Purification and characterization of neuron-specific gamma gamma enolase from human neuroblastoma: comparison with the brain enzyme

Neuron-specific gamma gamma enolase was purified from a neuroblastoma tissue obtained at surgical resection. The final preparation showed a single band on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) with a mobility identical to that of gamma gamma enolase purified from human brain. The values of specific activity (about 80 units/mg), optimal pH (6.9), and Km for 2-phosphoglycerate (about 3 X 10(-5) M) of gamma gamma enolase purified from neuroblastoma were very similar to those of gamma gamma enolase purified from brain. The results of peptide mapping analysis after limited proteolysis, and amino acid analysis also indicate there was no difference between the enzymes purified from neuroblastoma and brain.