threonine metabolic process

Definition

Target type: biologicalprocess

The chemical reactions and pathways involving threonine (2-amino-3-hydroxybutyric acid), a polar, uncharged, essential amino acid found in peptide linkage in proteins. [GOC:jl, ISBN:0198506732]

Threonine metabolism is a crucial biological process involving the synthesis, degradation, and utilization of the amino acid threonine. This process is essential for various cellular functions, including protein synthesis, energy production, and the synthesis of other important molecules.

**Threonine Synthesis:**

* Threonine is synthesized from the amino acid aspartic acid through a series of enzymatic reactions.
* The first step involves the conversion of aspartic acid to aspartate semialdehyde by the enzyme aspartate kinase.
* Aspartate semialdehyde is then reduced to homoserine by the enzyme homoserine dehydrogenase.
* Finally, homoserine is converted to threonine by the enzyme threonine synthase.

**Threonine Degradation:**

* Threonine is degraded through a pathway involving the enzyme threonine dehydratase.
* Threonine dehydratase catalyzes the removal of a water molecule from threonine, producing α-ketobutyrate and ammonia.
* α-ketobutyrate can then be further metabolized to propionyl-CoA, which enters the citric acid cycle for energy production.

**Threonine Utilization:**

* Threonine is a key precursor for the synthesis of other amino acids, including glycine and serine.
* It is also involved in the synthesis of the neurotransmitter GABA (gamma-aminobutyric acid) and the immune system component, glutathione.
* Threonine plays a role in the regulation of gene expression and cell growth.

**Metabolic Regulation:**

* The metabolism of threonine is tightly regulated to maintain cellular homeostasis.
* Feedback inhibition mechanisms control the activity of enzymes involved in threonine synthesis and degradation.
* Dietary intake of threonine and the availability of other amino acids also influence threonine metabolism.

**Clinical Significance:**

* Threonine deficiency is rare but can lead to various health problems, including growth retardation and immune dysfunction.
* Certain genetic disorders affecting threonine metabolism can result in neurological and developmental abnormalities.
* Threonine supplementation has been investigated for its potential benefits in treating various conditions, such as anxiety and depression.

**Overall, threonine metabolism is a complex and vital biological process that plays a critical role in maintaining cellular function and overall health.**'
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Proteins (2)

Compounds (2)