TY - JOUR
T1 - A dual attack on the peroxide bond. The common principle of peroxidatic cysteine or selenocysteine residues
AU - Dalla Tiezza, M.
AU - Bickelhaupt, F. M.
AU - Flohé, L.
AU - Maiorino, M.
AU - Ursini, F.
AU - Orian, L.
PY - 2020/7
Y1 - 2020/7
N2 - The (seleno)cysteine residues in some protein families react with hydroperoxides with rate constants far beyond those of fully dissociated low molecular weight thiol or selenol compounds. In case of the glutathione peroxidases, we could demonstrate that high rate constants are achieved by a proton transfer from the chalcogenol to a residue of the active site [Orian et al. Free Radic. Biol. Med. 87 (2015)]. We extended this study to three more protein families (OxyR, GAPDH and Prx). According to DFT calculations, a proton transfer from the active site chalcogenol to a residue within the active site is a prerequisite for both, creating a chalcogenolate that attacks one oxygen of the hydroperoxide substrate and combining the delocalized proton with the remaining OH or OR, respectively, to create an ideal leaving group. The “parking postions” of the delocalized proton differ between the protein families. It is the ring nitrogen of tryptophan in GPx, a histidine in GAPDH and OxyR and a threonine in Prx. The basic principle, however, is common to all four families of proteins. We, thus, conclude that the principle outlined in this investigation offers a convincing explanation for how a cysteine residue can become peroxidatic.
AB - The (seleno)cysteine residues in some protein families react with hydroperoxides with rate constants far beyond those of fully dissociated low molecular weight thiol or selenol compounds. In case of the glutathione peroxidases, we could demonstrate that high rate constants are achieved by a proton transfer from the chalcogenol to a residue of the active site [Orian et al. Free Radic. Biol. Med. 87 (2015)]. We extended this study to three more protein families (OxyR, GAPDH and Prx). According to DFT calculations, a proton transfer from the active site chalcogenol to a residue within the active site is a prerequisite for both, creating a chalcogenolate that attacks one oxygen of the hydroperoxide substrate and combining the delocalized proton with the remaining OH or OR, respectively, to create an ideal leaving group. The “parking postions” of the delocalized proton differ between the protein families. It is the ring nitrogen of tryptophan in GPx, a histidine in GAPDH and OxyR and a threonine in Prx. The basic principle, however, is common to all four families of proteins. We, thus, conclude that the principle outlined in this investigation offers a convincing explanation for how a cysteine residue can become peroxidatic.
KW - Density functional theory
KW - DFT
KW - GAPDH
KW - Glyceroaldehyde dehydrogenase
KW - Oxidative stress regulator
KW - OxyR
KW - Peroxidatic cysteine
KW - Peroxiredoxin
KW - Reaction mechanism
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U2 - 10.1016/j.redox.2020.101540
DO - 10.1016/j.redox.2020.101540
M3 - Article
AN - SCOPUS:85084436513
VL - 34
SP - 1
EP - 9
JO - Redox Biology
JF - Redox Biology
SN - 2213-2317
M1 - 101540
ER -