Selenoproteins Classification and Functions

Table 1 lists the selenoproteins that have been unequivocally identified in mammals, together with a summary of their main locations and known functions. Of the known glutathione peroxidases, three are tetramers and one (the phospholipid hydroperoxide-specific peroxidase) is monomeric in its quaternary structure. It appears to be this class of enzymatic activity that is critical for the action of selenoproteins in maintaining immune function, and indeed, glutathione peroxidase type I knockout mice are susceptible to viral mutation and increased viral virulence, as are selenium-deficient ones. Several other selenoproteins listed in Table 1 also have antioxidant functions and activities. Reaction of glutathione peroxidase with peroxides yields selenic or seleninic acid at the active site of the enzyme, which is recycled by glutathione.

The three thioredoxin reductases act in conjunction with the sulfur protein thioredoxin and with NADPH to bind key transcription factors to DNA. The iodothyronine deiodinases modulate the thyroid hormones, helping to ensure an optimal supply of the

Table 1 Selenoprotein description and functions

Selenoprotein

Molecular description

Function

Glutathione peroxidases (GPx)

Was this article helpful?

0 0
Diet Tweak System

Diet Tweak System

Trying To Lose Weight Can Be Tough. But... Not Losing Weight and Gaining What You Lost Back, Sucks. If you've ever felt that no matter what you do to lose weight nothing seems to work. If you've ever felt that there has got to be some kind of a system or way to lose weight...but just have not found it yet.

Get My Free Ebook


Post a comment