Propane-1,2,3-tricarboxylic acid, also known as tricarballylic acid, carballylic acid, and β-carboxyglutaric acid, is a

tricarboxylic acid A tricarboxylic acid is an organic carboxylic acid whose chemical structure contains three carboxyl functional groups (-COOH). The best-known example of a tricarboxylic acid is citric acid. Uses Citric acid cycle Citric acid, a type of tricar ...

. The compound is an inhibitor of the enzyme aconitase and therefore interferes with the

Krebs cycle The citric acid cycle (CAC)—also known as the Krebs cycle or the TCA cycle (tricarboxylic acid cycle)—is a series of chemical reactions to release stored energy through the oxidation of acetyl-CoA derived from carbohydrates, fats, and protein ...

Ester In chemistry, an ester is a compound derived from an oxoacid (organic or inorganic) in which at least one hydroxyl group () is replaced by an alkoxy group (), as in the substitution reaction of a carboxylic acid and an alcohol. Glycerides a ...

s of propane-1,2,3-tricarboxylic acid are found in natural products such as the

mycotoxin A mycotoxin (from the Greek μύκης , "fungus" and τοξίνη , "toxin") is a toxic secondary metabolite produced by organisms of kingdom Fungi and is capable of causing disease and death in both humans and other animals. The term 'mycotoxin' ...

fumonisin The fumonisins are a group of mycotoxins derived from ''Fusarium'' and their Liseola section. They have strong structural similarity to sphinganine, the backbone precursor of sphingolipids. More specifically, it can refer to: * Fumonisin B1 * Fum ...

s B1 and B2 and AAL toxin T_A, and in macrocyclic inhibitors of Ras farnesyl-protein transferase (FPTase) such as actinoplanic acid. Propane-1,2,3-tricarboxylic acid can be synthesized in two steps from

fumaric acid Fumaric acid is an organic compound with the formula HO2CCH=CHCO2H. A white solid, fumaric acid occurs widely in nature. It has a fruit-like taste and has been used as a food additive. Its E number is E297. The salts and esters are known as fu ...

Mechanism of the inhibition of aconitase

Image:Citrate wpmp.png, Image:Cis-Aconitate wpmp.png, Image:isocitric acid.svg, {{center,

Isocitric acid Isocitric acid is a structural isomer of citric acid. Since citric acid and isocitric acid are structural isomers, they share similar physical and chemical properties. Due to these similar properties, it is difficult to separate the isomers. Salts ...

Aconitase normally catalyses, via the intermediate aconitic acid, the interconversion of

citric acid Citric acid is an organic compound with the chemical formula HOC(CO2H)(CH2CO2H)2. It is a colorless weak organic acid. It occurs naturally in citrus fruits. In biochemistry, it is an intermediate in the citric acid cycle, which occurs in ...

into

isocitric acid Isocitric acid is a structural isomer of citric acid. Since citric acid and isocitric acid are structural isomers, they share similar physical and chemical properties. Due to these similar properties, it is difficult to separate the isomers. Salts ...

. Propane-1,2,3-tricarboxylic acid is well suited to bind to aconitase as it only lacks the hydroxide group in comparison to citric acid. However, the hydroxide group is essential to proceed from citric acid to aconitic acid, therefore the enzyme is not able to complete the reaction with propane-1,2,3-tricarboxylic acid.

References

Tricarboxylic acids Aconitase inhibitors