A bioluminescent assay for enolase (EC 4.2.1.11) activity in human serum and cerebrospinal fluid

A simple method is described for the measurement of enolase enzyme activity in human serum and in unconcentrated cerebrospinal fluid. The enzyme is measured by a bioluminescent assay, making use of the luciferine/luciferase system. The method is very suitable for use in clinical chemical laboratories. The Michaelis-Menten constants of three enolase isozyme forms have been measured. Data concerning the in vitro stability at 37 degrees C of alfa-alfa, alfa-gamma and gamma-gamma enolase in cerebrospinal fluid are presented. The gamma-gamma form is the most stable enolase form under these conditions. Preliminary data from a clinical study about the diagnostic significance of the enzyme indicate that evident elevations in cerebrospinal fluid enolase levels can be seen in patients from neurological wards. There is a poor correlation between total creatine kinase and enolase cerebrospinal fluid levels.