MOLECULE

L-Threonine

Threonine, abbreviated Thr or T, is an essential amino acid in humans. It has a side chain containing a hydroxyl group, making it a polar, uncharged amino acid Threonine is catabolized in mammals largely (70-80%) by threonine dehydrogenase (EC 1.1.1.103) that oxidizes threonine to 2-amino-3-oxobutyrate (which forms glycine and acetyl CoA), and much less by threonine dehydratase (EC 4.2.1.16) that catabolizes threonine into 2-oxobutyrate and ammonia. It is highly concentrated in meat products, cottage cheese and wheat germ. L-Threonine is also found in Cannabis plants (PMID: 6991645). It is abundant in human plasma, particularly in newborns. The threonine content of most infant formulas currently on the market is approximately 20% higher than the threonine concentration in human milk. Premature infants fed these formulas have twice the plasma threonine concentrations of breast-fed infants. Increasing the threonine plasma concentrations leads to accumulation of threonine and glycine in the brain. Such accumulation affects the neurotransmitter balance which may have consequences for the brain development during early postnatal life. Thus, excessive threonine intake during infant feeding should be avoided (PMID: 9853925). Threonine is an immunostimulant which promotes the growth of thymus gland and probably promotes cell immune defense function. This amino acid has been useful in the treatment of genetic spasticity disorders and multiple sclerosis at a dose of 1 g per day. Severe deficiency of threonine causes neurological dysfunction and lameness in experimental animals