Threonine

Some important facts about Threonine:
Threonine contains two chiral centers, so there are four possible stereoisomers of threonine, or two possible diastereomers of L-threonine. However, the name L-threonine is used for one single enantiomer, (2S,3R)-2-amino-3-hydroxybutanoic acid. The second diastereomer (2S,3S), which is rarely present in nature, is called L-allo-threonine. The threonine side chain can undergo O-linked glycosylation. Threonine can become phosphorylated through the action of a threonine kinase. In its phosphorylated form, it can be referred to as phosphothreonine.

Use of threonine:
1. It is required to help maintain the proper protein balance in the body, as well as it also helps in the formation of collagen and elastin in the skin.
2. Threonine is an important part of many proteins in the body and is necessary for the formation of tooth enamel.
3. It is further involved in liver functioning (including fighting fatty liver), lipotropic functions when combined with aspartic acid and methionine as well as assisting the immune system by helping the production of antibodies and promotes thymus growth and activity.
4. Threonine is useful in the stabilization of blood sugar because it can be converted into glucose in the liver by the process of gluconeogenesis.
5. It also helps in the recovery after the injury. One study has shown that a cream containing cysteine, glycine and DL-threonine may help reduce the pain and decrease healing time of leg ulcers due to poor circulation.
6. The role of threonine in the functioning of the nervous system is highlighted by the body's increased demand for this amino acid during times of stress. It has been used as a supplement to help alleviate anxiety and some cases of depression.
7. Other nutrients are also better absorbed when threonine is present, and it has also been used as part treatment of mental health.

Deficiency symptoms of threonine:
1. Other nutrients are also better absorbed when threonine is present, and it has also been used as part treatment of mental health. In humans, deficiency may result in irritability and a generally difficult personality.

Symptoms of high intake:
No symptoms of high intake are known. People with kidney disease or liver disease should consult their doctor before taking threonine.

Daily requirement:
Therapeutic doses of threonine range from 300 to 1,200 mg per day. These doses are recommended to complete the deficiency in the diet. Higher doses must be taken under medical supervision as it may result in toxicity.

Other important facts :
Serum threonine concentration was determined during the first month of life in 163 low birth weight infants fed on human milk, various adapted formulae, or total parenteral nutrition. On the pooled data, a significant positive relationship was found between the serum threonine concentration and threonine intake. However, the increase of the serum threonine level is more marked in the infants with the lowest actual gestational age; with a high threonine intake, the most premature infants have serum threonine levels twice as high (58.1 vs 31.7 microM/dl) as term infants. Therefore, threonine metabolism seems to be impeded in preterm infants. Considering the cord blood concentration of threonine (26.8 +/- 5.1 microM/dl) and the possible hazardous effect of hyperthreoninemia, it is suggested that threonine intake should not exceed 1200 microM (143 mg)/kg bodyweight/day in premature infants and that the amino acid composition of the diet should probably be modified in order to satisfy their protein requirement.

Sources of threonine:
Foods high in threonine include:
..Cottage cheese (dry) 2,000 mg/cup
.. Cottage cheese 1,434 mg/cup
.. Fish & other seafood 800-6,500 mg/lb
.. Meats 1,000-4,500 mg/lb
.. Poultry 2,000-4,000 mg/lb
.. Peanuts, roasted w skin 2,000 mg/cup
.. Sesame seeds 1,500 mg/cup
.. Dry, whole lentils 1,750 mg/cup