Can Selenoenzymes Resist Electrophilic Modification? Evidence from Thioredoxin Reductase and a Mutant Containing α-Methylselenocysteine.

ABSTRACT: Selenocysteine (Sec) is the 21st proteogenic amino acid in the genetic code. Incorporation of Sec into proteins is a complex and bioenergetically costly process that evokes the following question: "Why did nature choose selenium?" An answer that has emerged over the past decade is that Sec confers resistance to irreversible oxidative inactivation by reactive oxygen species. Here, we explore the question of whether this concept can be broadened to include resistance to reactive electrophilic species (RES) because oxygen and related compounds are merely a subset of RES. To test this hypothesis, we inactivated mammalian thioredoxin reductase (Sec-TrxR), a mutant containing α-methylselenocysteine [(αMe)Sec-TrxR], and a cysteine ortholog TrxR (Cys-TrxR) with various electrophiles, including acr

SUBMITTER: Ste Marie EJ 

PROVIDER: S-EPMC7509987 | biostudies-literature | 2020 Sep

REPOSITORIES: biostudies-literature