Some Information About Threonine
Some Information About Threonine
Threonine is one of two amino acids out of the twenty with two chiral centers. Threonine can exist in four possible stereoisomers with the following configurations: (2S,3R), (2R,3S), (2S,3S) and (2R,3R). However, the name L-threonine is used for one single enantiomer, (2S,3R)-2-amino-3-hydroxybutanoic acid. The second stereoisomer (2S,3S), which is rarely present in nature, is called L-allo-threonine. The two stereoisomers (2R,3S)- and (2R,3R)-2-amino-3-hydroxybutanoic acid are only of minor importance.
Threonine is metabolized in two ways:
It is converted to pyruvate via threonine dehydrogenase. An intermediate in this pathway can undergo thiolysis with CoA to produce acetyl-CoA and glycine.
In humans, it is converted to alpha-ketobutyrate in a less common pathway via the enzyme serine dehydratase, and thereby enters the pathway leading to succinyl-CoA.
Foods high in threonine include cottage cheese, poultry, fish, meat, lentils, and sesame seeds.
Racemic threonine can be prepared from crotonic acid by alpha-functionalization using mercury(II) acetate.
Threonine is metabolized in two ways:
It is converted to pyruvate via threonine dehydrogenase. An intermediate in this pathway can undergo thiolysis with CoA to produce acetyl-CoA and glycine.
In humans, it is converted to alpha-ketobutyrate in a less common pathway via the enzyme serine dehydratase, and thereby enters the pathway leading to succinyl-CoA.
Foods high in threonine include cottage cheese, poultry, fish, meat, lentils, and sesame seeds.
Racemic threonine can be prepared from crotonic acid by alpha-functionalization using mercury(II) acetate.