Optimized oxidoreductases for medium and large scale industrial biotransformations
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Dr Marta Pérez-Boada
E-mail: MPBoada@cib.csic.es
Consejo Superior de Investigaciones Científicas (CSIC)
Biological Research Centre (CIB)
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publications
Total records: 126
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[ 2019 ] Linde D, Ayuso-Fernández I, Ruiz-Dueñas FJ, Martínez AT Different fungal peroxidases oxidize nitrophenols at a surface catalytic tryptophan Arch. Biochem. Biophys., 668: 23-28
[ 2019 ] Serrano A, Sancho F, Viña-Gonzalez J, Carro J, Alcalde M, Guallar V, Martínez AT Switching the substrate preference of fungal aryl-alcohol oxidase: towards stereoselective oxidation of secondary benzyl alcohols Catal. Sci. Technol., doi: 10.1039/C8CY02447B
[ 2019 ] Viña-Gonzalez J, Jimenez-Lalana D, Sancho F, Serrano A, Martínez AT, Guallar V, Alcalde M Structure‐Guided Evolution of Aryl Alcohol Oxidase from Pleurotus eryngii for the Selective Oxidation of Secondary Benzyl Alcohols Adv. Synth. Catal., 361: 2514-2525
[ 2018 ] Carro J, Fernandez-Fueyo E, Fernández-Alonso C, Cañada J, Ullrich R, Hofrichter M, Alcalde M, Ferreira P, Martínez AT Self-sustained enzymatic cascade for the production of 2,5-furandicarboxylic acid from 5-methoxymethylfurfural Biotechnol. Biofuels, 11: 86-96
[ 2018 ] Carro J, Ferreira P, Martínez AT, Gadda G Stepwise Hydrogen Atom and Proton Transfers in Dioxygen Reduction by Aryl-Alcohol Oxidase Biochemistry, doi: 10.1021/acs.biochem.8b00106
[ 2018 ] Ewing TA, Kühn J, Segarra S, Tortajada M, Zuhse R, van Berkel WJ Multigram Scale Enzymatic Synthesis of (R)‐1‐(4′‐Hydroxyphenyl)ethanol Using Vanillyl Alcohol Oxidase Adv. Synth. Catal., 360: 2370-2376
year2016
Role of surface tryptophan for peroxidase oxidation of nonphenolic lignin
Saez-Jimenez V, Rencoret J, Rodríguez-Carvajal MA, Gutiérrez A, Ruiz-Dueñas FJ, Martínez AT
Biotechnol. Biofuels, 9: 198-211

Background

Despite claims as key enzymes in enzymatic delignification, very scarce information on the reaction rates between the ligninolytic versatile peroxidase (VP) and lignin peroxidase (LiP) and the lignin polymer is available, due to methodological difficulties related to lignin heterogeneity and low solubility.

Results

Two water-soluble sulfonated lignins (from Picea abies and Eucalyptus grandis) were chemically characterized and used to estimate single electron-transfer rates to the H2O2-activated Pleurotus eryngii VP (native enzyme and mutated variant) transient states (compounds I and II bearing two- and one-electron deficiencies, respectively). When the rate-limiting reduction of compound II was quantified by stopped-flow rapid spectrophotometry, from fourfold (softwood lignin) to over 100-fold (hardwood lignin) lower electron-transfer efficiencies (k 3app values) were observed for the W164S variant at surface Trp164, compared with the native VP. These lignosulfonates have ~20–30 % phenolic units, which could be responsible for the observed residual activity. Therefore, methylated (and acetylated) samples were used in new stopped-flow experiments, where negligible electron transfer to the W164S compound II was found. This revealed that the residual reduction of W164S compound II by native lignin was due to its phenolic moiety. Since both native lignins have a relatively similar phenolic moiety, the higher W164S activity on the softwood lignin could be due to easier access of its mono-methoxylated units for direct oxidation at the heme channel in the absence of the catalytic tryptophan. Moreover, the lower electron transfer rates from the derivatized lignosulfonates to native VP suggest that peroxidase attack starts at the phenolic lignin moiety. In agreement with the transient-state kinetic data, very low structural modification of lignin, as revealed by size-exclusion chromatography and two-dimensional nuclear magnetic resonance, was obtained during steady-state treatment (up to 24 h) of native lignosulfonates with the W164S variant compared with native VP and, more importantly, this activity disappeared when nonphenolic lignosulfonates were used.

Conclusions

We demonstrate for the first time that the surface tryptophan conserved in most LiPs and VPs (Trp164 of P. eryngii VPL) is strictly required for oxidation of the nonphenolic moiety, which represents the major and more recalcitrant part of the lignin polymer.

Official webpage of indox [ industrialoxidoreductases ]. Optimized oxidoreductases for medium and large scale industrial biotransformations. This project has received funding from the European Union’s Seventh Framework Programme for research, technological development and demonstration under Grant Agreement nº: FP7-KBBE-2013-7-613549. © indox 2013. Developed by garcíarincón