6VPD

Crystal structure of Trgpx in apo form

Summary for 6VPD

• Entry DOI: 10.2210/pdb6vpd/pdb
• Descriptor: Glutathione peroxidase (2 entities in total)
• Functional Keywords: glutathione peroxidase, oxidoreductase
• Biological source: Hypocrea jecorina (strain QM6a)
• Total number of polymer chains: 2
• Total formula weight: 44394.61

Authors

Adriani, P.P.,De Oliveira, G.S.,Paiva, F.C.R.,Dias, M.V.B.,Chambergo, F.S. (deposition date: 2020-02-03, release date: 2020-12-16, Last modification date: 2023-10-11)

Primary citation

Adriani, P.P.,de Paiva, F.C.R.,de Oliveira, G.S.,Leite, A.C.,Sanches, A.S.,Lopes, A.R.,Dias, M.V.B.,Chambergo, F.S.
Structural and functional characterization of the glutathione peroxidase-like thioredoxin peroxidase from the fungus Trichoderma reesei.
Int.J.Biol.Macromol., 167:93-100, 2020

PubMed 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 HO and t-BOOH, respectively, and no activity was observed when glutathione was used. These results indicated that TrGPx is a thioredoxin peroxidase and hydrolyses HO better than t-BOOH. TrGPx kinetic parameters using a pyrogallol assay resulted at K = 11.7 mM V = 10.9 IU/μg TrGPx, k = 19 s and a catalytic efficiency of 1.6 mM s to HO 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.

PubMed: 33259843
DOI: 10.1016/j.ijbiomac.2020.11.179

Experimental method

X-RAY DIFFRACTION (2.603 Å)