Optimal daily dosing usually requires about 200 mcg, divided into the selenite, selenomethionine, and selenocysteine
forms of selenium.
Recently, a considerable incorporation of selenocysteine
(SeCys) in proteins of the yeast proteome despite the absence of the uracil-guanine-adenine codon was demonstrated (Bierla et al.
Additionally selenium is a part of selenocysteine
and selenomethionine proteins, the main amino acid constituent of these enzymes is selenocysteine
, located in the active sites?
EF1[alpha] is one of the most abundant proteins, and responsible for the delivery of all aminoacyl-tRNAs to the ribosome, aside from initiator and selenocysteine
tRNAs (Mateyak & Kinzy 2010).
This enzyme (which has a single selenocysteine
group at the active site) catalyses die conversion of thyroxine, the major hormone product of the thyroid gland to the more biologically-active hormone, trii-odothyronine (T3).
KEY WORDS: nanotoxicology, proliferation, selenium, selenocysteine
, silver nanoparticles, thioredoxin reductase.
Nematode selenoproteome: the use of the selenocysteine
insertion system to decode one codon in an animal genome?
Selenium as a causative factor for goitre formation has been explained by diminished activity of selenocysteine
enzymes in thyroid, notably glutathione peroxidase and deiodinase type-1 in selenium deficiency (29,30).
The team, led by Ohad Birk of the Ben-Gurion University, determined that the defect is associated with the production of the 21st amino acid, selenocysteine
(SEC), which leads to progressive brain atrophy.
thaliana plants expressing a selenocysteine
methyltransferase (SMTA) isolated from the Se hyperaccumulator, Astragalus bisculcatus, accumulated methylselenocysteine and contained up to eight-fold higher Se concentrations than the wild-type plants, when grown on a soil supplemented with selenite (Se[O.
High-selenium yeast contains several different natural anabolic and catabolic forms of organically-bound selenium in addition to SeMet, such as selenocysteine
, methylselenocysteine, and several other selenium compounds, all organically bound.
The content of other organic selenium compounds, including selenocysteine
, does not exceed 10%.