Structural and functional characterization of the glutathione peroxidase-like thioredoxin peroxidase from the fungus Trichoderma reesei
Int J Biol Macromol, v. 167, p. 93-100, jan. 2021
Artigo
em Inglês
| Sec. Est. Saúde SP, SESSP-IBPROD, Sec. Est. Saúde SP
| ID: bud-3507
Biblioteca responsável:
BR78.1
ABSTRACT
Glutathione peroxidases (GPx) are a family of enzymes with the ability to reduce organic and inorganic hydroperoxides to the corresponding alcohols using glutathione or thioredoxin as an electron donor. Here, we report the functional and structural characterization of a GPx identified in Trichoderma reesei (TrGPx). TrGPx was recombinantly expressed in a bacterial host and purified using affinity. Using a thioredoxin coupled assay, TrGPx exhibited activity of 28 U and 12.5 U in the presence of the substrates H2O2 and t-BOOH, respectively, and no activity was observed when glutathione was used. These results indicated that TrGPx is a thioredoxin peroxidase and hydrolyses H2O2 better than t-BOOH. TrGPx kinetic parameters using a pyrogallol assay resulted at Kmapp = 11.7 mM, Vmaxapp = 10.9 IU/μg TrGPx, kcat = 19 s−1 and a catalytic efficiency of 1.6 mM−1 s−1 to H2O2 as substrate. Besides that, TrGPx demonstrated an optimum pH ranging from 9.0–12.0 and a half-life of 36 min at 80 °C. TrGPx 3D-structure was obtained in a reduced state and non-catalytic conformation. The overall fold is similar to the other phospholipid-hydroperoxide glutathione peroxidases. These data contribute to understand the antioxidant mechanism in fungi and provide information for using antioxidant enzymes in biotechnological applications.
Texto completo:
Disponível
Coleções:
Bases de dados nacionais
/
Brasil
Base de dados:
Sec. Est. Saúde SP
/
SESSP-IBPROD
Idioma:
Inglês
Revista:
Int J Biol Macromol
Ano de publicação:
2021
Tipo de documento:
Artigo