes (G) modified with p-phenylenediamine (p-PD) diazonium cation grafted multiwalled carbon nanotubes (MWCNTs). The employment of both p-phenylenediamine moieties and covalent cross-linking by using glutaraldehyde allowed us to enhance the sensitivity, stability, and selectivity toward H 2 O 2 detection, as well as preventing enzyme inactivation due to the electro-Fenton reaction. This reaction continuously produces hydroxyl radicals, whose high and unselective reactivity is likely to reduce drastically the operating life of the biosensor. The protection against the electro-Fenton reaction is mainly ascribed to a beneficial enzyme immobilization leading to a correct orientation achieved through cross-linking the enzyme in combination with interaction between the uncoupled -NH 2 groups (mainly uncharged at pH 7, considering a pK a of 4.6) available on the electrode surface and the enzyme. In particular, the electrode based on the r-TOP/p-PD/MWCNTs/G platform showed a lower limit of detection of 1.8 μM H 2 O 2 , an extended linear range between 6 and 900 μM H 2 O 2 , as well as a significant increase in sensitivity (63.1 � 0.1 μA mM À 1 cm À 2 ) compared with previous work based on TOP. Finally, the r-TOP/p-PD/MWCNTs/G electrode was tested in several H 2 O 2 spiked food samples as a screening analytical method for the detection of H 2 O 2 .

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Section: Electrochemical Characterization Of R-top Modified Electrodesmentioning

confidence: 98%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Highly Sensitive Hydrogen Peroxide Biosensor Based on Tobacco Peroxidase Immobilized on p‐Phenylenediamine Diazonium Cation Grafted Carbon Nanotubes: Preventing Fenton‐like Inactivation at Negative Potential

et al. 2021

Self Cite

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Reduced graphene oxide/titanium carbide MXene nanocomposite‐modified electrode for electrochemical hemoglobin biosensor

Sun

Wang

Ding

et al. 2021

J Chinese Chemical Soc

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In this work, reduced graphene oxide (rGO) and titanium carbide (Ti 3 C 2 T x ) nanocomposite was prepared by the self-assembly method and used for electrode modification. The rGO-Ti 3 C 2 T x nanocomposite was examined by scanning electron microscopy, transmission electron microscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. Then, an electrochemical hemoglobin (Hb) biosensor was prepared on the nanocomposite-modified electrode and used for the determination of trichloroacetic acid (TCA) and hydrogen peroxide (H 2 O 2 ). Direct electrochemistry of Hb on the modified electrode was examined with the calculations of the electron transfer number, electron transfer coefficient, and the reaction rate constant. The presence of the rGO-Ti 3 C 2 T x nanocomposite on the electrode can improve the effective surface area and biocompatibility of the electrode interface, obtaining a higher electron transfer rate. Furthermore, this electrochemical Hb biosensor exhibited excellent stability, reproducibility, and repeatability in TCA and H 2 O 2 analyses.direct electrochemistry, electrocatalysis, electrochemical biosensor, hemoglobin, reduced graphene oxide, Ti 3 C 2 T x

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Phosphorylation of cytochrome c at tyrosine 48 finely regulates its binding to the histone chaperone SET/TAF‐Iβ in the nucleus

Tamargo‐Azpilicueta,

Casado‐Combreras,

Giner‐Arroyo

et al. 2024

Protein Science

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Post‐translational modifications (PTMs) of proteins are ubiquitous processes present in all life kingdoms, involved in the regulation of protein stability, subcellular location and activity. In this context, cytochrome c (Cc) is an excellent case study to analyze the structural and functional changes induced by PTMS as Cc is a small, moonlighting protein playing different roles in different cell compartments at different cell‐cycle stages. Cc is actually a key component of the mitochondrial electron transport chain (ETC) under homeostatic conditions but is translocated to the cytoplasm and even the nucleus under apoptotic conditions and/or DNA damage. Phosphorylation does specifically alter the Cc redox activity in the mitochondria and the Cc non‐redox interaction with apoptosis‐related targets in the cytoplasm. However, little is known on how phosphorylation alters the interaction of Cc with histone chaperones in the nucleus. Here, we report the effect of Cc Tyr48 phosphorylation by examining the protein interaction with SET/TAF‐Iβ in the nuclear compartment using a combination of molecular dynamics simulations, biophysical and structural approaches such as isothermal titration calorimetry (ITC) and nuclear magnetic resonance (NMR) and in cell proximity ligation assays. From these experiments, we infer that Tyr48 phosphorylation allows a fine‐tuning of the Cc‐mediated inhibition of SET/TAF‐Iβ histone chaperone activity in vitro. Our findings likewise reveal that phosphorylation impacts the nuclear, stress‐responsive functions of Cc, and provide an experimental framework to explore novel aspects of Cc post‐translational regulation in the nucleus.

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Influence of tryptophan mutation on the direct electron transfer of immobilized tobacco peroxidase

Cited by 12 publications

References 51 publications

Highly Sensitive Hydrogen Peroxide Biosensor Based on Tobacco Peroxidase Immobilized on p‐Phenylenediamine Diazonium Cation Grafted Carbon Nanotubes: Preventing Fenton‐like Inactivation at Negative Potential

Highly Sensitive Hydrogen Peroxide Biosensor Based on Tobacco Peroxidase Immobilized on p‐Phenylenediamine Diazonium Cation Grafted Carbon Nanotubes: Preventing Fenton‐like Inactivation at Negative Potential

Reduced graphene oxide/titanium carbide MXene nanocomposite‐modified electrode for electrochemical hemoglobin biosensor

Phosphorylation of cytochrome c at tyrosine 48 finely regulates its binding to the histone chaperone SET/TAF‐Iβ in the nucleus

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