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Xie, Xianhong; Wang, Zhiyong; Wu, Dingquan; Song-Sheng, Qu; Wang, Cunxin

doi:10.1023/a:1022220723342

Cited by 3 publications

(1 citation statement)

References 20 publications

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“…Biocalorimetry has been used previously to measure the enzymatic action of laccases, and also to measure the biological degradation of wood (Wadsö et al, 2017). The action of the plant laccase from Rhus vernicifera on different small phenolic substrates has been measured using microcalorimetry (Wang et al, 2000;Wong & Yu, 1999;X. Y. Xie et al, 2002).…”

Section: Discussionmentioning

confidence: 99%

Isothermal titration calorimetric assessment of lignin conversion by laccases

Islam

Zhang

Tonin

et al. 2021

Biotech & Bioengineering

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Lignin valorization may offer a sustainable approach to achieve a chemical industry that is not completely dependent on fossil resources for the production of aromatics.However, lignin is a recalcitrant, heterogeneous, and complex polymeric compound for which only very few catalysts can act in a predictable and reproducible manner.Laccase is one of those catalysts and has often been referred to as an ideal "green" catalyst, as it is able to oxidize various linkages within lignin to release aromatic products, with the use of molecular oxygen and formation of water as the only side product. The extent and rate of laccase-catalyzed lignin conversion were measured using the label-free analytical technique isothermal titration calorimetry (ITC). IITC provides the molar enthalpy of the reaction, which reflects the extent of conversion and the time-dependent power trace, which reflects the rate of the reaction. Calorimetric assessment of the lignin conversion brought about by various fungal and bacterial laccases in the absence of mediators showed marked differences in the extent and rate of conversion for the different enzymes. Kraft lignin conversion by Trametes versicolor laccase followed Michaelis-Menten kinetics and was characterized by the following thermodynamic and kinetic parameters ΔH ITC = −(2.06 ± 0.06)•10 3 kJ mol −1 , K M = 6.6 ± 1.2 μM and V max = 0.30 ± 0.02 U/mg at 25°C and pH 6.5. We envision calorimetric techniques as important tools for the development of enzymatic lignin valorization strategies.

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Section: Discussionmentioning

confidence: 99%

Isothermal titration calorimetric assessment of lignin conversion by laccases

Islam

Zhang

Tonin

et al. 2021

Biotech & Bioengineering

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Thermokinetic study on the reversible competitive inhibition of bovine liver arginase

Xie

Wang

2004

Chin. J. Chem.

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A new thermokinetic reduced extent method for studying of the reversible Competitive inhibition of single substrate enzyme-catalyzed reactions was proposed in this paper. The reaction that arginase-catalyzed hydrolysis of L-arginine to L-ornithine and urea and the inhibition of this reaction by the product, L-ornithine, and exogenous L-lysine were studied at 37 ' C in 40 mmol-L-' sodium barbiturate-HC1 buffer solution (pH=9.4). Michealis constant K, for arginine and maximum velocity V, of the reaction were determined to be 5.14 mmol-L-' and 1.13X lo-' mmol-L-'=s-', respectively. The product inhibition constant Kp and inhibitory constant K, of L-lysine were determined to be 1.18 and 5.6 mmol*L-', respectively. All the results have better repeatability and self-consistency and are in agreement with literature values. This new method using more direct thermal information from the process would give more reliable kinetic information than the traditional initial rate method.

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Microcalorimetric studies on the non-competitive inhibition of bovine liver arginase

Xie

Wang

2004

Journal of Thermal Analysis and Calorimetry

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Untitled

Cited by 3 publications

References 20 publications

Isothermal titration calorimetric assessment of lignin conversion by laccases

Isothermal titration calorimetric assessment of lignin conversion by laccases

Thermokinetic study on the reversible competitive inhibition of bovine liver arginase

Microcalorimetric studies on the non-competitive inhibition of bovine liver arginase

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