Purification and characterization of enolase from neuroblastoma cell line NG108

Neuroblastoma Cell line NG108 (a hybrid from Chinese hamster and mouse) produces high levels of enolase. Using ion-exchange chromatography and gel filtration, we have purified the enzyme (about 19 fold purification) and characterized it. The purified enzyme is a dimer of 90,000 m.wt. and is stable at room temperature. At higher temperatures (e.g., 50 degrees, 60 degrees C etc.) it gets inactivated. Enolase requires Mg++ for its activity and is resistant to urea. The optimum pH for the enzyme is 7, and Km values for Mg++ and 2-phosphoglycerate were found to be 3.1 and 1.1 mM, respectively. Fluorophosphate is a strong inhibitor of the enzyme. The clinical applications of the enzyme have been discussed.