L-idonate 5-dehydrogenase

L-Idonate 5-dehydrogenase is an enzyme that catalyzes the oxidation of L-idonate to 5-keto-gluconate in the pentose phosphate pathway, a metabolic pathway parallel to glycolysis that generates NADPH and pentoses (5-carbon sugars) as well as ribose 5-phosphate, a precursor for the synthesis of nucleotides. This enzyme plays a crucial role in cellular processes by contributing to the biosynthesis of nucleic acids and the maintenance of the redox state of cells.

Function

L-Idonate 5-dehydrogenase is involved in the metabolism of carbohydrates, specifically in the oxidative branch of the pentose phosphate pathway. The enzyme facilitates the conversion of L-idonate, a derivative of glucose, into 5-keto-gluconate. This reaction is significant as it contributes to the cellular production of NADPH, a reducing agent that is essential for the biosynthesis of fatty acids and steroids, and for the detoxification of reactive oxygen species.

Structure

The structure of L-Idonate 5-dehydrogenase has not been fully elucidated but is believed to be similar to other dehydrogenases, consisting of a protein with a binding site for the substrate (L-idonate) and a site for the coenzyme NAD(P)+, which is reduced to NADPH in the reaction.

Clinical Significance

While the direct clinical implications of L-Idonate 5-dehydrogenase are not extensively documented, enzymes of the pentose phosphate pathway, including L-Idonate 5-dehydrogenase, are of interest in the study of certain metabolic disorders and cancers. The pentose phosphate pathway's role in producing NADPH is crucial for the survival of rapidly dividing cells, including cancer cells, making enzymes of this pathway potential targets for cancer therapy.

See Also

• Pentose phosphate pathway
• NADPH
• Metabolism
• Dehydrogenase

External Links

• Link to a relevant external website about L-Idonate 5-dehydrogenase