Mark Haynes questioned about selenium and glutathione peroxidase. While the
glutathione molecule doesn't have any selenium atoms, the glutathione
peroxidase molecule does. No selenium, no glutathione peroxidase. More
recently it was discovered that the enzyme that converts the thyroid
hormone T4 to T3 by removing an iodine atom also has a selenium atom. Thus
no selenium, no conversion of T4 to T3 and you get hypothyroidism. The
benefit with regard to HIV and possibly with regard to cancer has to do with
the selenium analogs of the sulfur-containing amino acids. Selenocysteine
is identical to cysteine but with selenium replacing the sulfur atom. The
same substitution is true of selenomethionine.
Regards, Ralph L. Samson
