Versatile peroxidase (VP) from Bjerkandera adusta is an enzyme able to oxidize bulky and high-redox substrates trough a Long-Range Electron Transfer (LRET) pathway. In this study, the introduction of radical-forming aromatic amino acids by chemical modification of the protein surface was performed, and the catalytic implications of these additional surface active-sites on the oxidation of 2,6-dimethylphenol, Mn2+ and Remazol Brilliant Blue R (RBBR) were determined. These three different substrates are oxidized in different active-sites of enzyme molecule, of which the high redox RBBR the only one that is transformed by an external radical formed on the protein surface. Both catalytic constants kcat and KM were significantly affected by the chemical modifications. Tryptophan- and tyrosine-modified VP showed higher catalytic transformation than the unmodified enzyme for RBBR, while the Mn2+ oxidation was significantly reduced by all chemical modifications. Electron Paramagnetic Resonance studies demonstrated the formation of additional protein-based radicals after the chemical modification with radical-forming amino acids. In addition, the catalytic rate of the LRET-mediated transformation showed a good correlation with the ionization energy of the additional amino acid on the protein surface.

Sánchez-Alejandro, F., Baratto, M.C., Basosi, R., Graeve, O., Vazquez-Duhalt, R. (2019). Addition of new catalytic sites on the surface of versatile peroxidase for enhancement of LRET catalysis. ENZYME AND MICROBIAL TECHNOLOGY, 131, 1-6 [10.1016/j.enzmictec.2019.109429].

Addition of new catalytic sites on the surface of versatile peroxidase for enhancement of LRET catalysis

Maria Camilla Baratto;Riccardo Basosi;
2019-01-01

Abstract

Versatile peroxidase (VP) from Bjerkandera adusta is an enzyme able to oxidize bulky and high-redox substrates trough a Long-Range Electron Transfer (LRET) pathway. In this study, the introduction of radical-forming aromatic amino acids by chemical modification of the protein surface was performed, and the catalytic implications of these additional surface active-sites on the oxidation of 2,6-dimethylphenol, Mn2+ and Remazol Brilliant Blue R (RBBR) were determined. These three different substrates are oxidized in different active-sites of enzyme molecule, of which the high redox RBBR the only one that is transformed by an external radical formed on the protein surface. Both catalytic constants kcat and KM were significantly affected by the chemical modifications. Tryptophan- and tyrosine-modified VP showed higher catalytic transformation than the unmodified enzyme for RBBR, while the Mn2+ oxidation was significantly reduced by all chemical modifications. Electron Paramagnetic Resonance studies demonstrated the formation of additional protein-based radicals after the chemical modification with radical-forming amino acids. In addition, the catalytic rate of the LRET-mediated transformation showed a good correlation with the ionization energy of the additional amino acid on the protein surface.
2019
Sánchez-Alejandro, F., Baratto, M.C., Basosi, R., Graeve, O., Vazquez-Duhalt, R. (2019). Addition of new catalytic sites on the surface of versatile peroxidase for enhancement of LRET catalysis. ENZYME AND MICROBIAL TECHNOLOGY, 131, 1-6 [10.1016/j.enzmictec.2019.109429].
File in questo prodotto:
File Dimensione Formato  
EnzymeMicrobialTechnology_2019.pdf

non disponibili

Tipologia: PDF editoriale
Licenza: NON PUBBLICO - Accesso privato/ristretto
Dimensione 856.45 kB
Formato Adobe PDF
856.45 kB Adobe PDF   Visualizza/Apri   Richiedi una copia

I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.

Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11365/1080902