Effects of pressure and temperature on the reactions of horseradish peroxidase with hydrogen cyanide and hydrogen peroxide

Ralston, Isobel M.; Dunford, H. Brian; Wauters, Joost; Heremans, Karel

doi:10.1016/s0006-3495(81)84731-5

Cited by 12 publications

(3 citation statements)

References 14 publications

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“…It is noted that the τ does not exhibit the typical dependence on the dispersion temperature. Instead of a simple linear relationship (a conventional Arrhenius-type dependence) between ln(τ −1 ) and T −1 reported previously for the HRP-catalyzed coupling reaction of phenols via decomposition of H 2 O 2 , 57,58 the change of ln(τ −1 ) with T −1 can be divided into three regions: at the dispersion temperatures of ≤18 °C (i.e., T −1 ≥ 3.43 × 10 −3 K −1 ), the ln(1/τ) increases with temperature, whereas in the region of ca. 18−33 °C (i.e., 3.27 × 10 −3 K −1 < T −1 < 3.43 × 10 −3 K −1 ) the ln(τ −1 ) decreases with increasing temperature, and at ≥33 °C (i.e., T −1 ≤ 3.27 × 10 −3 K −1 ) the ln(τ −1 ) increases again; in particular, the ln(τ −1 ) shows a local minimum right at the volume phase transition temperature (VPTT) of the HSM microgels.…”

Section: Resultsmentioning

confidence: 92%

Synthesis and Characterization of Dextran–Tyramine-Based H₂O₂-Sensitive Microgels

et al. 2014

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We report a type of polymer microgel that can undergo a rapid and highly sensitive volume change upon adding H 2 O 2 . Such a H 2 O 2 -sensitive microgel is made of dextran−tyramine and horseradish peroxidase (HRP), which are interpenetrated in chemically cross-linked gel networks of poly(oligo(ethylene glycol) methacrylates). Unlike the H 2 O 2 -sensitive microgels reported in previous arts that typically involve degradation processes related to H 2 O 2 -induced cleavability of specific bonds, the proposed microgels can shrink upon adding H 2 O 2 owing to the HRP-catalyzed coupling reaction of tyramine residues via decomposition of H 2 O 2 . While a fast (<10 s) and stable shrinkage of the microgels can be reached upon adding H 2 O 2 over a concentration range 50.0 μM−1.0 mM, the response time can be modulated by the dispersion temperature in a nonmonotonous way over 10−38°C. With the microgels as probes, the H 2 O 2 detection limit was approximately 6.8 μM. In a combined use of the microgels with glucose oxidase for glucose detection, the glucose detection limit was approximately 83.1 μM.

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Section: Resultsmentioning

confidence: 92%

Synthesis and Characterization of Dextran–Tyramine-Based H₂O₂-Sensitive Microgels

et al. 2014

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“…Nondenaturing hydrostatic pressure is an established method for demonstrating the sensitivity of enzyme turnover to changes in the equilibrium of protein conformational states. − As a broad framework, one expects a significant pressure dependence on enzyme activity, in cases where the turnover is affected by the protein’s conformational dynamics. − We have previously demonstrated a correlation of a pressure-dependent Δ C P ‡ with differences in global protein flexibility Figure A,B shows the combined pressure–temperature dependence of k cat for HRP and the resulting pressure dependence of the values extracted by fitting to eq and given in Table .…”

Section: Resultsmentioning

confidence: 99%

Rigidifying a De Novo Enzyme Increases Activity and Induces a Negative Activation Heat Capacity

et al. 2021

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Conformational sampling profoundly impacts the overall activity and temperature dependence of enzymes. Peroxidases have emerged as versatile platforms for high-value biocatalysis owing to their broad palette of potential biotransformations. Here, we explore the role of conformational sampling in mediating activity in the de novo peroxidase C45. We demonstrate that 2,2,2-triflouoroethanol (TFE) affects the equilibrium of enzyme conformational states, tending toward a more globally rigid structure. This is correlated with increases in both stability and activity. Notably, these effects are concomitant with the emergence of curvature in the temperature-activity profile, trading off activity gains at ambient temperature with losses at high temperatures. We apply macromolecular rate theory (MMRT) to understand enzyme temperature dependence data. These data point to an increase in protein rigidity associated with a difference in the distribution of protein dynamics between the ground and transition states. We compare the thermodynamics of the de novo enzyme activity to those of a natural peroxidase, horseradish peroxidase. We find that the native enzyme resembles the rigidified de novo enzyme in terms of the thermodynamics of enzyme catalysis and the putative distribution of protein dynamics between the ground and transition states. The addition of TFE apparently causes C45 to behave more like the natural enzyme. Our data suggest robust, generic strategies for improving biocatalytic activity by manipulating protein rigidity; for functional de novo protein catalysts in particular, this can provide more enzyme-like catalysts without further rational engineering, computational redesign, or directed evolution.

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“…Due to difficulty in access, many of these are optical in character, and are better suited to transparent samples than to foods. Techniques such as circular dichroism (Harris and others ), optical rotation (Andersen and Gronlund ), fluorescence (Ralston and others ), X‐ray diffraction (Stamatoff and others ), Raman spectroscopy (Yager and Peticolas ), and dynamic light scattering (Ceuterick and others ). Chemical relaxation techniques such as pressure jump (Heremans and others ), nanosecond temperature jump (Liphard ), and flash photolysis (Hasinoff ) have been used at high pressure.…”

Section: High‐pressure Processingmentioning

confidence: 99%

Toward a Philosophy and Theory of Volumetric Nonthermal Processing

Sastry

2016

Journal of Food Science

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Nonthermal processes for food preservation have been under intensive investigation for about the past quarter century, with varying degrees of success. We focus this discussion on two volumetrically acting nonthermal processes, high pressure processing (HPP) and pulsed electric fields (PEF), with emphasis on scientific understanding of each, and the research questions that need to be addressed for each to be more successful in the future. We discuss the character or "philosophy" of food preservation, with a question about the nature of the kill step(s), and the sensing challenges that need to be addressed. For HPP, key questions and needs center around whether its nonthermal effectiveness can be increased by increased pressures or pulsing, the theoretical treatment of rates of reaction as influenced by pressure, the assumption of uniform pressure distribution, and the need for (and difficulties involved in) in-situ measurement. For PEF, the questions include the rationale for pulsing, difficulties involved in continuous flow treatment chambers, the difference between electroporation theory and experimental observations, and the difficulties involved in in-situ measurement and monitoring of electric field distribution.

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Effects of pressure and temperature on the reactions of horseradish peroxidase with hydrogen cyanide and hydrogen peroxide

Cited by 12 publications

References 14 publications

Synthesis and Characterization of Dextran–Tyramine-Based H₂O₂-Sensitive Microgels

Synthesis and Characterization of Dextran–Tyramine-Based H₂O₂-Sensitive Microgels

Rigidifying a De Novo Enzyme Increases Activity and Induces a Negative Activation Heat Capacity

Toward a Philosophy and Theory of Volumetric Nonthermal Processing

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Effects of pressure and temperature on the reactions of horseradish peroxidase with hydrogen cyanide and hydrogen peroxide

Cited by 12 publications

References 14 publications

Synthesis and Characterization of Dextran–Tyramine-Based H2O2-Sensitive Microgels

Synthesis and Characterization of Dextran–Tyramine-Based H2O2-Sensitive Microgels

Rigidifying a De Novo Enzyme Increases Activity and Induces a Negative Activation Heat Capacity

Toward a Philosophy and Theory of Volumetric Nonthermal Processing

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Product

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Synthesis and Characterization of Dextran–Tyramine-Based H₂O₂-Sensitive Microgels

Synthesis and Characterization of Dextran–Tyramine-Based H₂O₂-Sensitive Microgels