isoleucine catabolic process

Definition

Target type: biologicalprocess

The chemical reactions and pathways resulting in the breakdown of isoleucine, (2R*,3R*)-2-amino-3-methylpentanoic acid. [GOC:ai]

The isoleucine catabolic process is a complex metabolic pathway responsible for the breakdown of the essential amino acid isoleucine into energy and other metabolic intermediates. It is crucial for the overall energy production and metabolism within the cell. The process begins with the activation of isoleucine by isoleucyl-tRNA synthetase, which attaches isoleucine to a transfer RNA molecule. This activated isoleucine is then transported into the mitochondria, the powerhouse of the cell, where the catabolic process takes place. The first step involves the conversion of isoleucine to α-keto-β-methylvalerate by the enzyme isoleucine dehydrogenase. This reaction requires the cofactor NAD+ and releases ammonia. α-keto-β-methylvalerate is then decarboxylated by the enzyme α-keto-β-methylvalerate decarboxylase to form isovaleryl-CoA, which is further metabolized through a series of reactions. The isovaleryl-CoA enters the propionyl-CoA pathway, a crucial branch of the catabolic pathway for branched-chain amino acids. Here, it undergoes several enzymatic steps including oxidation, hydration, and decarboxylation, leading to the formation of propionyl-CoA. This pathway involves the enzymes isovaleryl-CoA dehydrogenase, methylmalonyl-CoA mutase, and propionyl-CoA carboxylase. Propionyl-CoA can then be utilized for energy production by entering the citric acid cycle. Overall, the isoleucine catabolic process is a vital pathway in cellular metabolism, providing energy and essential metabolic intermediates while ensuring the proper utilization of this essential amino acid.'
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Proteins (1)

Compounds (1)