Selenocysteine Amino Acid Benefits

amino acids selenocysteine

Selenocysteine amino acid is the analog of cysteine having the same structure as that of cysteine. But here sulphur atom is replaced by selenium. It is the 21st amino acid found in the ribosome mediated protein synthesis. It is present in the number of enzymes like tetraidothyronine deiodinase, glutathione perxidase, thioredoxine reductase, glycine reductase, formate dehydrogenase and in hydrogenases. Proteins having more than one selenocysteine residues are called selenoprotein. There is no single free pool of selenocysteine amino acid that exists within cells to be used. So it means it is an essential amino acid which is needed to be provided through food.

Sources

Selenocysteine is found in proteins and in variety of foods of either animal origin or plant origin.

Animal origin: Selenocysteine animal sources are meat, poultry, chicken, egg, cheese fish, seafood and turkey.

Plant origin: Selenocysteine of plant origin contains wheat, oats, corn, rice, nuts especially of Brazil nuts, soybeans.

Selenocysteine is available in the food in the form of selenomethionine. In some foodstuff it occurs in the form of selenate.

Biosynthesis

The biosynthesis of this amino acid occurs on the tRNA which needs to be first acylated with serine and then is subsequently transformed into selenocysteine by an enzyme synthase that further utilizes selenophosphate in the form of selenium donor and the cofactor pyridoxal phosphate.

Functions

  • The important functions of selenocysteine in proteins are its anti –oxidant activity. This is due to its lower pKa and higher reduction potential.
  •  It is also used in the preparation of variety of vitamins and lots of other supplements.
  • It is also fortified with livestock feeds.
  • Our body utilizes selenocysteine to form selenium, which is believe to play important role in preventing mercury toxicity as well as enhance liver functions.
  • People deficient with selenium have lean body mass, prone to premature aging or to heart diseases.

Selenocystein is not coded for in the genetic code directly. It is encoded by the UAG codon in a very special way. UAG is a stop codon.

Related posts:

Amino Acids Found in Human DNA
There are twenty amino acids (AA) which have been found to occur in all proteins and for which genetic codon exits. Each of these has one or more g...
Isoleucine Amino Acid Benefits
Isoleucine is an essential amino acid so it needs to be provided by the food to our body. It has aliphatic side chain and is non polar. It is also h...
Lysine Amino Acid Benefits
Lysine is the amino acid with the basic side chain. It is an essential amino acid as it is not manufactured in our body so it needs to be supplied f...
Serine Amino Acid Benefits
Serine is the amino acid with uncharged polar side chain. It was isolated first from the silk protein named sericin in 1865. It is a non essential a...
Tyrosine Amino Acid Benefits
Tyrosine is the amino acid with aromatic side chain. It has hydroxyl group for H bonds and shows polarity. It is non-essential amino acid which mean...
Amino acid supplements good for your bra...
The human brain is a marvel of nature. It is more complex than any machine man has ever made. It performs tasks that seem impossibly difficult and ach...