Properties and application to immunoassay of monoclonal antibodies to neuron-specific gamma gamma enolase.

Two monoclonal antibodies to human and bovine neuron-specific gamma gamma enolase have been produced in the isolated hybrid cell lines, which were obtained by fusion between gamma gamma-immunized mouse spleen cells and mouse myeloma cells (P3-NS-1/1-Ag4-1), followed by a screening procedure with an enzyme immunoassay. The monoclonal antibody to human gamma gamma enolase (E1-G3) and that to bovine gamma gamma enolase (B1-D6) consisted of gamma 2a/kappa and gamma l/kappa immunoglobulin chains, respectively. Both antibodies could bind with the respective antigen with a molar ratio of about 1:1, and were found to be specific for the gamma subunit of enolase, showing reactivities with human gamma gamma and alpha gamma, rat gamma gamma and alpha gamma, and bovine gamma gamma enolases. However, the antibodies did not cross-react with the alpha or beta subunit of human and rat enolase isozymes. Both antibodies could partially inhibit the activity of gamma gamma and alpha gamma enolases. E1-G3 antibody inhibited gamma gamma and alpha gamma enolase activity by 70 and 30%, respectively, and B1-D6 antibody, by 90 and 40%, respectively. Both antibodies had no effect on the activity of alpha alpha and beta beta enolases of human and rat origins. The applicability of E1-G3 and B1-D6 antibodies to the sandwich-type enzyme immunoassay for neuron-specific enolase (enolase gamma subunit) was examined, and it was found that the assay system using E1-G3 and B1-D6 as the labeled antibodies were sufficiently sensitive for the assay of serum neuron-specific enolase concentrations.