Gluconolactonase

Gluconolactonase is an enzyme that plays a crucial role in the metabolism of carbohydrates. It is involved in the pentose phosphate pathway, a metabolic pathway parallel to glycolysis, which generates NADPH and pentoses (5-carbon sugars) as well as ribose 5-phosphate, the latter a precursor for the synthesis of nucleotides.

Function[edit | edit source]

Gluconolactonase catalyzes the hydrolysis of D-glucono-1,5-lactone to D-gluconate, a reaction that is essential for the continuation of the pentose phosphate pathway. This enzyme is a member of the lactonase family and is present in a wide range of organisms, from bacteria to humans.

Structure[edit | edit source]

The structure of gluconolactonase is highly conserved among different species. It is a monomeric protein with a molecular weight of approximately 31 kDa. The active site of the enzyme contains a catalytic triad consisting of a serine, a glutamate, and a histidine residue. The enzyme also contains a metal binding site, which is usually occupied by a zinc ion.

Clinical significance[edit | edit source]

Alterations in the activity of gluconolactonase have been associated with various diseases. For example, decreased activity of this enzyme has been observed in patients with diabetes mellitus, suggesting a potential role in the pathogenesis of this disease. Furthermore, mutations in the gene encoding gluconolactonase have been linked to congenital disorders of glycosylation, a group of metabolic disorders characterized by defects in protein glycosylation.