What is Threonine? Brief Explanation & Example

Threonine is an amino acid. Amino acids are the building blocks the body uses to make proteins. Threonine is used to treat various nervous system disorders including spinal spasticity, multiple sclerosis, familial spastic paraparesis, and amyotrophic lateral sclerosis (ALS, Lou Gehrig’s disease).

Threonine sidechains are often hydrogen bonded; the most common small motifs formed are based on interactions with serine: ST turns, ST motifs (often at the beginning of alpha helices), and ST staples (usually at the middle of alpha-helices).

Threonine Structure

Threonine (symbol Thr or T) is an amino acid that is used in the biosynthesis of proteins. It contains an α-amino group (which is in the protonated −NH+3 form under biological conditions), a carboxyl group (which is in the deprotonated −COO− form under biological conditions), and a side chain containing a hydroxyl group, making it a polar, uncharged amino acid. It is essential in humans, meaning the body cannot synthesize it: it must be obtained from the diet. Threonine is synthesized from aspartate in bacteria such as E. coli. It is encoded by all the codons starting AC (ACT, ACC, ACA, and ACG).



L-threonine is an optically active form of threonine having L-configuration. It has a role as a nutraceutical, a micronutrient, a Saccharomyces cerevisiae metabolite, a plant metabolite, an Escherichia coli metabolite, a human metabolite, an algal metabolite, and a mouse metabolite. It is an aspartate family amino acid, a proteinogenic amino acid, a threonine, and an L-alpha-amino acid. It is a conjugate base of an L-threoninium. It is the conjugate acid of a L-threoninate. It is an enantiomer of a D-threonine. It is a tautomer of a L-threonine zwitterion.

Threonine Abbreviation One Letter Code

Full Name Abbreviation (3 Letter) Abbreviation (1 Letter)
Threonine Thr T

Serine/Threonine Kinase

Akt is a serine/threonine-specific protein kinase of which there are three isoforms; Akt1, Akt2, and Akt3. Endogenous H2O2 has been shown to increase Akt activation in numerous cell types (Ushio-Fukai et al., 1999). This activation is dependent on the upstream production of lipid products by PI3K (Kwon et al., 2004). H2O2 activation of Akt is also mediated by Src kinase (Esposito et al., 2003). Furthermore, EGFR-dependent activation of Akt enhances cell survival during H2O2-induced apoptosis (Wang et al., 2000). More recent studies suggest that the effects of oxidation on Akt are isoform-specific.

Wani et al. identified, in response to PDGF stimulation, the direct oxidation of Cys124 in the linker domain and of Cys297 and Cys311 in the kinase domain activation loop of the Akt2 isoform. This oxidative modification correlated with a decrease in Akt2 kinase activity while in contrast Akt1 and Akt3 remained active. Unlike Akt2, Akt1, and Akt3 do not have cysteine analogs corresponding to Cys124. This is a valuable example of the degree of target specificity that can be achieved through redox-signaling.

Threonine Amino Acid

Amino Acids form the proteins that in turn form muscle tissue and increase fat metabolism. Look in the cupboard of just about any serious athlete, and you’ll likely find some kind of amino acid supplement or protein drink designed to help them increase strength, build muscle tissue, or otherwise enhance their athletic performance. However, amino acids are not just important to those who wish to “bulk up.” Without amino acids, all cellular development, respiration, or renewal would cease.

There are just 22 amino acids, but without them, all of the metabolic processes necessary to spark and sustain animal life would simply not be possible. Long chains of amino acids combine to form up to 55,000 different proteins, and each protein is used to produce the enzymes, neurotransmitters, and hormones that support normal growth and functioning of all bodily organs, including the heart, brain, liver, kidneys, and sex organs.

There are two types of amino acids: essential amino acids and nonessential amino acids. Essential amino acids cannot be manufactured in the body (you get them by eating foods that contain protein), and nonessential amino acids are manufactured within the body by combining two or more essential amino acids. However, adequate amounts of dietary protein are needed to form all 22 amino acids—if you don’t get enough protein your body won’t have the 9 essential amino acids it needs to make up the other 13 nonessential amino acids.

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