Homoserine

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HomoserineBiosyn

Homoserine biosyntheses

Homoserine is a non-proteinogenic amino acid with the chemical formula C₄H₉NO₃. It is an intermediate in the biosynthesis of methionine, threonine, and isoleucine.

Structure and Properties

Homoserine is structurally similar to the amino acid serine, but it has an additional methylene group. It is classified as a hydroxy acid due to the presence of a hydroxyl group (-OH) attached to the carbon chain. The compound exists in two enantiomeric forms, D-homoserine and L-homoserine, with L-homoserine being the biologically active form.

Biosynthesis

Homoserine is synthesized from aspartic acid via a series of enzymatic reactions. The pathway begins with the phosphorylation of aspartic acid to form aspartyl-phosphate, which is then reduced to form aspartate-semialdehyde. This intermediate is subsequently converted to homoserine by the enzyme homoserine dehydrogenase.

Role in Metabolism

Homoserine serves as a precursor in the biosynthetic pathways of several essential amino acids:

• Methionine: Homoserine is converted to O-phosphohomoserine, which is then transformed into homocysteine and subsequently methionine.
• Threonine: Homoserine is phosphorylated to form O-phosphohomoserine, which is then converted to threonine by threonine synthase.
• Isoleucine: Homoserine is involved in the biosynthesis of isoleucine through a series of reactions that also involve threonine.

Industrial and Biotechnological Applications

Homoserine and its derivatives are used in various industrial and biotechnological applications. It is a key intermediate in the production of amino acids and other compounds through microbial fermentation processes. Additionally, homoserine can be used as a building block in the synthesis of pharmaceuticals and other bioactive molecules.

Related Pages

• Amino acid
• Biosynthesis
• Methionine
• Threonine
• Isoleucine
• Aspartic acid
• Enzyme
• Metabolism

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