Effect of Methylmercury Binding on the Peroxide-Reducing Potential of Cysteine and Selenocysteine.

ABSTRACT: Methylmercury (CH₃Hg⁺) binding to catalytically fundamental cysteine and selenocysteine of peroxide-reducing enzymes has long been postulated as the origin of its toxicological activity. Only very recently, CH₃Hg⁺ binding to the selenocysteine of thioredoxin reductase has been directly observed [Pickering, I. J. Inorg. Chem., 2020, 59, 2711-2718], but the precise influence of the toxicant on the peroxide-reducing potential of such a residue has never been investigated. In this work, we employ state-of-the-art density functional theory calculations to study the reactivity of molecular models of the free and toxified enzymes. Trends in activation energies are discussed with attention to the biological consequences and are rationalized within

SUBMITTER: Madabeni A 

PROVIDER: S-EPMC8763373 | biostudies-literature | 2021 Apr

REPOSITORIES: biostudies-literature