Enolase 2

Enolase 2, also known as neuron-specific enolase (NSE) or gamma-enolase, is an enzyme belonging to the enolase family. In humans, it is encoded by the ENO2 gene.

Enolase 2 is a glycolytic enzyme that catalyzes the conversion of 2-phosphoglycerate (2-PG) to phosphoenolpyruvate (PEP) in the penultimate step of glycolysis. It is predominantly found in neurons and neuroendocrine cells, although it can also be present in other cell types to a lesser extent. Due to its high concentration in neurons, Enolase 2 has been widely used as a marker for neuronal differentiation and damage.

Elevated levels of Enolase 2 in serum or cerebrospinal fluid can indicate neuronal injury or death, and are therefore sometimes used as a diagnostic or prognostic marker in conditions such as stroke, traumatic brain injury, and neurodegenerative diseases. It is also used as a tumor marker, particularly for small cell lung cancer, neuroblastoma, and other neuroendocrine tumors. However, elevated NSE levels are not specific to these conditions, and other factors such as hemolysis or renal failure can also affect its concentration, limiting its diagnostic utility.

The ENO2 gene is located on chromosome 12p13.3. Genetic variations in the ENO2 gene have been associated with certain neurological disorders and susceptibility to certain cancers, although further research is required to fully elucidate the role of these variations.