Por favor, use este identificador para citar o enlazar a este item:
http://hdl.handle.net/10261/10247
COMPARTIR / EXPORTAR:
SHARE CORE BASE | |
Visualizar otros formatos: MARC | Dublin Core | RDF | ORE | MODS | METS | DIDL | DATACITE | |
Título: | Protein radicals in fungal versatile peroxidase: Catalytic tryptophan radical in both Compound-I and Compound-II and studies on W164Y, W164H and W164S variants |
Otros títulos: | Protein Radicals in Versatile Peroxidase [Running title] | Autor: | Ruiz-Dueñas, F. J. CSIC ORCID ; Pogni, Rebecca; Morales, María CSIC; Giansanti, Stefania; Maté, María J. CSIC; Romero, Antonio CSIC ORCID ; Martínez, María Jesús CSIC ORCID ; Basosi, Riccardo; Martínez, Ángel T. CSIC ORCID | Fecha de publicación: | 20-mar-2009 | Editor: | American Society for Biochemistry and Molecular Biology | Citación: | J Biol Chem. 284(12): 7986–7994 (2009) | Resumen: | Lignin-degrading peroxidases, a group of biotechnologically-interesting enzymes,?oxidize high redox-potential aromatics via an exposed protein radical. Low-temperature EPR of Pleurotus eryngii versatile peroxidase (VP) revealed, for the first time in a fungal peroxidase, the presence of a tryptophanyl radical in both the two-electron (VPI) and one-electron (VPII) activated forms of the enzyme. Site-directed mutagenesis was used to substitute this tryptophan (Trp164) by tyrosine and histidine residues. No changes in the crystal structure were observed indicating that the modified behavior was due exclusively to the mutations introduced. EPR revealed the formation of tyrosyl radicals in both VPI and VPII of the W164Y variant. However, no protein radical was detected in the W164H variant, whose VPI spectrum indicated a porphyrin radical identical to that of the inactive W164S. Stopped-flow spectrophotometry showed that the W164Y mutation reduced 10-fold the apparent second-order rate constant for VPI reduction (k2app) by veratryl alcohol (VA), compared with over 50-fold reduction in W164S, revealing some catalytic activity of the tyrosine radical. Its first-order rate constant (k2) was more affected than the dissociation constant (KD2). Moreover, VPII reduction by VA was impaired by the above mutations revealing that the Trp164 radical was involved in catalysis by both VPI and VPII. The low first-order rate constant (k3) values were similar for the W164Y, W164H and W164S variants, indicating that the tyrosyl radical in VPII was not able to oxidize VA (in contrast with that observed for VPI). VPII self-reduction was also suppressed revealing that Trp164 is involved in this autocatalytic process. | Descripción: | 9 p.-4 fig.-4 tab. | Versión del editor: | http://dx.doi.org/10.1074/jbc.M808069200 | URI: | 10261/10247 | DOI: | 10.1074/jbc.M808069200 | ISSN: | 0021-9258 | E-ISSN: | 1083-351X |
Aparece en las colecciones: | (CIB) Artículos |
Ficheros en este ítem:
Fichero | Descripción | Tamaño | Formato | |
---|---|---|---|---|
Protein radicals_2009.pdf | 433,22 kB | Adobe PDF | Visualizar/Abrir |
CORE Recommender
PubMed Central
Citations
15
checked on 14-mar-2024
SCOPUSTM
Citations
58
checked on 14-mar-2024
WEB OF SCIENCETM
Citations
55
checked on 26-feb-2024
Page view(s)
381
checked on 18-mar-2024
Download(s)
210
checked on 18-mar-2024
Google ScholarTM
Check
Altmetric
Altmetric
Artículos relacionados:
NOTA: Los ítems de Digital.CSIC están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.