Homocitric acid

Homocitric Acid

Chemical structure of homocitric acid

Homocitric acid is an organic compound that is structurally similar to citric acid, with the addition of an extra methylene group. It is a tricarboxylic acid and plays a role in the metabolism of certain organisms, particularly in the biosynthesis of lysine in some fungi and bacteria.

Structure and Properties

Homocitric acid is characterized by its three carboxyl groups and a hydroxyl group, making it a polyfunctional acid. The presence of these functional groups allows it to participate in various chemical reactions, including esterification and amide formation.

The chemical formula of homocitric acid is C7H10O7, and it has a molar mass of 206.15 g/mol. The additional methylene group compared to citric acid gives it slightly different chemical properties, affecting its solubility and reactivity.

Biological Role

In certain microorganisms, homocitric acid is an intermediate in the lysine biosynthesis pathway. This pathway is known as the _-aminoadipate pathway, which is distinct from the diaminopimelate pathway found in most bacteria and plants.

Homocitric acid is synthesized from acetyl-CoA and _-ketoglutarate in a reaction catalyzed by the enzyme homocitrate synthase. This reaction is analogous to the synthesis of citric acid in the citric acid cycle, highlighting the evolutionary relationship between these metabolic pathways.

Industrial and Research Applications

While homocitric acid itself is not widely used in industry, its role in lysine biosynthesis makes it of interest in biotechnology and metabolic engineering. Understanding and manipulating the pathways involving homocitric acid can lead to improved production of lysine, an essential amino acid used in animal feed and human nutrition.

Related Compounds

Homocitric acid is related to several other important biological compounds, including:

• Citric acid - a key intermediate in the citric acid cycle.
• Isocitric acid - an isomer of citric acid involved in the citric acid cycle.
• _-Ketoglutarate - a precursor in the synthesis of homocitric acid.

See Also

• Lysine biosynthesis
• Tricarboxylic acid
• Metabolic pathways

Related Pages

• Citric acid cycle
• Amino acid synthesis
• Biotechnology