Isocitrate Dehydrogenase I (IDH I) is an essential enzyme that plays a crucial role in the citric acid cycle, also known as the Krebs cycle or tricarboxylic acid (TCA) cycle. It is a key component in the metabolic pathway that converts carbohydrates, fats, and proteins into energy for cellular processes.
IDH I catalyzes the oxidative decarboxylation of isocitrate, a key step in the citric acid cycle. This enzyme is specifically involved in the conversion of isocitrate to alpha-ketoglutarate, utilizing NAD+ as a coenzyme. During this process, a carbon atom is removed from isocitrate in the form of carbon dioxide, producing alpha-ketoglutarate.
The reaction catalyzed by IDH I is crucial for the production of reducing agents, such as NADH, which are essential for ATP synthesis in the mitochondria. It also provides intermediates for other metabolic pathways, including the synthesis of amino acids and other important cellular components.
Mutations in the gene encoding IDH I have been linked to various diseases, including certain forms of cancer. These mutations result in a gain-of-function activity, leading to the production of an abnormal form of alpha-ketoglutarate, called 2-hydroxyglutarate. This metabolite has been found to disrupt cellular processes and contribute to the development and progression of cancer.
Overall, IDH I is an enzyme that plays a vital role in cellular energy production and metabolism. Its functions in the citric acid cycle are crucial for maintaining proper cellular function and are essential for overall organismal health.
