isocitrát

Isocitrate is an isomer of citrate, a key intermediate in the citric acid cycle. In biochemistry, it is typically encountered as the anion isocitrate. It is formed from citrate by the enzyme aconitase, which catalyzes a reversible isomerization reaction. Isocitrate then undergoes oxidative decarboxylation catalyzed by isocitrate dehydrogenase, a crucial regulatory step in the citric acid cycle. This reaction produces alpha-ketoglutarate, carbon dioxide, and NADH. Isocitrate plays a role in cellular respiration, providing energy by feeding into the electron transport chain via NADH. In addition to its role in the citric acid cycle, isocitrate is also involved in other metabolic pathways. For instance, it is a substrate for isocitrate lyase in the glyoxylate cycle, a pathway found in plants, bacteria, and fungi that allows them to synthesize carbohydrates from fatty acids. The concentration of isocitrate within cells is tightly regulated, reflecting its central position in energy metabolism. Mutations in enzymes involved in isocitrate metabolism can lead to various metabolic disorders.