Adriani, Patricia P.
de Paiva, Fernanda C. R.
de Oliveira, Gabriel S.
Leite, Amanda C.
Sanches, Adriana S.
Lopes, Adriana Rios
Dias, Marcio V. B.
Chambergo, Felipe S.
Total Authors: 8
 Univ Sao Paulo, Escola Artes Ciencias & Humanidades, 1000 Arlindo Bettio Ave, BR-03828000 Sao Paulo - Brazil
 Univ Sao Paulo, Inst Ciencias Biomed, Dept Microbiol, 1374 Prof Lineu Prestes Ave, Sao Paulo - Brazil
 Inst Butantan, Lab Biochem, Av Vital Brasil 1500, Sao Paulo - Brazil
 Univ Warwick, Dept Chem, Gibbet Hill, Coventry CV4 7AL, W Midlands - England
Total Affiliations: 4
International Journal of Biological Macromolecules;
JAN 15 2021.
Web of Science Citations:
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 K-mapp = 11.7 mM, V-maxapp = 10.9 IU/mu g TrGPx, k(cat) = 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 degrees 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 antioxidantmechanism in fungi and provide information for using antioxidant enzymes in biotechnological applications. (C) 2020 Published by Elsevier B.V. (AU)